PRACTICAL POINTERS
FOR
PRIMARY CARE
ABSTRACTED MONTHLY FROM THE JOURNALS
NOVEMBER 2004
EFFECTS OF A LOW-GLYCEMIC LOAD DIET ON RISK OF CARDIOVASCULAR
DISEASE
THE FAMILY HISTORY—MORE IMPORTANT THAN EVER
INTRADERMAL INFLUENZA VACCINE PRODUCES ADEQUATE IMMUNITY
TRIAL OF HEALTH EFFECTS OF SUPPLEMENTARY VITAMINS
DOCTOR-PATIENT SHARED MEDICAL DECISION MAKING
EFFICACY OF VACCINE IN PREVENTION OF HUMAN PAPILLOMA VIRUS
MICROALBUMINURIA IN TYPE 2 DIABETES IS PREVENTABLE
COMBINATION OF ISOSORBIDE AND HYDRALAZINE IN BLACKS WITH HEART
FAILURE
LEFT VENTRICULAR HYPERTROPHY:
THE NEXT SILENT KILLER?
MANAGEMENT OF FIBROMYALGIA SYNDROME
JAMA, NEJM, BMJ, LANCET PUBLISHED
BY PRACTICAL POINTERS, INC.
ARCHIVES INTERNAL MEDICINE EDITED
BY RICHARD T. JAMES JR. MD
ANNALS INTERNAL MEDICINE 400 AVINGER LANE,
SUITE 203
[email protected] DAVIDSON
NC 28036 USA
www.practicalpointers.org
HIGHLIGHTS AND EDITORIAL
COMMENTS NOVEMBER 2004
11-1 EFFECTS
OF A LOW-GLYCEMIC LOAD DIET ON RESTING ENERGY EXPENDITURE AND HEART DISEASE
RISK FACTORS DURING WEIGHT LOSS.
This study determined whether dietary
composition can influence the physiological adaptations of a weight-reducing
diet as assessed by resting energy expenditure. It also determined if cardiovascular risk factors would be
reduced on a low GL diet.
Randomized 39 overweight and obese adults
(BMI at least 27; age 18 to 40) to low calorie diets. All subjects were in
generally good health. Follow-up on diet = about 10 weeks.
The higher GL diet (lower-fat) was
generally consistent with National Cholesterol Education Program guidelines for
a heart-healthy diet.
Composition of the diets: Run-in diet Low-GL diet (higher fat) Higher GL diet (lower fat)
% of energy needs 100 60 60
Kcal/d 2600 1500 1500
Glycemic load 287 82 205
Carbohydrate % of total kcal 49 43 65
Fat % total kcal 37 30 18
Outcomes at 10 weeks Low GL diet Higher GL diet
A. Resting energy expenditure -96 kcal/d (- 6%) -176 kcal/d (-11%)
(Although
absolute resting energy expenditure decreased in both groups, subjects on the
low GL diet continued to burn more calories per day than those on the higher GL
diet. This would lead to more efficient and continuing weight loss, estimated
to be in the range of several pounds per year.)
B. Perception of hunger was less in the
low GL diet subjects.
C. Insulin resistance, triglycerides,
C-reactive protein, and BP improved more in the low GL diet group than in the
higher GL diet.
“Incorporation of glycemic load principles
into current dietary guidelines may aid in the treatment of obesity and
prevention of cardiovascular disease and diabetes.”
This
represents a continuing sea change in our thinking about benefits and risks of
diets. What is the most beneficial
diet? Are foods with a high glycemic
load, which lead to continuing elevations in blood glucose, just as harmful as
foods containing a high load of unsaturated fats?
Our
US diets are high in sugar. I believe that a healthy diet should contain
smaller amounts of sugar. This would suggest diets similar to the Mediterranean
diet which is established as beneficial.
In
the future, food manufacturers may be inclined to list the glycemic load of
their products (especially if they are low).
11-2 THE
FAMILY HISTORY—More Important Than Ever
“Today, with medicine poised at the dawn
of the genomic era, it is seductive to believe that such high-tech options have
already become the most important genomic tools in health care.” However, as so often happens in medicine,
new developments do not eclipse the tried-and-true method; instead, they give it
new meaning and power.
Most diseases are the result of the
interactions of multiple genes and environmental factors.
Almost every patient today has access to a
free, well-proven, personalized genomic tool that captures many of these
interactions and can serve as the cornerstone for individualized disease
prevention. This valuable tool is the family history (FH). It will remain highly relevant for years to come.
Government agencies are now spearheading a
national campaign to encourage families to record their health histories.
Thanksgiving Day, when families traditionally gather, has been designated as
the National Family History Day. This
will serve to remind us about the value of the FH.
The government has launched a web site
which allows families to collect, organize, and maintain the family history.
The
article cites several web sites. One: www.hhs.gov/familyhistory
Most
elderly patients will not have detained information about their forbearers.
Individuals now age 70 and above may not have accurate information about their
grandparents, but they can accurately add their own accounts and that of their
cousins to the FH.
11-3 DOSE
SPARING WITH INTRADERMAL INJECTION OF INFLUENZA VACCINE
This randomized trial compared the
immunogenicity and safety of intradermal vs
standard intramuscular vaccine.
Healthy young adults were randomized to a
single dose of: 1) Intramuscular injection of the standard 0.5 mL of trivalent
vaccine containing at least 15 ug of hemagglutinin per strain, or 2)
Intradermal injection of 0.1 mL containing at least 3 ug of hemagglutinin per
strain. Injections were made in the
deltoid region.
Subjects who received the intradermal
injections (1/5 the standard dose) had increases in hemagglutination-inhibition
antibody (HAI) titers by a factor of 12 to 19 for the three strains. This was
similar to the intramuscular response (factors of 7 to 15).
On day 21, seroconversion and
seroprotection rates were similar between groups.
The data clearly show that intradermal injection of 1/5 the dose
the standard dose of commercial vaccine elicits immune responses that are
similar or superior to those elicited by a full dose of vaccine given
intramuscularly to healthy young adults. It is generally accepted that the HAI
response represents a fair surrogate marker for protection.
In
times of vaccine shortage, we must decide whether to vaccinate a relatively few
intramuscularly and induce a known response, or vaccinate many more
intradermally with the hope of inducing a protective response in the majority.
At present, I would be inclined to use the full intramuscular dose in elderly
infirm persons, nursing home residents, and in those with impaired immunity and
chronic diseases such as asthma, heart and lung disease. If the supply was greatly
impaired, and I had no other choice, I would give the ID dose. Combined
half-dose IM and ID doses would save some vaccine.(And perhaps lead to greater
immunity.)
The
possibility of a pandemic of flu (predicted by many authorities as inevitable)
would make ID vaccination more applicable.
Obviously
the ID dose is preferable to no dose. I believe smaller doses, both IM and ID,
will produce an adequate response in many persons.
Make
sure the injection is not made into fat tissue. Immune response will be
inadequate. In very obese persons, an intradermal injection may be
preferable. The standard needle might
not reach muscle.
I
remember a vaccine shortage in the late 1950s or early 60s. We opted to give
(on an empirical basis) intradermal vaccine to many more recipients than would
have received it if the vaccine were given IM at full dose.. We had no data on
the response. Now it seems this was not such a bad idea.
11-4 THE
SU.VI.MAX STUDY: Trial of Health Effects of Supplementary Antioxidants.
This study tested the efficacy of nutritional doses of supplements
containing a mixture of antioxidant vitamins and minerals in reducing incidence
of cancer, CVD, and all-cause mortality in a general population.
