CHOLESTEROL WATCH

Calcium + Vitamin D = Improved Cholesterol Levels

Canadian researchers have found that a combination of calciumand vitamin D during weight loss in overweight and obesewomen could help improve their cholesterol levels. Calcium,either from dairy foods or supplements, has been linked withweight loss in various populations. A study published in 2006stated that calcium supplements could help women loseweight. The recent study showed that calcium plus vitamin Dalso aids in lowering cholesterol levels. The results of the studywere published in the January 2007 issue of the AmericanJournal of Clinical Nutrition.

Researchers at Laval University, Ste-Foy, Canada, studied 63women who were of healthy weight, overweight, or obese andassigned them to either a daily supplement of calcium plus vitaminD (600 mg/200 international units) or a placebo for 15weeks. Both groups took part in a weight-loss program thatrestricted them to 700 kcal per day. At the end of the study,those who had taken the supplement showed significantimprovements in both high-density lipoprotein cholesterol andlow-density lipoprotein cholesterol, independent of changes infat mass and waist circumference. Researchers said that anumber of mechanisms may be responsible for the apparenteffects of the supplements, including the role of calcium tointerfere with fat absorption in the gut, boosting the body's abilityto burn fat, or potentially having a satiety role.

Researchers Discover Arterial Plaque Rupture Process

Scientists at Columbia UniversityMedical Center (New York, NY) haveidentified an important molecularprocess that can cause plaque rupturein patients with atherosclerosis. Thefindings could help scientists developtherapies that would prevent plaqueruptures, which can cause clots thatcan block blood flow and cause heartattacks and strokes. The findings werepublished in the December 26, 2006,issue of the journal Proceedings of theNational Academy of Sciences.

The study found that macrophages—white blood cells that accumulate in thecholesterol-laden plaques along arterywalls—die when 2 receptors on thecell's surface are activated at the sametime. When these dead macrophagespile up, they become a significant triggerto plaque rupture. This findingcomes with the promise of finding alternativemethods of preventing plaquerupture outside of solely increasing levelsof high-density lipoproteins withmedication. "It's particularly importantfor us to consider alternative strategiesand to understand the process behindthe rupture of plaques," said researchers.

Niacin Effective at Raising HDL

Studies have shown that niacin, in its therapeutic formof nicotinic acid, can increase high-density lipoprotein levelsby as much as 35%, as well as reducing levels of triglyceridesby as much as 50%, when taken in high doses,usually about 2000 mg/day.

The Coronary Drug Project, a landmark study of 8341men, aged 30 to 64 years, who had experienced heartattacks, found that niacin was the only treatment out of 5that were tested that prevented second heart attacks.Men who took niacin had a 26% reduction in heart attacksand a 27% reduction in strokes, compared with men onplacebos. Fifteen years later, the mortality rate among themen who took niacin was 11% lower than in those whotook placebos. The researchers suggested that addingniacin to low-density lipoprotein-lowering statins canslow the progress of cardiovascular disease and reducethe risk of heart attack and other adverse outcomes by upto 35%.

Ideal Cholesterol Levels Challenged

A review paper published in the October 3, 2006, issue of theAnnals of Internal Medicine has raised questions about theaggressive cholesterol-lowering recommendations made 2 yearsago by the National Cholesterol Education Program. The panelurged patients at risk for heart disease to sharply reduce theirlow-density lipoprotein (LDL) levels and to attempt to reach verylow levels. The authors of the paper argued that there is notenough solid evidence to support the target numbers set forth bythe panel.

Until 2004, an LDL level of <130 mg/dL was considered to besufficiently low. The updated guidelines, however, recommendedthat high-risk patients reduce their LDL levels to <100 mg/dL,while patients at very high risk were encouraged to lower theirlevels to <70 mg/dL. The authors examined all the studies thatassessed the relationship between LDL and cardiovascular outcomesin patients with LDL <130 mg/dL and were unable to identifystudies that provided evidence that reaching a certain LDL targetlevel was important by itself, apart from other factors.