Statins, Fibrates Thwart Diabetic Peripheral Neuropathy

Internal Medicine World Report, October 2007, Volume 0, Issue 0

Off-Label Use Shows Significant Benefits

Off-Label Use Shows Significant Benefits

By Jill Stein

CHICAGO—Treatment with either a statin or a fibrate appears to prevent the onset of diabetic peripheral neuropathy, according to preliminary results reported at the American Diabetes Association annual meeting.

Timothy M. Davis, MD, professor of medicine at the University of Western Australia in Perth, reported the results of a new study showing that statins decreased the likelihood of peripheral neuropathy in patients with type 2 diabetes by 35%, and fibrates reduced the risk by 48%.

"Our study was not an interventional trial but rather observational, which limits our interpretation of the findings," Dr Davis cautioned. "However, our findings do seem to support the use of these 2 classes of drugs outside of their conventional uses."

Commenting on the study, Aaron Vinik, MD, director of the Strelitz Diabetes Institutes at Eastern Virginia Medical School in Norfolk, said that these findings are extremely important, all the more so because no current medications are specifically designed to prevent or treat the progression to peripheral neuropathy"*"an extremely common condition in patients with diabetes that has devastating sequelae.

"Medications are available to treat the pain but not the underlying disease," he said. "Peripheral neuropathy occurs in about half of all diabetic patients, and the condition results in about 90,000 amputations in the United States each year," said Dr Vinik.

The data for the study come from a cohort of patients with type 2 diabetes enrolled in the Fremantle Diabetes Study (FDS) between 1993 and 1996. The FDS was a prospective observational study of the care, metabolic control, and complications in diabetic patients recruited from a community of 120,097 people in Western Australia.

In the new study, Dr Davis and colleagues assessed the relationship between lipid-lowering therapy and the prevalence and incidence of peripheral neuropathy. The Michigan Neuropathy Screening Instrument, a widely validated screening tool, was used to establish the presence of peripheral neuropathy.

At the time of enrollment, the 1294 participants with type 2 diabetes had a mean age of 64.1 years; their diabetes had been diagnosed a median of 4 years before entering the study.

Nearly 33% had peripheral neuropathy. Overall, 3.5% of the patients were being treated with fibrates, and 6.8% with statins. The cohort was considered to be representative of patients with type 2 diabetes.

The analysis showed that older age, longer diabetes duration, central adiposity, increasing height, higher fasting plasma glucose, higher systolic blood pressure, higher urinary albumin:creatinine ratio, and indigenous racial background were all independently associated with prevalent peripheral neuropathy at baseline.

The use of fibrate therapy, however, was associated with a 70% reduction in neuropathy prevalence.

Dr Davis also described the results in a subgroup of 531 individuals who attended 6 comprehensive annual health assessments during 5 years of follow-up. Fibrate and statin use increased to 10.4% and 36.5%, respectively, during that time frame.

An analysis aimed at identifying independent predictors of neuropathy onset showed risk reductions of 48% in fibrate-treated and 35% in patients treated with statins.

The statins used in the trial were atorvastatin (Lipitor), pravastatin (Pravachol), and simvastatin (Zocor). Fibrates included gemfibrozil (Lopid) and fenofibrate (Tricor). Dr Davis postulates that the improvements seen with the 2 types of drugs probably represent a class effect.