Subjects were randomized to: 1) vitamin-mineral supplement, or 2) placebo
daily
The daily supplement contained:
Ascorbic acid 120 mg
Vitamin E 30
mg
Beta-carotene 6 mg
Selenium 100
ug
Zinc 20
mg
There was a statically significant
protective effect in men, but not in women:
Cancer incidence in men:
Intervention 3.5%; Placebo
4.9%. Absolute difference =
1.4% NNT 7 years = 71
Total mortality in men
Intervention 1.6%; Placebo
2.5% Absolute difference =
0.9 NNT 7 years = 111
The authors speculate that the difference
in outcomes of men vs women might be
due to a generally lower intake and plasma concentration of antioxidants
(especially beta-carotene) in men. Indeed, baseline serum concentrations were
lower in men.
The study reinforces the general
recommendation of a life-long diversified diet containing an abundance of foods
rich in antioxidants.
Is
the putative benefit of supplements clinically important? I believe it is.
How
can we apply this information to primary care in the USA?
I
believe at this time we should advise against high doses of individual vitamins
and minerals. There is no evidence of benefit and there is evidence of possible
harm.
I believe it
is likely that any benefit from supplements will be in individuals whose
nutritional status is borderline. In primary care practice, we cannot assess
the nutritional status of every individual patient. I believe therefore that a routine recommendation for a daily
low-dose supplement for adults is reasonable. Although in adequately nourished
individuals this may not bring any benefits in protecting against cancer or
cardiovascular disese, the supplements do contain, as an added attraction,
vitamin D and folic acid which may bring benefits.
11-5 IS PSA TESTING
STILL USEFUL?
Dr. Thomas A. Stamey (Stanford University
School of Medicine), who is considered to be the “father” of PSA testing, says
it is no longer a useful tool for screening for PC. In fact, it may be causing
unwarranted treatment for a typically slow-growing tumor. Dr. Stamey drew his
conclusions after studying over 1300 consecutive radical prostatectomies. Over
time, there was a linear decrease in most parameters associated with PC. During
the first 5 years of screening, 91% of cancers were palpable, the mean PSA was
25 ng/mL, the mean age was 64, and cancer volume was over 5 cm3. During the last 5-years of screening, 17%
were palpable, the mean PSA was 8 ug/mL, the mean age was 59, and the cancer
volume was 2.4 cm3. When PSA
screening was first introduced, high levels were associated with a 50% chance
of having a large PC for which treatment was warranted. Over the past 5 years,
the chance of having a large PC has fallen to 2%, presumably due to over
screening. “Most prostate cancers we (now)
remove need not be removed.”
An estimated 230 000 men in the USA will
be diagnosed as having PC this year; 30 000 are expected to die of PC. Dr. Stamey says the fear of dying of PC may
be disproportionate to the odds of death. One study reported that the
prevalence of PC was 8% in men in their 20s, and the percentage grew linearly
to 80% in men over 70. “It’s a cancer we all get if we live long enough.”
There is ambivalence in the
prostate-treatment community regarding screening. Some researchers remain
convinced that screening effectively detects clinically significant PC and
leads to a reduced mortality.
“Physicians continue to be concerned about
diagnosing prostate cancer at the earliest stage when it is most treatable,
while at the same time avoiding unneeded biopsies and treatment for prostate
cancers that might not become clinically meaningful.”
The mortality rate from the disease is
low. But the reality is that some patients may benefit from early detection.
Thus, PSA has lost some value, but it still may have some clinical relevance.
Patients at risk of overtreatment have a low, stable
PSA with low-grade, low-volume cancers. We are detecting many low volume
cancers that may not require treatment
No
doubt many men are now undergoing unnecessary treatments for PC. Undoubtedly
some lives are saved. Where to draw the line?
I
believe PSA should not be considered a “routine” screen (as is BP, blood
glucose, and cholesterol). Patients should be fully informed about risks and
benefits beforehand. I believe primary care clinicians should not even broach
the subject when consulting with elderly men. Digital rectal examination is a
more reasonable screen.
There
are some guidelines when results of PSA are obtained in younger men. If the PSA
is high, and if the rate of increase is rapid (eg, doubling time, or an
increase of over 2.0 ug/year), biopsy is warranted. Surgery then depends on the
grade of PC determined by biopsy.
When
I was a child, almost all children and many adults underwent tonsillectomy. It
seemed to be the mode. When we would consult with our European colleagues, they
would admonish—“Hold onto your tonsils”.
I believe many man in the USA should “Hold onto your prostate”.
11-6 SHARED
MEDICAL DECISION MAKING: Problems, Process, Progress
“Sharing with a patient who faces tough choices when he or she is ill is
one of the true gifts of being in the medical profession.” The patient-physician relationship is the
sacrosanct epitome of professionalism with the goals of ensuring that patients receive
the treatment best for them (science) and that the best treatment is carried
out in the most efficient and compassionate manner (quality and safety).
“Physicians should never make a choice for
a patient—even if the patient wants the physician to do so.” Instead, physicians should ensure that the
information used in the patient’s decision-making is reasonable for the
individual patient and that the patient understands the ramifications of
choice. “The physician should be a navigator, not a pilot.”
The consequences of a patient’s choice
cannot be shared with anyone else. Only the patient will suffer or enjoy the
probabilistic outcomes associated with choosing one option over another. Only
the patient will know how he or she feels about experiencing an adverse effect of
a treatment or a reduced chance of an adverse outcome that a treatment is
designed to alter. Patients must have time to reflect.
A decision that appropriately involves a
patient requires viable options, and choosing one option over another must
engender some element of risk. There has to be a definable trade-off of harm
and benefit.
Some actions, however, are not really
decisions to be made by the patient and do not require a patient’s input.
Patients need not decide if antibiotics are required for bacterial pneumonia.
Sick patients should not be allowed to make decisions about treatments that are
of clear value and that do not create significant levels of harm. If the
significance of an adverse effect or harm is so minor compared with the
benefit, no decision is required.
The conceptional framework for making a
choice is understandable as a balance between harms and benefits weighed by the
patient’s values for gains and losses. Only the patient can do it. “Physicians
cannot deny patients the opportunity and means to make their own choices.”
I
enjoyed this thought-provoking commentary.
The
demise of physician’s paternalism and authoritarianism has transferred some
decision-making to the patient. In some circumstances, the physician’s
responsibility must be to fully inform patients of the best evidence about
harms as well as benefits of treatment. This enables patients to choose based
on their individual circumstances. How strictly should primary care
clinicians apply this principle?
Shared
decision-making is applicable when the choices are “tough”. I believe the process needs to be applied to
relatively few patients seen in daily primary care practice. If this process
were applied to every patient, practice would grind to a halt. The process
would be more applicable to patients seen in specialty care (eg, oncology,
surgery).
The comment about no need for patient- decision-making in clear-cut situations such as antibiotics for pneumonia may not be so simple for an elderly, infirm patient who does not wish to receive therapy. If the patients is competent and wishes to avoid therapy, this is his decision.
There
are many obstacles to application of “shared decision” in the real world of
primary care:
The
patient may be incompetent.
What
about decisions for children?
Patients
are often medically illiterate.
There
may be cultural and language barriers. In some cultures, patients may rely on
family and will refuse to make their own choice. Some patients may defer to the physician asking “What would you
do?” and may refuse to choose..
Estimates
of benefit/harm may not apply to individual “real world” patients. The true
benefit/harm ratio may not be well established. It may be subject to change as
more information becomes available.
The patient’s best choice is often not available. The patient may not be able to pay for the choice he makes. Insurance may not cover the costs.
How should
the clinician respond when the patient chooses a course the physician considers
futile?
I
believe medical paternalism and authoritarianism is not dead yet.
11-7 EFFICACY
OF BIVALENT L1 VIRUS-LIKE PARTICLE VACCINE IN PREVENTION OF INFECTION WITH
HUMAN PAPILLOMA VIRUS TYPES 16 AND 18 IN YOUNG WOMEN.
