Policosanol Did Not Improve Lipids
The supplement policosanol, which is touted for its lipid-lowering effects and is popular worldwide, did not lower lipids appreciably in a multicenter, randomized clinical trial, reported Dr. Heiner K. Berthold and associates at the University of Cologne, Germany.
Dozens of studies have reported that policosanol, a mixture of long-chain primary alcohols derived primarily from sugar cane wax, lowers LDL cholesterol as effectively as do statins, without side effects. But “virtually all of the published scientific literature supporting the beneficial effects of policosanol on lipids has been authored by a single research group from Cuba,” they wrote.
Almost all of these studies were funded by “a commercial enterprise founded by the Center of Natural Products” in Cuba to market Cuban policosanol. “Our trial is the first study to investigate sugar cane-derived policosanol independently from [this] research group but still using Cuban policosanol,” they said (JAMA 2006;295: 2262–9).
Dr. Berthold and colleagues randomly assigned 129 hypercholesterolemic patients at 14 clinical centers in Germany to one of five groups, to receive 10, 20, 40, or 80 mg of policosanol or placebo daily for 12 weeks. The usual recommended doses are 10 and 20 mg/d. All the patients were white; their mean age was 56 years, and their mean LDL cholesterol level was 187 mg/dL at baseline.
Policosanol did not decrease LDL cholesterol at any dose, beyond the small (less than 10%) reduction noted with placebo. Policosanol also had no appreciable effect on total cholesterol, HDL cholesterol, very-low-density lipoprotein cholesterol, triglycerides, or lipoprotein (a).
“A considerable health-food-store and Internet market has extended the development of nonprescription policosanol, and worldwide sales are constantly increasing,” they noted, calling for other independent studies of policosanol's purported efficacy to counterbalance the vast body of available positive trials.
Diabetics Benefit From Statins
Lipid-lowering agents, particularly statins, significantly reduce cardiovascular risk in people with diabetes, to the extent that these patients may benefit from the drugs even more than nondiabetics do, said Dr. Joào Costa of the University of Lisbon and associates.
They conducted a metaanalysis of 12 large studies that addressed lipid-lowering treatments and also included diabetic patients in all treatment arms.
Lipid-lowering drugs were equally effective in diabetic and nondiabetic patients for primary prevention. The use of statins or gemfibrozil reduced the risk of a first major coronary event by 21% in diabetic patients and by 23% in nondiabetics. The results were similar for secondary prevention, except that diabetic patients benefited more than did nondiabetics.
The use of statins or gemfibrozil reduced the risk of coronary artery disease death, nonfatal MI, revascularization procedures, and stroke to a greater degree in diabetic patients than it did in nondiabetic patients.
The magnitude of change in blood lipids for diabetic patients was comparable to that for nondiabetics. “Most trials showed a decrease of 15%–20% in total cholesterol and increases of 5%–7.5% in HDL cholesterol,” the investigators said (BMJ 2006 April 3 [Epub doi:10.1136/bmj.38793.468449.AE]).
“Our metaanalysis clearly confirms that reduction of LDL cholesterol concentrations results in an important decrease in major coronary events in diabetic patients and shows similar relative risk reductions and odds ratios for … diabetic and nondiabetic patients … in primary and secondary prevention. However, the absolute risk difference was three times higher in secondary prevention, reflecting the higher baseline cardiovascular risk of [diabetic] patients,” they noted. Despite the well-documented benefits of statins, “they are not being optimally used in patients at higher risk—the ones most likely to benefit.”
A recent cohort study of nearly 400,000 patients over age 65 showed that only 19% of those with a history of diabetes or cardiovascular disease were prescribed statins, Dr. Costa and associates added.
“Our results support the use of statins not only for secondary prevention but also for primary prevention in [diabetic] patients,” they said.
Statins May Decrease Cataract Risk
Statins, particularly simvastatin, appear to lower the risk of nuclear cataracts, the most common type of age-related cataracts, results of a large, prospective study suggest.
Both oxidative stress and inflammation have been posited as contributors to age-related cataracts, especially nuclear cataracts, and statin therapy is known to counter both effects, wrote study investigators Dr. Barbara E. K. Klein and her associates at the University of Wisconsin, Madison.
The investigators used data from the Beaver Dam Eye Study, a longitudinal community survey of eye health in which subjects have been examined every 5 years since 1987–1988, to assess whether the use of statins for cardiovascular indications affected the development of cataracts.