Good cholesterol may protect diabetic's kidneys

Higher levels of high-density lipoproteins (HDL), the "good" cholesterol, are associated with a lower risk of protein in the urine, a sign of kidney disease, in patients with long-standing type 1 diabetes, researchers from Chicago report.

Dr. Mark E. Molitch from Northwestern University and colleagues analyzed the cholesterol profiles of 107 patients who had type 1 diabetes, also known as juvenile diabetes, for at least 20 years. Forty-two of them had protein in the urine, also known as albuminuria, and 65 did not.

Total cholesterol, low-density lipoprotein (LDL) levels (the "bad" cholesterol) and triglyceride levels were similar in those with and without albuminuria. In contrast, HDL cholesterol levels were significantly lower in patients with albuminuria compared with those without albuminuria.

When the patients' age and sex were considered in the analyses, a 10-mg/dL increase in HDL cholesterol was associated with a 30-percent lower risk of albuminuria, according to the report in the latest issue of Diabetes Care.

When the patients' age, sex, diabetes duration, and degree of diabetes control were considered, the odds of having albuminuria were halved for every 21-mg/dL increase in HDL.

"I have long been looking for the reason why a number of patients with type 1 diabetes seem to have few complications despite suboptimal control. This may be one reason," Molitch told Reuters Health. "This is a very preliminary report that needs confirmation in larger numbers of patients," he emphasized.

Whether the higher HDL is protective or whether it reflects some other mechanism is unknown," Molitch added. "The data reported show only an association and not cause-and-effect and would not support the concept that patients should try to raise their HDL levels to prevent diabetic kidney disease."

SOURCE: Diabetes Care, January 2006.