“Persistent infection with high-risk HPV
types is the necessary cause of cervical cancer.” HPV-18 and HPV-16 are the
most prevalent types.
This study determined if vaccination
against the common oncogenic types of HPV (16 and 18) could prevent development
of cervical infection.
Double-blind trial randomized over 1100
healthy women between ages 15 and 25. All were initially cytologically negative
and seronegative for 16 and 18, and negative for HPV-DNA by PCR.
Randomized to: Three injections of: 1) HPV 16/18 vaccine formulated with an
adjuvant, or 2) Placebo injections at months 0, 1, and 6.
Vaccine efficacy against incident
infection with 16/18 was 92%. Efficacy against persistent infection was 100%.
It was 93% effective against cytological abnormalities associated with 16/18.
Three episodes of atypical squamous cells of undetermined significance occurred
in the vaccinated group; 33 in the placebo group
The vaccine was generally safe, well
tolerated, and highly immunogenic.
Other
HPV types also cause cervical cancer. The final composition of the vaccine
remains to be determined.
The long-term
protective effect is still not clear.
This
is very exciting—likely to be the first vaccine to prevent cancer, and the
first licensed vaccine to prevent a sexually transmitted disease.
Worldwide
implementation might be an impossible task.
11-8
PREVENTING MICROALBUMINURIA IN TYPE 2 DIABETES.
This study was designed to assess whether
an angiotensin-converting-enzyme inhibitor or a non-dihydropyridine
calcium-channel blocker, or the combination, would prevent microalbuminuria in patients with DM2 who had hypertension
and normal urinary albumin excretion.
Mean trough BP attained: Development of
microalbuminuria (%):
Trandolapril alone 139/81 Trandolapril
alone 6
Verapamil alone 141/82 Verapamil
alone 11.9
Both 139/80 Both 5.7
Placebo 142/83 Placebo 10
Trandolapril alone significantly reduced
the incidence of microalbuminuria in patients with DM2.
(NNT 4 years = 25)
In subjects with DM2 and hypertension, normoalbuminuria,
and normal renal function, ACE-inhibitor therapy with trandolapril prevented
the onset of microalbuminuria. A calcium blocker did not.
Should
all patients with DM2 receive an ACE inhibitor regardless of BP or
microalbuminuria? This study would tilt toward this application. Patients with
DM2 who have hypertension (systolic > 130) will likely develop
microalbuminuria eventually.
COST: Drug store.com quotes telmisartan (Mavix 2
mg) about $1 per day
Enalapril
(Generic 20 mg) about 20 cents.
Note
that the target BP was not reached. ACE inhibitors have effects on the
vasculature of the kidney and other endothelium exceeding their effect on BP.
What
about angiotensin II blockers? A companion study in this issue of NEJM (pp
1952-61), first author Anthony H Barnett, University of Birmingham, Alabama,
reports that the angiotensin II blocker telmisartan was as effective (but not
more effective) than the ACE inhibitor enalapril (Generic) in providing
long-term renoprotection in DM2. At present, ACE inhibitors are first-line
therapy. Angiotensin II inhibitors are reserved for those who cannot tolerate
ACE.
11-9
COMBINATION OF ISOSORBIDE AND HYDRALAZINE IN BLACKS WITH HEART FAILURE
Endothelial dysfunction, impaired
bioavailability of nitric oxide, and increased oxidant stress occur in HF.
Augmentation of nitric oxide (by the nitric oxide donor, isosorbide) may be an
alternative or supplemental approach to treatment of HF. Hydralazine may confer
protection against degradation of nitric oxide induced by oxidative stress.
Studies have suggested that persons who
identify themselves as black may have a less active renin-angiotensin system,
and lower bioavailability of nitric oxide than those self-identified as white.
This study examined whether a fixed dose
of isosorbide/hydralazine would provide additional benefits in blacks with
advanced HF.
Black patients with grade III & IV HF
were randomized to: 1) A fixed dose of isosorbide/hydralazine
given by mouth daily, or 2) Placebo.
Dose = 37.5 mg hydralazine + 20 mg isosorbide dinitrate three times
daily. Dose could be increased to a total
of 225/120 mg daily depending on absence of drug-induced side effects.
The study was terminated early owing to a
significantly higher mortality in the placebo group.
(10% vs 6%; absolute difference = 4%; NNT for 10
months = 25)
There was an absolute reduction in first
hospitalization for HF of 10%; and improvement in the quality-of-life score vs placebo of 2 points in a scale of 0
to 105.
Would
not white persons also benefit?
This
remarkable study was facilitated by the Association of Black Cardiologists. It
included patients from 161 centers. It needs independent confirmation. The
study was supported by NitroMed. I wondered why a drug company would sponsor a
study of drugs which can be readily obtained in generic form.
There
is a substantial problem in classifying individuals in the USA as “black”, and
lumping them together as African-American. See the following commentary.
11-10
A RATIONAL BASIS FOR RACE
Humans are not divided along clear
color-based lines which are traditionally used in anthropological records. Some
ask—Does race exist at all?
The problem occurs when society and the
medical community generalizes findings to an entire group. Prostate cancer has
a higher prevalence among African-American men. This does not mean that all
African-American men have similar risks for prostate cancer.
The connection between self-identified
race and genetic variation is very blurry. Culture, lifestyle, and social
stress may play a greater role in disparity.
Black
“African Americans” are an extremely diverse group.
We
often choose subsets of individuals for screening—race may be one. I believe
divisions according to ‘race” still has some clinical validity. The disparity
between races in the USA is gradually disappearing.
11-11
LEFT VENTRICULAR HYPERTROPHY: The Next
Silent Killer?
Even mild increases in BP are associated
with increased left ventricular mass (LV
mass).
Left ventricular hypertrophy (LVH) is a risk factor for premature
death and cardiovascular events. The Framingham study has reported that LVH, as
confirmed by ECG, is associated with a mortality rate as high as that
associated with a Q-wave myocardial infarction.
LVH associated with hypertension appears
to be reversible. A long-term reduction in BP is associated with reductions LV
mass.
Two articles in this issue of JAMA report
that reductions in left ventricular mass in the setting of treatment for
hypertension correlate with long-term cardiovascular outcomes. The first trial
of hypertensive patients with LVH documented by ECG criteria, reported the
greater the treatment-decrease in ECG markers of LVH, the greater the reduction
in cardiovascular events. The second
trial reported data obtained by echocardiography. Over time, reductions in LV
mass with treatment of hypertension were associated with reduced risk of
cardiovascular events.
“Active efforts to reduce left ventricular
mass may have important clinical benefits.”
Treatment to reduce LV mass may follow a course similar to reductions in
cholesterol and BP.
I
believe this is a clinically important point. Many primary care clinicians will
have ECG available. If LVH is present, extra efforts should be taken to treat
hypertension. A more careful follow-up
is warranted.
11-12
MANAGEMENT OF FIBROMYALGIA SYNDROME
The diagnosis of the fibromyalgia syndrome
(FMS) is based on a history of
widespread chronic, bilateral upper body, lower body, and spine pain, and the
presence of excessive tenderness on applying pressure to 11 or more of 18
specific muscle-tendon sites. FMS has not been traced to any specific
structural or inflammatory cause.
FMS is the second most common disorder
observed by rheumatologists (after osteoarthritis). It has a prevalence of 2%
in the US. It is much more common in women. Chronic pain syndromes such as FMS
are defined by subjective symptoms. No discrete boundary separates FMS from
chronic fatigue syndrome, irritable bowel syndrome, and chronic muscular
headache. Mood disturbances are comorbid with all.
