Cholesterol-lowering drugs reduce closing of heart arteries, study shows
FRIDAY, Aug. 15 (HealthDay News) -- Statins reduce the perils facing obese people after they have the bypass surgery that restores blood flow to an endangered heart, a study finds.
The study was done to help settle a running controversy about the ill effects of obesity in such cases, said Dr. Christina C. Wee, an associate professor of medicine at Harvard Medical School, co-director of research in the division of general medicine at Beth Israel Deaconess Hospital and lead author of a report in the Aug. 19 issue of the Journal of the American College of Cardiology.
"We know that obesity, per se, is a risk factor for developing heart disease," Wee said. "But once you develop it, is obesity more detrimental than not being overweight? There have been different studies with results going both ways."
To settle the issue, Wee and her colleagues studied the outcome of bypass surgery for 1,314 people in a controlled trial, using their body-mass index (BMI) as a measure of obesity. They found that a higher BMI was associated with a higher likelihood that arteries would become blocked again.
One arm of the trial compared progression of the condition in people given either low or high doses of a statin.
"What we found was somewhat surprising," Wee said. "With low-dose statin therapy, obesity was detrimental, with more blockage. What was unexpected was that with high doses of the statin, obesity did not have much of an effect at all."
While statins are prescribed to lower blood levels of LDL cholesterol, the effect seen in the study probably had a different cause, Wee said.
"We know that statins do more than lower cholesterol," she said. "They lower inflammation, and people who are obese have greater inflammation. There is a lot of evidence that inflammation in general is not good. Since a person who is obese has more of that going on, statins tend to protect."
The study offers a good argument for giving statins after bypass surgery, Wee said. "What we can say is that if you have heart disease, particularly if you had bypass surgery, you should be on a good dose of a statin," she said. The dosage described as "high" in the study now is regarded as standard, Wee added.
"If you are overweight or obese, you really should take your statin and be aggressive about it," she said. "You get much more benefit than for someone who is thinner."
Another paper in the same issue of the journal aimed at settling a controversy about the best way to measure the danger of obesity. A prevailing school of thought holds that measuring body-mass index is good enough. Anyone with a BMI of 30 or greater is obese.
Another theory is that not only the amount of fat, but also its distribution matters, with various ways of measuring fat in the waist area indicating more risk of cardiovascular disease and other major problems.
A team at Harvard Medical School tried both methods of obesity measurements used on the 16,332 men in the Physicians Health Study and the 32,700 women in the Women's Health Study, linking incidence of cardiovascular disease to the obesity described by the two methods.
The waist fat measurements "demonstrated the strongest association with cardiovascular disease and best model fit," the researchers reported. But they added that "cardiovascular disease risk increased linearly and significantly with higher levels of all indexes."
For more on statins and cholesterol, visit the U.S. Food and Drug Administration.
SOURCES: Christina C. Wee, M.D., co-director, research, Beth Israel Deaconess Hospital, division of general medicine, Boston; Aug. 19, 2008, Journal of the American College of Cardiology
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