Jewish World Review Nov. 15, 2002 / 10 Kislev, 5763
By Robert A. Wascher, M.D., F.A.C.S.
http://www.NewsAndOpinion.com |
At the present time, the most commonly used "biomarker" for increased
cardiovascular disease risk is the blood cholesterol profile. Levels of
high-density lipoprotein (HDL, the "good cholesterol") and low-density
lipoprotein (LDL, the "bad cholesterol") in the blood have been shown to
correlate with overall risk of cardiovascular disease.
High levels of LDL
have been linked with an increase in the rate and severity of arterial
atherosclerosis (narrowing of the arteries due to build-up of fatty
plaques). As I have discussed in previous columns, however, the modern view
of heart attack and stroke physiology now encompasses more than just the
mere development of arterial plaques. Indeed, there is a great deal of
evidence that inflammation of these atherosclerotic plaques, and the
subsequent formation of blood clots on the surface of these plaques, are
critical events that lead to most strokes and heart attacks secondary to
atherosclerosis. A crucial link in this inflammatory process appears to be
a substance known as C-reactive protein (CRP). High levels of CRP have been
conclusively shown to be associated with a significantly increased risk of
cardiovascular disease events, including stroke and heart attack.
A new study in the current issue of the New England Journal of Medicine
further advances our understanding of the implications of elevated CRP
levels in the blood with respect to the risk of cardiovascular disease
events. This is the first study to simultaneously measure both LDL and CRP
levels in the blood of a large number of healthy adults, and to follow these
study volunteers for a long period of time to look at the incidence of
subsequent cardiovascular events. A total of 27,949 healthy American women
without known cardiovascular disease entered the study, at which time LDL
and CRP blood levels were measured. The study participants were then
followed for an average of eight years. The incidences of heart attack,
severe heart ischemia requiring invasive treatment, and stroke secondary to
atherosclerosis were then observed. The value of the LDL and CRP tests as
predictors of these cardiovascular events was then analyzed.
Following adjustments for the contributing effects of blood pressure, age,
smoking status, presence or absence of diabetes, and other cardiovascular
disease risk factors, the authors found that elevated levels of both LDL
and CRP correlated significantly with the risk of cardiovascular disease
events. Moreover, screening for both biomarkers appeared to provide more
accurate prognostic information than either test alone. When used alone,
the CRP test also appeared to correlate more closely with already
established cardiovascular disease risk factors than did the LDL test by
itself. Among the study volunteers, the women with the highest blood levels
of CRP had more than twice the risk of experiencing a cardiovascular disease
event than did the women with the lowest CRP levels.
The results of this study suggest that cardiovascular disease prevention
strategies should target not only LDL and total cholesterol levels in the
blood, but also CRP levels. The study's authors concluded that CRP may be a
more accurate prognostic factor for the development and progression of
cardiovascular disease than the currently used LDL assay. The combined use
of both CRP and LDL tests may also enhance our ability to predict which
patients are at greatest risk of experiencing a heart attack or stroke due
to atherosclerotic arterial disease. The ability of anti-inflammatory
medications such as aspirin, and the statin class of drugs, to reduce CRP
levels may explain, at least in part, their well known cardiovascular
disease prevention effects. At the present time, however, the evidence that
reducing high CRP levels in the blood directly translates into a reduced
risk of cardiovascular events is lacking. Such a study would, of course, be
a logical next step.
GROWTH HORMONE & SEX STEROID SUPPLEMENTS & THE ELDERLY
In men, testosterone levels also play a key role in maintaining
lean body muscle mass and, like GH, levels of testosterone in the blood fall
significantly during mid-life. In this week's Journal of the American
Medical Association is an interesting study that looks at the effects of
human GH on strength and endurance in older men and women. The study looked
at the effects of the sex hormones (SH) progesterone, estradiol and
testosterone as well. A total of 57 healthy men and 74 women, aged 65 to 88
years, participated in the study for a duration of six years. The women
received GH and the female SH progesterone and estradiol. The men received
GH and testosterone supplements. Some of the patients received GH alone, SH
alone, or placebo (sugar pills) only. Lean body mass, fat mass, muscle
strength, oxygen consumption during exercise and adverse health effects were
evaluated.