This article summarizes the findings of a
report (based on a detailed literature search) commissioned by the American
Pain Society to provide evidence-based guidelines for the optimal management of
FMS. There are major limitations to the literature. Many treatment trials are
of short duration and lack masking. No medical therapies have been specifically
approved by the FDA.
Despite the chronicity and complexity of
FMS, there are interventions that may have clinical benefit in primary care
practice. Several drugs and non-medical therapies are suggested.
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which have appeared in the flagship journals.
Richard James, M.D.
Editor
ABSTRACTS NOVEMBER 2004
11-1 EFFECTS OF A LOW-GLYCEMIC LOAD DIET ON RESTING
ENERGY EXPENDITURE AND HEART DISEASE RISK FACTORS DURING WEIGHT LOSS.
The poor long-term efficacy of
conventional obesity treatment has promoted the notion of a body weight settling point. Deviations in body
weight from baseline elicit physiological adaptations that antagonize further
weight change. During energy restriction, hunger increases (leading to
increased energy intake), thyroid hormone levels decrease, and reproductive and
growth functions are down-regulated (leading to lower energy expenditure). The
body weight settling point may best
be conceptualized as representing the integrated influences of numerous
genetic, behavioral, and environmental factors.
Resting energy expenditure (REE) declines as a result of weight
reduction.
Glycemic load (GL) is the glycemic index of each food multiplied by the total
carbohydrate amount ingested. It measures the increase in blood glucose
following a meal. A high glycemic load diet appears to stimulate hunger and to increase
voluntary food intake. A recent study examined the effects that glycemic load
on REE. After 1 week of an energy-restricted diet providing 50% of predicted
total energy requirements, REE decreased by 10% when the diet was high glycemic
load compared with 5% when the diet was low-glycemic load. (Ie, REE seems to be
lower when high glycemic index foods are provided in a weight-reduction diet,
and higher when a low glycemic index diet is provided.) The resulting higher REE (associated with
foods low in GL) would lead to greater continuing weight loss.
This study determined whether dietary
composition can influence the physiological adaptations of a weight-reducing
diet as assessed by REE. It also
determined if cardiovascular risk factors would be reduced on a low GL diet.
Conclusion: A low glycemic load (low
sugar) diet may aid in the prevention and treatment of obesity, cardiovascular
disease, and diabetes.
STUDY
1. Randomized 39 overweight and obese
adults (BMI at least 27; age 18 to 40) to low calorie diets. All subjects were
in generally good health. Follow-up on diet = about 10 weeks.
2. Performed sophisticated metabolic
studies during a run-in period with subjects on a weight-maintaining diet. And
repeated the studies at the end of the 10-week restricted diet.
3. Randomized to: 1) a low glycemic-load
diet [lower carbohydrate; higher fat], or 2) a higher GL diet [lower fat
;higher carbohydrate]. Both diets
provided 60% of predicted energy requirements.
4. The mean daily predicted glycemic load
was calculated as grams of available carbohydrate multiplied by the glycemic
index of each food (using white bread as 100%) and summed over all foods.)
5. The higher GL diet (lower-fat) was
generally consistent with National Cholesterol Education Program guidelines for
a heart-healthy diet.
6. The low GL diet was designed to be as
low in glycemic load as possible, while providing more than ample carbohydrate
to prevent ketosis.
7. Composition of the diets: Run-in diet Low-GL
diet (higher fat) Higher GL
diet (lower fat)
% of energy needs 100 60 60
Kcal/d 2600 1500 1500
Glycemic load 287 82 205
Carbohydrate % of total kcal 49 43 65
Fat % total kcal 37 30 18
RESULTS
1. Participants in both groups lost weight
equally—about 10% of their initial weight.
2. Outcomes at 10 weeks Low GL diet Higher GL diet
A. Resting energy expenditure -96 kcal/d (- 6%) -176 kcal/d (-11%)
(Although
absolute resting energy expenditure decreased in both groups, subjects on the
low GL diet continued to burn more calories per day than those on the higher GL
diet. This would lead to more efficient, and continuing weight loss.)
B. Perception of hunger was less in the
low GL diet subjects,
C. Insulin resistance, triglycerides, C-reactive protein, and BP improved more in the low GL diet group than in the higher GL diet.
DISCUSSION
1. “The primary finding of this study was
that physiological adaptations that serve to defend baseline body weight can be
modified by dietary composition.” On the low GL diet, REE declined by 96 kcal/d
during weight loss vs a decline of
176 kcal/d in the higher GL diet.
2. The low GL diet produced favorable
changes in insulin resistance, chronic inflammation, lipids, and BP compared
with a conventionally recommended (higher GL) diet which was lower in saturated
fat, cholesterol, and sodium.a
3. The REE difference could amount to
weight loss of several pounds per year. An energy balance of – 80 kcal/d equals
approximately that of walking 1 mile per day, or by decreasing sugar-sweetened
soft drink consumption by 6 oz/day.
4. Epidemiological analyses have found
associations between GL and high triglycerides, low HDL-cholesterol, and
elevated c-reactive protein. A higher GL diet has also been associated with a
higher risk of developing heart disease.
5. “We found that during weight loss, a
diet focused on glycemic load reduction produced greater improvements in
several important cardiovascular disease-related and diabetes-related endpoints
than a diet focused on reduction of total and saturated fat in accordance with
conventional practice.
6. “Incorporation of glycemic load
principles into current dietary guidelines may aid in the treatment of obesity
and prevention of cardiovascular disease and diabetes.”
CONCLUSION
Physiological
adaptations to a weight-reducing diet thought to antagonize ongoing weight
loss, involving energy expenditure and hunger, can be modified by dietary
composition.
A low
glycemic load diet had beneficial effects on several obesity-related factors.
JAMA November 24, 2004,
292: 2482-90 Original
investigation, first author Mark A Pereira, Children’s Hospital, Boston Mass.
a See p 2485
for sample menus of both diets.
========================================================================
We Need to Make the Process of Collecting and
Analyzing the Data Easier and Less Time Consuming.
11-2 THE FAMILY HISTORY—More Important Than Ever
“Today, with medicine poised at the dawn
of the genomic era, it is seductive to believe that such high-tech options have
already become the most important genomic tools in health care.” However, as so often happens in medicine,
new developments do not eclipse the tried-and-true method; instead, they give
it new meaning and power.
Most diseases are the result of the
interactions of multiple genes and environmental factors.
Almost every patient today has access to a
free, well-proven, personalized genomic tool that captures many of these
interactions and can serve as the cornerstone for individualized disease
prevention. This valuable tool is the family history (FH). It will remain highly relevant for years to come.
The FH predicts the risk of varied health
concerns: heart disease, colorectal
cancer, breast cancer, ovarian cancer, osteoporosis, asthma, type 2 diabetes,
early stroke, and suicide, among many others.
Many patients are not aware of their FH.
Many health professionals underuse this information in advising patients about
how to maintain good heath.
The FH has long been regarded as a
mainstay in caring for patients who are at increased risk of relatively
uncommon, Mendelian (single gene) conditions:
von Willebrand’s disease, polycystic kidney disese, sickle cell disease,
fragile X syndrome, hereditary hemorrhagic telangiectasia.
We do our patients a disservice if we fail
to realize the value of FH in dealing with more common, multifactorial
disorders as well. Many of those listed above are just as important on the
paternal side as on the maternal side. By assessing a person’s pretest risk,
the FH can substantially alter the predictive value of screening tests.
We need to make the process of collecting
and analyzing the FH data easier and less time consuming.
Government agencies are now spearheading a
national campaign to achieve this goal. Thanksgiving Day, when families
traditionally gather, has been designated as the National Family History Day. This will serve to remind us about the
value of the FH.
