Update on Cholesterol
It's always reassuring that the top clinical research centers in the nation are continually working to update their treatment guidelines. In November 2013, the American College of Cardiology (ACC), along with the American Heart Association (AHA) and the Center for Disease Control (CDC), updated their clinical practice guidelines for cardiovascular disease. How do their findings affect our knowledge of disease prevention and evaluation of cholesterol levels?
We've known a healthy lifestyle is essential: the recommendation is to sustain an active lifestyle (at least 30 minutes of walking or exercise daily) and maintain a normal weight, generally a body mass index of between 22 and 25. Research participants with BMI of between 26 and 28, although technically overweight, also did quite well in the heart studies so long as they were physically active. While being overweight is not ideal, the notion of "fit over fat" is prevalent. Fitness can be more important than build, and a normal build in the absence of any physical activity can be a risk factor.
All the committees are strong advocates for the use of statin drugs to lower cholesterol levels. While a common joke is that cardiologists would like statins added to the water supply, the "2013 Report on Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Disease in Adults" was clear that high intensity statins appear to reduce cardiovascular risk in primary and secondary prevention populations across all ranges of triglyceride levels. Omega-3 fatty acids and fibrate drugs were considered useful adjuncts but now statin drugs alone can simplify therapy.
Most of the clinical trial data is based on total cholesterol and ratio of total cholesterol to HDL (the "good" fraction). As a result, newer drugs thought to raise good cholesterol were studied relative to mortality. Although HDL is still a good indicator for increased atherosclerotic risk, the panel found that the drug of choice for those with increased cardiovascular risk and low HDL levels was in fact statins. None of the trial data suggested the use of other adjuncts for therapy.
So what are acceptable numbers and who should be treated? Those with clinical atherosclerotic heart disease, LDL ("bad" cholesterol) over 190, those with diabetes, and those with calculated scores by the American Heart Association over 7.5% should be treated. While accepted thinking was cholesterol/HDL ratios should be under 6.5-8, and total cholesterol less than 240, now the preferred criteria is cholesterol under 190 and ratio under 4.5. In clinical practice, if other diseases associated with cardiovascular disease (like diabetes, heart attack, or kidney failure, for example) are present, some guidelines prefer total cholesterol below 130 and LDL (bad cholesterol) measurements under 70. Again, statins are the treatment of choice.
Statins (some of the more common brand names are Lipitor, Crestor and Zocor, among others) have been found to significantly decrease cholesterol levels. In moderate doses, they lower total cholesterol between 30% and 40%, and in higher dosages, up to 50%. In addition, statins have been shown to modestly increase good cholesterol (HDL). While not indicated in those with kidney disease, the incidence of two major side effects (liver enzyme abnormalities and muscle disorders (myopathy)), are quite low. However, it is necessary to monitor these potential side effects by following up with your doctor.
Of course, the presence of any other additional factors, such as high blood pressure, obesity, an abnormal EKG, or diabetes can increase risk for coronary heart disease. It makes decreasing high or even high-normal cholesterol even more important to evaluate increased risk and reduce mortality. Lowered levels equate to lower overall mortality.
Authored by Dr. Bob Goldstone, M.D.
The information contained on this page is not intended to provide medical advice, which should be obtained directly from your physician.