Among the women, lean body mass increased significantly while fat mass
significantly decreased with GH and SH and, to a slightly lesser extent,
with GH alone. Muscle strength did not increase significantly with GH plus
SH, or with GH alone, among the women. Oxygen consumption with exercise was
also not significantly improved in the women taking GH and SH, or with GH
alone. The women also tended to experience an increase in edema (swelling
of the arms and legs) with GH, and with GH plus SH.
Among the men, lean body mass increased with GH, and even more dramatically
with GH plus SH, while fat mass decreased among the men taking GH, with or
without SH. The men's strength, unlike the women's, appeared to be
marginally increased by the combination of GH and SH. Carpal tunnel
syndrome was more common in the men taking GH. Diabetes and glucose
intolerance was also more common among the men receiving GH.
This study suggests that the benefits of growth hormone in elderly patients
are moderate in terms of improving lean body mass (i.e., muscle), while the
adverse effects of such treatment may be quite significant in this age
group. Only marginal improvements in muscle strength and improved oxygen
uptake occurred with GH plus SH, and then only in the men. This study,
though encompassing a rather small number of participants, would appear to
suggest that the benefits of GH supplementation, with or without SH
supplementation, are modest, while the side effects are significant. Thus,
based upon this study anyway, it may be premature to recommend such
supplements to overcome the loss of lean body mass and endurance that comes
with aging. On the brighter side, however, weight training in older adults
has been conclusively shown to increase lean body muscle mass while reducing
body fat levels. As a side benefit of strength training among the elderly,
the risk of diabetes is reduced, along with the incidence of high blood
pressure, heart disease and other life-threatening age-related maladies!
THE EFFECTS OF DIET & EXERCISE ON BLOOD PRESSURE & HEALTH
At the end of only three weeks, the study confirmed that the diet and
exercise program resulted in a significant decrease in blood pressure, LDL
and insulin levels in the men. The level of oxidative metabolic stress (due
to the production of cell-damaging free radicals), which has been linked to
the development of atherosclerosis, also declined after only three weeks on
the program. These beneficial changes were present even among those study
volunteers who did not lose any significant weight or fat mass during this
brief period of diet modification and exercise. These findings should
encourage even those of us who are allergic to exercise and good dietary
habits to exercise and watch what we eat. This study confirms that even
very short-term modifications in diet and exercise levels can reap very
significant health rewards in return!
JWR contributor Dr. Robert A. Wascher is a senior research fellow in molecular & surgical oncology at
the John Wayne Cancer Institute in Santa Monica, CA.
Comment by clicking here.
C-Reactive Protein & Cardiovascular Disease Risk
There have been several studies published recently that have touted the
"rejuvenating effects" of growth hormone supplements in older adults.
Growth hormone (GH) levels rapidly decline following adolescence, and again
in middle age. This progressive decline in GH levels is thought to play an
important role in the loss of lean muscle mass that begins to develop in
middle age.
While we're on the topic of the manifold benefits of exercise, a new study
in the current issue of the journal Circulation takes a look at some of the
effects of even short-term dieting and exercise on blood pressure and
overall health. The study looked at the relatively short-term health
effects of a rigorous diet and exercise program on 11 adult men. The study
volunteers were placed on a low-fat high-fiber diet combined with 45-60
minutes per day of aerobic exercise for three weeks. Blood was drawn at the
beginning and the end of the study, and tested for cholesterol (HDL and
LDL), insulin, and glucose levels. Blood pressure readings were regularly
recorded throughout the study as well.
11/08/02: More Good News About Statin Drugs; Hormone replacement Therapy (HRT) & Alzheimer's Disease; A Role for Antibiotics in the Treatment of Vascular Disease?; more
11/01/02: Digoxin & gender; driving & degenerative disc disease; Coenzyme Q10 & Parkinson's Disease; Ginseng & erections; Viagra & stroke
10/25/02: Aspirin & coronary artery bypass surgery; glucosamine sulfate & progression of knee arthritis; hospital nurse staffing & patient mortality
10/18/02: Motor Vehicle Exhaust Pollution & Mortality; CT Scans, C-Reactive Protein & Heart Disease; Antiperspirant Use & the Risk of Breast Cancer; Atomic Bomb Radiation Exposure Update; more
10/04/02: Antioxidants & the Risk of Stomach Cancer; Best Way to Diagnose Appendicitis?; Coronary Artery Disease: Stent or Surgery?