The government has launched a web site
which allows families to collect, organize, and maintain the family history.
Someday, perhaps not far off, detailed
genotypic information will play an important and everyday role in guiding
patient care. Meanwhile, it is important not to overlook what patients know
about the health of their families.
NEJM November 25, 2004;
351: 2333-36 “Sounding Board”,
commentary, first author Alan E Guttmacher, National Human Genome Research
Institute, National Institutes of Health, Bethesda, MD.
========================================================================
Intradermal Injection Elicited Immunity in Healthy
Young Adults
11-3 DOSE SPARING WITH INTRADERMAL INJECTION OF
INFLUENZA VACCINE
Dose-sparing strategies are now being
studied in view of the critical shortage of flu vaccine this year,
This randomized trial compared the
immunogenicity and safety of intradermal vs
standard intramuscular vaccine. The immune system in the skin has been
recognized as a desirable target for vaccination. The barrier function of the
skin’s immune system can be exploited for vaccination. Over 25% of the
body-surface area is covered by dendritic cells, a form of antigen-presenting
cell whose function is to recognize foreign antigens and initiate an effective
immune response.
Delivery into the skin is effective for
several vaccines (eg, bacille Calmette-Guerin; smallpox)
Intramuscular injection of vaccine
bypasses the skin’s immune system and delivers antigens into tissue that has no
important resident population of antigen-presenting cells. Antigen delivered to
muscle tissue is thought to be picked up by transient antigen-presenting cells
or simply to circulate to the draining lymph node. Only small volumes of fluid
can be injected into the skin. Direct dose-to-dose comparisons are difficult to
conduct.
Conclusion: In young adults, immune responses were similar.
STUDY
1. Randomized, open-label trial entered
100 healthy adults age 18 to 40.
2. Randomized to a single dose of: 1)
Intramuscular injection of 0.5 mL of
trivalent vaccine containing at least 15 ug of hemagglutinin per strain, or 2)
Intradermal injection of 0.1 mL containing at least 3 ug of hemagglutinin per
strain. Injections were made in the deltoid region.
3. Measured changes in
hemagglutination-inhibition antibody (HAI) titers. Compared seroconversion and seroprotection rates.
RESULTS
1. Subjects who received the intradermal
injections (1/5 the standard dose) had increases in hemagglutination inhibition
antibody titers by a factor of 12 to 19 for the three strains. This was similar
to the intramuscular response (a factor of 7 to 15).
2. On day 21, seroconversion and
seroprotection rates were similar between groups.
3. Local reactions were significantly more
frequent among the intradermal recipients. But reactions were mild.
DISCUSSION
1. “Our results support the use of a
dose-sparing strategy for influenza vaccination.” The data clearly show that,
in healthy young adults, intradermal injection of 1/5 the standard dose of
commercial vaccine elicits immune responses that are similar or superior to
those elicited by a full dose of vaccine given intramuscularly. It is generally
accepted that the HAI response represents a fair surrogate marker for
protection.
2. Standard tuberculin syringes and
needles can be used with multidose vials of vaccine to increase the supply by a
factor of about 5.
3. It is possible that elderly persons and
young children or those with underlying medical conditions may not respond as
well.
CONCLUSION
Intradermal injection of 1/5 the dose of
influenza vaccine in healthy young adults elicited immunogenicity similar to
the response to full-dose intramuscular vaccine.
NEJM November 25, 2004;
351: 2295-301, Original investigation, first author Richard T Kenney,
Iomai, Gaithersburg, Maryland.
Several other articles addressing this
issue appeared in NEJM
“Serum Antibody Responses after
Intradermal Vaccination against Influenza”, NEJM November 25.2004; 351: 2286-94, first
author Robert B Belshe, Saint Louis University, St. Louis, MO reported similar
responses to intradermal injections among persons age 18 to 60, but not among
those over age 60. The vaccine was given intradermally by a novel tuberculin
syringe with a 30-guage beveled needle that protruded 1.5 mm from a plastic
disk to limit skin preparation, thus ensuring administration intradermally.
This would facilitate administration to large groups.
“Influenza Vaccination with 1/10 the Full
Dose” NEJM
November 25, 2004; 351: 2339-40 “Correspondence to the Editor”, first
author Curtis L Cooper, University of Ottawa, Canada, reports a study of 29 young adults randomized to: 1) a single,
intramuscular dose of 1.5 ug of each of the three hemagglutinin antigens (1/10
the regular dose, or 2) a full intramuscular dose. The resultant mean
hemagglutination-inhibition titers, although generally lower in response to the
small dose, were considered adequate for immune protection.
============================================================================
Associated with Lower Cancer Incidence and All-Cause
Mortality in Men, But Not in Women.
11-4 THE SU.VI.MAX STUDY
Epidemiological studies have shown a
strong relationship between intake of antioxidant vitamins, minerals, and foods
rich in these nutrients and the risks of cancer and cardiovascular disease
(CVD).
However, randomized, placebo-controlled primary prevention trials of these
nutrients taken in high doses have not confirmed any benefits. Some suggest
harmful effects.
This study tested the efficacy of nutritional doses of supplements
containing a mixture of antioxidant vitamins and minerals in reducing incidence
of cancer, CVD, and all-cause mortality.
Conclusion: After 7 years, low-dose supplements were associated with lower
cancer incidence and all-cause mortality in men, but not in women.
STUDY
1. A randomized, placebo controlled trial
followed over 13 000 adult men and women in a general population in France for
a median of 7.5 years. Individuals were not selected for risk factors.
2. Randomized to: 1) Vitamin-mineral supplement, or 2) Placebo
daily
3. The supplement contained:
Ascorbic acid 120 mg
Vitamin E 30
mg
Beta-carotene 6 mg
Selenium 100
ug
Zinc 20
mg
(This
is about twice the usual dose contained in supplements in the USA. Our daily
supplements contain many more vitamins and minerals. RTJ)
4. Outcomes = incidence of cancer and ischemic CVD.
RESULTS
1. There was a statically significant protective effect
in men, but not in women.
Cancer incidence in men:
Intervention 3.5%; Placebo 4.9%. Absolute difference = 1.4% NNT 7 years = 71
Total mortality in men
Intervention 1.6%; Placebo 2.5% Absolute difference = 0.9 NNT 7 years = 111
2. At baseline, average serum values of
beta-carotene and vitamin C were lower in men. When divided into quintiles of
baseline beta-carotene concentrations, the incidence of cancers in men was
lower in the highest quintile compared with the lowest quintile. (RR = 0.55).
The RR for CVD was 0.57.
3. The reduction in cancer incidence in
men extended to all types: thyroid,
genital, skin, respiratory, digestive tract, and oral cavity.
DISCUSSION
1. Antioxidants were associated with lower
cancer risk and total mortality in men but not in women.
2. There was no major effect on ischemic
CVD.
3. This trial differs from previous
primary prevention trials. It examined lower (supplementary) doses of
antioxidants, not pharmacological doses. Only one trial (in China) used a balance
of several antioxidants in nutritional doses. It reported a lower incidence of
cancer in a nutritionally compromised population.
4. The authors speculate that the
difference in outcomes of men vs
women might be due to a generally lower intake and plasma concentration of
antioxidants (especially beta-carotene) in men. Indeed, baseline serum
concentrations were lower in men.
5. The study reinforces the general
recommendation of a life-long diversified diet containing an abundance of foods
rich in antioxidants.
CONCLUSION
A well-balanced supplementation of
antioxidant nutrients at doses that might be reached with a healthy diet that
includes a high consumption of fruits and vegetables, had protective effects
against cancer and all-cause mortality in men.
