The effects of long-term oral benfotiamine supplementation on peripheral nerve function and inflammatory markers in patients with type 1 diabetes: a 24-month, double-blind, randomized, placebo-controlled trial

OBJECTIVE

To study the effects of long-term oral benfotiamine supplementation on peripheral nerve function and soluble inflammatory markers in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

The study randomly assigned 67 patients with type 1 diabetes to receive 24-month benfotiamine (300 mg/day) or placebo supplementation. Peripheral nerve function and levels of soluble inflammatory variables were assessed at baseline and at 24 months.

RESULTS

Fifty-nine patients completed the study. Marked increases in whole-blood concentrations of thiamine and thiamine diphosphate were found in the benfotiamine group (both P < 0.001 vs. placebo). However, no significant differences in changes in peripheral nerve function or soluble inflammatory biomarkers were observed between the groups.

CONCLUSIONS

Our findings suggest that high-dose benfotiamine (300 mg/day) supplementation over 24 months has no significant effects upon peripheral nerve function or soluble markers of inflammation in patients with type 1 diabetes.Benfotiamine, a synthetic thiamine monophosphate analog with improved bioavailability compared with thiamine (1), has been shown to prevent the development of microvascular complications in rats without changes in glycemic control (2). Short-term studies (3–12 weeks) in humans have suggested that high-dose benfotiamine (up to 600 mg/day) can improve symptomatic scores in diabetic polyneuropathy (3–5). To assess the efficacy of long-term supplementation, we conducted a 24-month, randomized, double-blind, placebo-controlled study of the effects of 300 mg/day benfotiamine supplementation on peripheral nerve function and inflammatory markers in patients with type 1 diabetes.