09/27/02: Breast Feeding & the Risk of Asthma; HMOs & Quality of Care Scores; Red Wine & Vascular Disease
09/20/02: Dietary Folate & the Risk of Colorectal Cancer; Risks Associated with Smoking after Heart Attacks; BRCA1 Gene Mutation & the Risk of Breast & Non-breast Cancers; Breast Tissue Density & Inheritance
09/13/02: Dairy Products, Calcium, Vitamin D & the Risk of Breast Cancer; Efficacy of Nonprescription Smoking Cessation Aids; A Nutty Approach to Heart Disease Prevention; Update on Prostate Cancer
09/06/02: C-Reactive Protein & Estrogen Replacement Therapy; Walking Women & Cardiovascular Disease; Physical Activity Among Teenaged Girls
08/30/02: Babbling babies & brain function; homocysteine levels, vitamins & coronary artery disease; St. John's Wort & chemotherapy
08/16/02: A New Weapon Against Anthrax?; cataracts & motor vehicle accidents; gingko biloba takes a hit; air pollution & heart function during exercise; breast cancer genes & the estimated risk of breast cancer
08/09/02: Botulinum Toxin & Post-Stroke Spasticity; Intestinal Hormone Kills Appetite; Bone Marrow Cells Improve Blood Flow in Vascular Disease; Effectiveness of Restraining Orders on Domestic Violence
08/02/02: Mammography Saves Lives!; Obesity & the Risk of Heart Failure; High Sugar Diets & the Risk of Colon Cancer; Abuse During Childhood & Possible Effects of Genes on Antisocial Behaviors
07/26/02: Cancer: Nature vs. Nurture; Cardiorespiratory Fitness & Inflammation; Kidney Transplants from Cadaver Donors; Aircraft Cabin Air Recirculation & the Common Cold
07/19/02: PCBs & the Gender of Babies; Breastfeeding & the Risk of Breast Cancer; More Bad News About Hormone replacement Therapy
07/12/02: A cancer surgeon's perspective on hormone replacement therapy
07/08/02: Hormone replacement therapy & the risk of disease; more good news about statins; antioxidant vitamins & disease prevention; more
06/28/02: Antioxidants & the Risk of Alzheimer's Disease; Effects of Exercise on the Hearts of Patients with Mild Hypertension; Statins reduce cardiac events following angioplasty; more
06/21/02: Sex & violence and Advertising: Do Advertisers Get What they Pay For?; Don't Drink the Water (or the Salsa Either!); Vasectomy & Prostate Cancer Risk; Update on Smoking & Disease
06/14/02: Young Men, Obesity & Heart Disease; Breastfeeding & Obesity; Irritable Bowel Syndrome & rectal pain threshold; more data on cox-2 inhibitors & cancer; more
06/07/02: New coronary artery stent reduces risk of restenosis; possible cause of Parkinson's Disease identified; more
05/31/02: New biological insights into obesity & weight loss; broccoli kills cancer-causing stomach bug; anti-inflammatory drugs and the risk of heart attack
05/24/02: Molecular detection of tumor cells in the blood & prognosis; Cox-2 & breast/lung cancers; BRCA2 gene mutations & the risk of breast cancer; breast density & the risk of breast cancer
05/19/02: Moderate alcohol intake and blood sugar levels; more good news for tea drinkers; blood potassium levels & the risk of cardiovascular disease; ethnic differences in diabetic complications
05/10/02: Tea drinkers and the risk of death following heart attack; duration of breastfeeding & adult intelligence; abdominal aortic aneurysms: surgery or observation?
05/03/02: Risk of adverse drug reactions from newly released medications; preoperative beta-blockers may reduce heart bypass deaths; shape-shifting plastics may alter surgical practice; weight loss
supplement may cause liver damage
04/26/02: Angry young men & risk of premature cardiovascular disease; stay-at-home dads & risk of
cardiovascular disease; more on the effects of statins; dairy consumption and the risk of
pre-diabetes; smallpox vaccine: good to the last drop?