Archives Int
Med November 22, 2004; 164: 2335-42 Original investigation by The Supplementation en Vitamines et Mineraux
Antioxydants (SU. VI. MAX) Study, first author Serge Hercberg, Institut
National de la Sante et de le Recherche Medical (INSERM), Paris, France.
===========================================================================
“Most Prostate Cancers We Remove Need Not Be Removed.”
11-5 IS PSA TESTING STILL USEFUL?
The American Cancer Society recommends
that physicians offer PSA testing and digital rectal examinations for prostate
cancer (PC) annually beginning at
age 50 in men who have at least a 10-year life expectancy.
Now, Dr. Thomas A. Stamey (Stanford
University School of Medicine), who is considered to be the “father” of PSA
testing, says it is no longer a useful tool for screening for PC. In fact, it
may be causing unwarranted treatment for a typically slow-growing tumor. Dr.
Stamey drew his conclusions after studying over 1300 consecutive radical
prostatectomies. Over time, there was a linear decrease in most parameters
associated with PC. During the first 5 years of screening, 91% of cancers were
palpable, the mean PSA was 25 ng/mL, the mean age was 64, and cancer volume was
over 5 cm3. During the
last 5-years of screening, 17% were palpable, the mean PSA was 8 ug/mL, the
mean age was 59, and the cancer volume was 2.4 cm3. When PSA screening was first introduced, high levels were associated
with a 50% chance of having a large PC for which treatment was warranted. Over
the past 5 years, the chance of having a large PC has fallen to 2%, presumably
due to over screening.
During the first 5 years of screening, 6
histological cancer parameters had statistically significant relationships to PSA. During the last 5 years, the only factor PSA
levels predicted was an enlarged prostate, a common occurrence in aging men.
“Most prostate cancers we (now) remove need not be removed.”
Elevated PSA levels may indicate PC, but
are also associated with benign prostate enlargement, inflammation, and
infection. Originally, a high PSA level correlated with detection of large
tumors which posed the greatest risk of death. Today, however, PSA screening
has become widespread, and testing triggers biopsy at much lower scores.
Greater numbers of small cancers are being found—cancerous tumors that do not
necessarily require aggressive treatments which can leave impotence,
incontinence, and bowel disorders.
PSA can detect PC early, but this can lead
to overly aggressive treatment. An estimated 230 000 men in the USA will be
diagnosed as having PC this year; 30 000 are expected to die of PC. Dr. Stamey says the fear of dying of PC may
be disproportionate to the odds of death. One study reported that the
prevalence of PC was 8% in men in their 20s, and the percentage grew linearly
to 80% in men over 70. “It’s a cancer we all get if we live long enough.”
There is ambivalence in the
prostate-treatment community regarding screening. Some researchers remain
convinced that screening effectively detects clinically significant PC and
leads to a reduced mortality.
The Prostate
Cancer Education Council is promoting screening nationwide. The Prostate Cancer Foundation issued a Report to the Nation on Prostate Cancer
urging improved management and treatment while noting a debate on the use of
screening and the optimal score threshold for biopsy. The foundation
commented…“Physicians continue to be concerned about diagnosing prostate cancer
at the earliest stage when it is most treatable, while at the same time
avoiding unneeded biopsies and treatment for prostate cancers that might not
become clinically meaningful.”
The mortality rate from the disease is
low. But the reality is that some patients may benefit from early detection.
Thus, PSA has lost some value, but it still may have some clinical relevance.
Once PC is diagnosed, and the patient
hears the word “cancer”, he will prefer removal to eliminate the cancer. He may
not understand the risk of adverse effects.
Patients at risk of overtreatment have a
low, stable PSA with low-grade, low-volume cancers. We are detecting many low
volume cancers that may not require treatment.
There is still no consensus. Many remain
skeptical of its value, saying it remains unknown whether it saves lives.
We need a better test. Meanwhile
surveillance to detect those with more rapid growth may be a conservative
approach.
JAMA November 17, 2004;
292: 2326-27 “Medical News and
Perspectives”, commentary by Mike Mitka, JAMA Staff
Comment:
Dr. Stamey’s report is contained in Journal of Urology October 2004
================================================================================
“A Mathematical Core Wrapped in Compassion, Humility,
and Responsibility.”
11-6 SHARED MEDICAL DECISION MAKING: Problems,
Process, Progress
“Sharing with a patient who faces tough choices when he or she is ill is
one of the true gifts of being in the medical profession.” The patient-physician relationship is the
sacrosanct epitome of professionalism with the goals of ensuring that patients
receive the treatment best for them (science) and that the best treatment is
carried out in the most efficient and compassionate manner (quality and
safety).
“Physicians should never make a choice for
a patient—even if the patient wants the physician to do so .” Instead, physicians should ensure that the
information used in the patient’s decision-making is reasonable for the
individual patient and that the patient understands the ramifications of
choice. “The physician should be a navigator, not a pilot.”
The consequences of a patient’s choice
cannot be shared with anyone else. Only the patient will suffer or enjoy the
probabilistic outcomes associated with choosing one option over another. Only
the patient will know how he or she feels about experiencing an adverse effect
of a treatment, or a reduced chance of an adverse outcome that a treatment is
designed to alter. Is the benefit of undergoing a prostatectomy for cancer
worth the chance of becoming impotent or incontinent? Only the patient can
decide. “Since no one else knows, no one else should decide.” In this sense,
“shared decisions making” does not exist.
Some actions, however, are not really
decisions to be made by the patient and do not require a patient’s input.
Patients need not decide if antibiotics are required for bacterial pneumonia.
Sick patients should not be allowed to make decisions about treatments that are
of clear value and that do not create significant levels of harm. If the
significance of an adverse effect or harm is so minor compared with the
benefit, no decision is required.
A decision that appropriately involves a
patient requires viable options, and choosing one option over another must
engender some element of risk. There has to be a definable trade-off of harm
and benefit.
“Shared medical decision making really
does not pertain to sharing choices, but rather involves sharing
information.” How do physicians inform
patients about the consequences of the choices they must make? The patient must first have something to
reflect upon. Some quality-of-life trade-off exists if the difference in the
probabilistic outcomes associated with choices is known. If not known, a choice
cannot be made. Reasonable estimates must be available for the individual’s
marginal benefit, and for the marginal harm. The patients must have time to
reflect.
The conceptional framework for making a
choice is understandable as a balance between harms and benefits weighed by the
patient’s values for gains and losses. Only the patient can do it. “Physicians
cannot deny patients the opportunity and means to make their own choices.”
“In essence, medical decision making is a
mathematical core wrapped in compassion, humility, and responsibility.”
JAMA November 24, 2004;
292: 2516-18 “Commentary ”by Robert
A McNutt, Rush University School of Medicine, Chicago, IL
==========================================================================
Efficacious in Prevention of Incident and Persistent
Cervical Infections.
11-7 EFFICACY OF BIVALENT L1 VIRUS-LIKE PARTICLE
VACCINE IN PREVENTION OF INFECTION WITH HUMAN PAPILLOMA VIRUS TYPES 16 AND 18
IN YOUNG WOMEN.
Cervical cancer is the most important
manifestation of human papilloma virus (HPV)
infection. It is one of the leading causes of cancer mortality in women
worldwide. Almost 80% of cases occur in developing countries.
High-risk HPV DNA has been discovered in
almost 100% of cases confirmed by expert histology. “Persistent infection with high-risk HPV types is the necessary
cause of cervical cancer.” HPV-18 and HPV-16 are the most prevalent types.
This study determined if vaccination
against the common oncogenic types of HPV (16 and 18) could prevent development
of cervical infection.
Conclusion: The vaccine was efficacious in prevention of incident and
persistent cervical infections.
STUDY
1. Double-blind trial randomized over 1100
healthy women between ages 15 and 25. All were initially cytologically negative
and seronegative for 16 and 18, and negative for HPV-DNA by PCR.
