Relationship between myoinositol influx and lipids in diabetic neuropathy

Diabetic neuropathy is associated with abnormalities in lipid metabolism and has been postulated to be associated with abnormal myoinositol metabolism. Leucocyte myoinositol influx was measured using a triple isotope method in long-standing type 1 (insulin-dependent) diabetic patients with and without diabetic neuropathy and in a group of matched controls. No differences in fasting lipid, glucose concentrations or glycated haemoglobin were found in the diabetic groups. Myoinositol influx was significantly but negatively correlated with the serum very low density lipoprotein (VLDL) cholesterol concentration in patients with and without neuropathy but not in the controls. The VLDL cholesterol concentration also correlated negatively with the transporter Km (Rs = -0.87, P < 0.005, neuropathic group only) and Vmax (Rs = -0.93, P < 0.001, neuropathic group; Rs = -0.59, P < 0.05, non-neuropathic group). Myoinositol influx correlated with the glycated haemoglobin only in the diabetic patients without neuropathy. The lipid relationships in diabetic subjects were independent of glucose control, which suggests that myoinositol influx mechanisms represent another transporter affected by intracellular lipid metabolism. The control of VLDL metabolism by fibrates could offer a method for reducing the progression of diabetic neuropathy.