German and Swiss researchers have found that high-density lipoprotein, or HDL-so-called “good” cholesterol-does not protect blood vessels in people with type 2 diabetes as well as it does in people who don’t have the disease. However, their follow-up experiment, which added doses of extended-release niacin, shows that HDL’s efficacy in type 2s might be sharply increased simply by the addition of a daily niacin pill.
HDL, which carries “bad” cholesterol-low-density lipoprotein-away from arteries, is thought to reduce cardiovascular disease by thwarting the build-up of plaque and removing chemicals that damage arterial walls and reduce their flexibility. Medical scientists consider high levels of HDL to be one indicator of a lower risk of heart disease.
Researchers at the University Hospital Zurich in Switzerland and the Medical School of Hanover in Germany studied 10 non-diabetic patients and 33 people with type 2 diabetes or metabolic syndrome to see how HDL affected the health of their blood vessels. (The diabetes patients were already taking cholesterol-lowering medication and had low levels of HDL as well.) The scientists found that the ability of HDL to protect blood vessels in type 2s was “substantially impaired.”
To see if they could increase HDL levels and functionality in the people with diabetes, the researchers split the type 2s into two groups, one taking a placebo and the other taking 1,500 mg daily of extended-release niacin. Previous studies had shown that niacin increases HDL and lowers other fats in the blood.
After three months, the type 2s taking the niacin had increased HDL levels and improved vascular function. The placebo group showed no similar increases or improvements.
Given that the study group was extremely small, the Swiss and German researchers will not recommend extended-release niacin as a routine treatment for some type 2s until a much larger, more formal study can confirm their findings.
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