2. Randomized to: Three injections of: 1) HPV 16/18 vaccine
formulated with an adjuvant, or 2) Placebo injections at months 0, 1, and 6.
3. Followed for up to 27 months for HPV
infection by cervical cytology and self-obtained cervicovaginal samples.
Determined incident and persistent infections by PCR, cytological
abnormalities, and cervical carcinoma in situ. (CIN).
RESULTS
1. Vaccine efficacy against incident
infection with 16/18 was 92%. Efficacy against persistent infection was 100%.
2. It was 93% effective against
cytological abnormalities associated with 16/18. Three episodes of atypical
squamous cells of undetermined significance occurred in the vaccinated group;
33 in the placebo group.
3. The vaccine was generally safe, well
tolerated, and highly immunogenic.
DISCUSSION
1. The bivalent HPV 16/18 virus-like
particle vaccine, given over 6 months with 3 injections, was highly efficacious
in preventing incident and persistent HPV 16/18 infections.
2. The study provided evidence for the
close relation between persistent HPV infection and the development of cytological abnormalities.
3. The study was not powered to estimate
efficacy for histopathologically
confirmed cervical lesions.
4. The authors suggest that the adjuvant
enhances immune response (compared with antigen alone). The immune response from vaccination may
persist for a longer time than the response from a naturally acquired
infection.
5. If the vaccine does indeed prevent
cervical cancer, it would reduce the costs of repeated cervical screening and
treatment for cervical cancer.
CONCLUSION
A bivalent HPV vaccine was efficacious in
prevention of incident and persistent 16/18 cervical infections and associated
cervical abnormalities.
Lancet November
13, 2004; 364: 1757-65 Original
investigation by the HPV Vaccine Study Group, fist author Dianne M Harper,
Dartmouth Medical School, Hanover, NH, USA.
=============================================================================
“Microalbuminuria Can Be Prevented”
11-8 PREVENTING MICROALBUMINURIA IN TYPE 2
DIABETES.
About 1/3 of patients with type 2 diabetes
(DM2) will eventually have
progressive deterioration of renal function. Microalbuminuria is the first sign
of renal dysfunction. (Endothelial dysfunction, however, is not necessarily
confined to the kidney). When microalbuminuria develops, it is seldom
reversible. It progresses to overt proteinuria in up to 40% of patients. A high
percentage to these patients will progress to chronic kidney disease and
ultimately require dialysis.
Many patients with microalbuminuria will
die of cardiovascular disease. In patients with DM2 and renal disease, lowering
BP and the levels of urinary albumin effectively reduces the risk of
cardiovascular disease as well as end-stage renal disease.
Treatment with the ACE inhibitor enalapril
(Generic) over 6 years has been
reported to decrease the incidence of microalbuminuria in normotensive patients who had DM2. An unresolved issue is whether
any drugs can prevent
microalbuminuria in patients with DM2 and hypertension.
This study was designed to assess whether
an angiotensin-converting-enzyme inhibitor or a non-dihydropyridine
calcium-channel blocker, or the combination would prevent microalbuminuria in patients with DM2 who had hypertension
and normal urinary albumin excretion.
Conclusion: The ACE inhibitor trandolapril decreased the incidence of
microalbuminuria. The calcium blocker did not.
STUDY
1. Followed over 1200 patients with DM2.
All were over age 40 (mean age 62). All
had albumin excretion under 20 ug per minute. (Microalbuminuria was defined as
an overnight excretion of 20 to 200 ug per minute.) All had serum creatinine levels under 1.5 mg/mL, and untreated
systolic BP over 130/85.
2. At baseline, the mean duration of DM2
was 8 years; mean HbA1c 6%; trough BP 150/87; urinary albumin 5 ug/min; serum
creatinine 0.9 mg/dL.
3. Randomized to: 1) the ACE inhibitor trandolapril (Mavix 2 mg/d ), or 2) the non-dihydropyridine calcium blocker
sustained-release verapamil ( Generic 240 mg /d); 3) both; or 4) placebo.
4. The target BP was 120/80. If the target
was not reached, additional antihypertension drugs were allowed.
5. Primary end point = development of
microalbuminuria (over 20 ug/min).
6. Follow-up = 4 years.
RESULTS
1. Mean trough BP attained: Development of microalbuminuria
(%):
Trandolapril alone 139/81 Trandolapril
alone 6
Verapamil alone 141/82 Verapamil
alone 11.9
Both 139/80 Both 5.7
Placebo 142/83 Placebo 10
2. The glomerular filtration rate did not change in
any group.
DISCUSSION
1. Trandolapril alone significantly reduced the
incidence of microalbuminuria in patients with DM2.
(NNT 4 years = 25)
2. Verapamil alone or added to trandolapril had no
effect.
3. Preventing (or delaying) onset of microalbuminuria
is a key goal for reno-protection.
4. “Microalbuminuria can be prevented in type 2
diabetes.”
CONCLUSION
In subjects with DM2 and hypertension,
normoalbuminuria, and normal renal function, ACE-inhibitor therapy with
trandolapril prevented the onset of microalbuminuria.
NEJM November 4, 2004;
351: 1941-51 Original investigation
by the Bergamo Nephrologic Diabetes Complications Trial (BENEDICT)
investigators, first author Peiro Ruggenenti, Mario Negri Institute for
Pharmacological Research, Bergamo, Italy.
================================================================================
Slowed Progression of HF in Blacks
11-9 COMBINATION OF ISOSORBIDE AND HYDRALAZINE
IN BLACKS WITH HEART FAILURE
Neurohormonal inhibitors alone or in
combination slow the progression of left ventricular dysfunction, and reduce
the rates of death and complications in patients with heart failure (HF).
Endothelial dysfunction, impaired
bioavailability of nitric oxide, and increased oxidant stress occur in HF.
Augmentation of nitric oxide (by the nitric oxide donor, isosorbide) may be an
alternative or supplemental approach to treatment of HF. Hydralazine may confer protection against
degradation of nitric oxide induced by oxidative stress.
Studies have suggested that persons who
identify themselves as black may have a less active renin-angiotensin system,
and lower bioavailability of nitric oxide than those self-identified as white.
This study examined whether a fixed dose
of isosorbide/hydralazine would provide additional benefits in blacks with
advanced HF.
Conclusion:
Addition of fixed doses of isosorbide/hydralazine to standard therapy
for HF in blacks was efficacious and increased survival.
STUDY
1. Randomized over 1000 adult patients
(mean age 57) self-identified as of
African descent, who had class III or class IV HF. All were receiving stable
doses of standard therapy for HF (a variety of ACE inhibitors, beta-blockers,
digoxin, spironolactone, and diuretics). All had left ventricular ejection
fraction under 35%.
2. Randomized to:
1) A fixed dose of isosorbide/hydralazine given by mouth daily, or 2)
Placebo.
Dose = 37.5 mg hydralazine + 20 mg isosorbide
dinitrate three times daily. Dose could
be increased to a total of 225/120 mg daily depending on absence of
drug-induced side effects.
3. Primary end-point = a composite score
of death from any cause, a first hospitalization for HF, and change in
quality-of-life. Mean follow-up = 10 months.
RESULTS
1. The study was terminated early owing to a
significantly higher mortality in the placebo group.
(10% vs 6%; absolute difference = 4%; NNT
for 10 months = 25)
2. The mean composite score was
significantly better in the treatment group: absolute reduction in first
hospitalization for HF = 10%; and improvement in the quality-of-life score vs placebo of 2 points in a scale of 0
to 105.
3. Survival differences emerged at about 6
months, and widened thereafter.
