Now there's preliminary evidence that so-called "lipid-lowering drugs" might protect people with diabetes from peripheral neuropathy.
The drug classes are statins (Lipitor, Lescol, Mevacor, Pravachol, Crestor, and Zocor) and fibrates (Lopid, Gemcor, and Tricor). These drugs are often prescribed to people with diabetes to lower cholesterol and blood fats.
Timothy Davis, MD, PhD, of the University of Western Australia, and colleagues tracked 400 people with type 2 diabetes who, at the time the study began, had no sign of peripheral neuropathy. Over five years, 63% of these patients -- about 12% a year -- developed the condition.
Yet those who started lipid-lowering therapy with statins (mostly Zocor, Pravachol, and Lipitor) or fibrates (mostly Lopid or Gemcor) were less likely to suffer peripheral neuropathy.
"Lipid lowering does affect neuropathy," Davis tells WebMD. "The protection was 35% for statins and 48% for fibrates -- statistically the same protection -- and these effects were independent of blood sugar control, height, age, other things associated with neuropathy."
Davis presented the findings at the American Diabetes Association's 67th Annual Scientific Sessions, held June 22-26 in Chicago.
The findings, Davis notes, come from what scientists call an observational study. That is, the researchers simply observed what happened and used statistical tests to tease out possible causes. Only a clinical trial, in which patient differences are carefully controlled -- and in which drugs are tested against inactive placebos -- can prove whether a drug actually has a specific effect.
All the same, Davis is convinced these effects are real. And he suggests that the two different types of drugs may have different mechanisms of action.
"If you took both drugs, which is increasingly done for greater lipid lowering, the benefit may be additive. But that is a conjecture," Davis says.
Peripheral neuropathy expert Aaron I. Vinik, MD, PhD, director of the Strelitz Diabetes Research Institute in Norfolk, Va., says the Davis team's findings may help answer questions that have been increasingly perplexing diabetes researchers.
"When I saw Dr. Davis's study I was very excited," Vinik said at a news conference. "This may change the way we think about peripheral neuropathy -- and maybe even lead to a treatment."
Vinik notes that only two drugs are approved to treat peripheral neuropathy in diabetes -- and both drugs only help with the pain.
And there's another interesting thing about the Davis study, Vinik says.
"There are many reports about statins producing neuropathy, yet this study says maybe they are good for you," he says.