Reduced serum levels of L-carnitine in patients with non-insulin dependent diabetes mellitus

The present study was designed to determine if serum levels of L-carnitine, free fatty acids and triacylglycerols can serve as markers for type II diabetes. To do so, blood samples were collected from 50 NIDDM patients and 20 normal subjects. Serum insulin, glucose, L-carnitine and blood lipids such as triglycerides, cholesterol and free fatty acids were determined in these samples. Serum insulin levels in diabetic subjects were higher than normal subjects (diabetes 13.3±1.3U/l, controls 7.2±0.7U/l, p<0.01). Triglycerides and cholesterol levels in diabetic subjects were also higher than normal control despite the fact that values in diabetic subjects were within normal range. The free fatty acid levels were higher in diabetic subjects than normal controls (diabetes 0.81 ±0.035mmol/ 1, controls 0.52 ± 0.03mmol/l, p<0.001). Blood free fatty acid levels significantly correlated with the fasting and postprandial blood glucose levels in diabetic subjects (r = 0.65 & 0.49, p<0.001 of FFA vs fasting and postprandial blood glucose). In contrast, L-carnitine was decreased in diabetic subjects (diabetes 31.1 ± 0.217 μmol/l, controls 60.8± 0.19, p<0.001. Blood L-carnitine levels significantly correlated with the fasting, postprandial blood glucose levels, and insulin levels in diabetic subjects (r = -0.55 & -0.36, p<0.001 & 0.001 of L-carnitine vs fasting and postprandial blood glucose). These findings suggest that increased serum free fatty acids and decreased levels of L-carnitine could be used as markers for type II diabetes.