4. Headache and dizziness were more common
in the isosorbide/hydralazine group. (I
could not find any record of withdrawals. RTJ)
DISCUSSION
1. Nitric oxide regulates cardiovascular
processes including myocardial hypertrophy, remodeling, vascular function,
inflammation, and thrombosis.
2. There is substantial evidence that
endothelial dysfunction and impaired bioavailability of nitric oxide occur in
patients with HF and contribute to the pathophysiology. “This study, however,
does not establish that these mechanisms explain the benefit of
isosorbide/hydralazine”.
3. Studies have shown significant
differences between blacks and whites in the response to pharmacotherapy of HF.
4. Isosorbide/hydralazine therapy in black
persons can slow the progression of HF.
CONCLUSION
The addition of a fixed dose of
isosorbide/hydralazine to standard therapy of HF was associated with increased
survival among blacks with advanced HF.
NEJM November 11, 2004;
351: 2049-57, Original investigation by the African-American Heart Failure
Trial
(A-heFT) Investigators, first author Anne L Taylor,
University of Minnesota, Minneapolis
=========================================================================
Some ask—Does Race Exist At All?
11-10 A RATIONAL BASIS FOR RACE
(This report
comments on the preceding study.)
Insights granted by the Human Genome
Project have helped dispel the deep-rooted myths about differences conferred by
race, and the health disparities attributed to such divisions.
Why are medical researchers now designing
drugs for specific groups? The fact is that humans are identical across 99.9%
of their genome. Humans are not divided along clear color-based lines which are
traditionally used in anthropological records. Some ask—Does race exist at all?
Some authorities suggest that, as
traditionally understood, race is not a biologically meaningful concept. Human
populations do exhibit genetic differences (due to different ancestries), and
also differences in disease susceptibility. The problem occurs when society and
the medical community generalizes these findings to the entire group. Prostate
cancer has a higher prevalence among African-American men. This does not mean
that all African-American men have similar risks for prostate cancer.
The connection between self-identified
race and genetic variation is very blurry. Culture, lifestyle, and social
stress may play a greater role in disparity.
Three ethical challenges in regard to genome
research remain:
1. Avoiding genetic determinism
2. Preventing genetic discrimination.
3. Ensuring equal access for all to the
benefits of genetic research.
Lancet November
20, 2004; 364: 1845-46 “World Report”,
commentary by David Lawrence
=====================================================================
Treatment to Reduce LV Mass May Follow A Course
Similar to Reductions in Cholesterol and BP.
11-11 LEFT VENTRICULAR HYPERTROPHY: The Next Silent Killer?
An increase in mass of the left
ventricular muscle is intimately associated with most chronic diseases of the
heart. Classically, left ventricular hypertrophy (LVH), which represents an extreme increase in left ventricular
mass, has been thought to represent a reaction to pressure or volume overload.
In the short run, an increase in left ventricular mass (LV mass) may be beneficial by allowing the heart to compensate for
increased wall stress and hemodynamic compromise. In the long run, it is
harmful.
Even mild increases in BP are associated
with increased LV mass.
LVH is a risk factor for premature death
and cardiovascular events. The Framingham study reported that LVH, as confirmed
by ECG, is associated with a mortality rate as high as that associated with a
Q-wave myocardial infarction. But, the
ECG may be a relative insensitive marker for LVH. Echocardiography detects
milder increases in LV mass which are prognostically important.
The LVH associated with hypertension
appears to be reversible. A long-term reduction in BP is associated with
reductions LV mass.
LVH is not often thought of as a
“standard” risk factor. Little data are available on the impact that reversing
LVH may have on outcomes.
Two articles in this issue of JAMA 1,2 report that reductions in left ventricular mass in
the setting of treatment for hypertension correlate with long-term
cardiovascular outcomes. The first trial, of hypertensive patients with LVH
documented by ECG criteria, reported the greater the treatment-decrease in ECG
markers of LVH, the greater the reduction in cardiovascular events. The second trial reported data obtained by
echocardiography. Over time, reductions in LV mass with treatment of
hypertension were associated with reduced risk of cardiovascular events. The
benefit of reductions in LV mass was independent of other potential
confounders.
“Active efforts to reduce left ventricular
mass may have important clinical benefits.”
Treatment to reduce LV mass may follow a course similar to reductions in
cholesterol and BP.
How should clinicians respond to these
observations? Patients being treated
for hypertension may be followed by serial ECG or, if conveniently available,
by echo. Failure of LV mass to respond might be an impetus for more aggressive
therapy, especially of those with borderline increase in BP. The studies . . .”Support the role of
evaluating of left ventricular hypertrophy at the time of hypertension
diagnosis and, at the very least, for considering changes in left ventricular
mass when tailoring long-term antihypertensive therapy.”
JAMA November 17, 2004;
2396-98 Editorial, first author
Julius M Gardin, St John Hospital and Medical Center, Detroit Mich.
1
“Regression of Electrocardiographic Left Ventricular Hypertrophy during
Antihypertensive Treatment and the Prediction of Major Cardiovascular Events” JAMA November
17, 2004; 292: 2343-49 first
author Peter M Okin, Cornell University Medical Center, New York.
2 “Prognostic
Significance of Left Ventricular Mass Change During Treatment of Hypertension” JAMA November
17, 2004; 292: 2350-56 first
author Richard B Devereux, Cornell Medical Center, New York
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FMS is the Second Most Common Disorder Observed by
Rheumatologists
11-12 MANAGEMENT OF FIBROMYALGIA SYNDROME
The diagnosis of the fibromyalgia syndrome
(FMS) is based on a history of
widespread chronic, bilateral upper body, lower body, and spine pain, and the
presence of excessive tenderness on applying pressure to 11 or more of 18
specific muscle-tendon sites. FMS has not been traced to any specific
structural or inflammatory cause.
This American College of Rheumatology
classification criteria for diagnosis of FMS provides a nearly 85% sensitivity
and specificity for differentiating FMS from other musculoskeletal pain.
FMS is the second most common disorder
observed by rheumatologists (after osteoarthritis). It has a prevalence of 2%
in the US. It is much more common in women. Chronic pain syndromes such as FMS
are defined by subjective symptoms. They lack unique pathophysiological
characteristics. No discrete boundary separates FMS from chronic fatigue
syndrome, irritable bowel syndrome, and chronic muscular headache. Mood
disturbances are comorbid with all. Abnormal pain processing (which has been
demonstrated by brain imaging) may be a common characteristic. Patients with
FMS have lowered mechanical and thermal pain thresholds, high pain ratings for
noxious stimuli, and altered temporal summation of pain stimuli.
Psychosocial factors contribute to the
clinical expression of FMS and related disorders.
This article summarizes the findings of a
report (based on a detailed literature search) commissioned by the American
Pain Society to provide evidence-based guidelines for the optimal management of
FMS. There are major limitations to the literature. Many treatment trials are
of short duration and lack masking. No
medical therapies have been specifically approved by the FDA.
Despite the chronicity and complexity of
FMS, there are interventions that may have clinical benefit in primary care
practice:
Medication:
1. Strong evidence for efficacy
Amitriptyline (Generic) a tricyclic antidepressant given at bedtime
2. Modest evidence for efficacy
Fluoxetine (Generic; Prozac; a SSRI. a selective serotonin reuptake inhibitor)
20-80 mg given at bedtime.
A number of drugs have been found
ineffective, including NSAIDs, corticosteroids, hypnotics.
Non-medical therapies:
1. Strong evidence for efficacy.
Cardiovascular exercise
Cognitive behavior therapy
Group education sessions
Combinations of above.
JAMA November 17, 2004;
292: 2388-95 Clinical Review, first author Don L Goldenberg, Tufts
University School of Medicine, Boston, Mass.
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