04/19/02: Change your sex by drinking water?; Anti-inflammatory RXs may reduce growth of breast cancer cells; radiation treatment reduces repeat narrowing of bypass grafts
04/05/02: Fish & Omega-3 fatty acid consumption and cardiac health; news briefs
04/05/02: Can coffee reduce your risk of tooth decay?; exercise & blood pressure; a single high-fat meal reduces coronary artery function
04/01/02: Pre-diabetes: a newly defined category of
health risk; teen television viewing and subsequent
aggressive behavior; the benefits of strength training
in the elderly; more ...
03/22/02: Bacteria, antibiotics & heart disease; mammograms: the debate continues; calcium & the risk of colon cancer ... and more
03/15/02: Mammography debate continues; statins & fracture risk; physical fitness & the risk of death; other intriguing findings
03/08/02: Blows to the chest & sudden cardiac death; air quality & the risk of lung cancer; tomatoes and your prostate
03/01/02: Diet & the risk of ovarian cancer; lifetime risk of developing high blood pressure; Osteoporosis prevention with a once-a-year injection?
02/26/02: The continuing controversy regarding screening mammography
02/22/02: Lowering body temperature after heart attack improves outcome; A silver lining for the chronically sleep-deprived?
02/15/02: Hormone replacement therapy & the risk of breast cancer; use it or lose it: Alzheimer's disease
& cognitive stimulation; stress, divorce & death; child daycare, infections & parental guilt
02/08/02: Possible breakthrough in early cancer diagnosis; mammography: the controversy continues; CPR techniques revisited
02/01/02: Antibiotics in livestock feed & human disease; genetic detection of early colon cancer in the stool; genetic analysis of breast cancers may help decide treatment
01/25/02: Drug increases lifespan (if you're a fly...); workplace attitudes and smoking cessation; effects
of inadequate sleep on surgeons
01/18/02: Lifelong effects of premature birth; smokers under the knife; aspirin and cardiovascular health
01/11/02: Estrogen levels in the blood & breast cancer risk; Heart attack: sex and survival; dangerous lettuce invaders
01/09/02: Cancer & aging: Two sides of the same coin?
01/04/02: Vitamin a & the risk of hip fracture in postmenopausal women; ovarian cancer risk and oral contraceptives
12/28/01:
Magnetic Resonance Imaging (MRI) detects
coronary artery disease; new development in
obesity research; adverse childhood experiences &
the risk of suicide attempts
12/21/01: Vaccination of children controls hepatitis a in the community; a possible cure for sickle cell disease; leptin and the risk of heart attacks
12/14/01: Chernobyl and the Risk of Thyroid Cancer in hildren; children & obesity; gastroesophageal reflux disease update
12/07/01: Update on school shootings; new implantable heart-assist device approved for further evaluation; prevention of fungal infections in pre-term babies
11/30/01: Flu vaccination in asthmatics; low-tar cigarettes are not less harmful; beans and your heart
11/21/01: Modified smallpox vaccine may reduce risk of cervical cancer; New approach to breast cancer diagnosis; New non-invasive prenatal diagnostic test for down's syndrome
11/16/01: Cholesterol-lowering drugs reduce risk of heart attack; supplemental radiation therapy reduces risk of breast cancer recurrence; brains of women may answer age-old questions
11/09/01: Bio-warfare (redux); my gray matter is bigger than yours; mad elk disease?
11/02/01: Making sense of bio-warfare
10/26/01: The impact of mammography on deaths due to breast cancer; diet & exercise may slow cancer cell growth; antidepressants and the risk of heart disease
10/19/01: New insights into autism; the wiley appendix
10/12/01: More bad news about obesity links to other diseases…Hey dad, can I borrow the car keys?
10/05/01: California leads nation in reduction of tobacco-related disease; exercise as an antidepressant?
09/25/01: Advances in the detection of breast cancer; primary care physician awareness of peripheral arterial disease; arsenic in the water
09/17/01: In perspective
09/12/01: Genes may hold secret to long life; men and women: cognitive function in the elderly; physical activity, obesity and the risk of pancreatic cancer
09/05/01: English milk cows prefer Beethoven and Simon & Garfunkel over
Bananarama; new prostate cancer prevention study: looking for a few good men; exercise & diet can help prevent diabetes
08/28/01: Arthritis drugs may be linked with increased risk of heart disease; errors in blood clotting tests can be fatal; infant soy formula not associated with reproductive side effects