Immunoreactive insulin response to a single dose of glimepiride in lean type 2 diabetic subjects.

BACKGROUND: The best method for glucose lowering in lean type 2 diabetes remains controversial and this study was undertaken to study the 24 hour insulin response of these diabetics to glimepiride, a sulfonylurea with distinctive properties. METHODS: Twenty five consecutive newly diagnosed diet-unresponsive lean type 2 diabetics (BMI < 19 kg/m2) without any vascular complications were given single dose (1 mg) of glimepiride and insulin responses were measured 2,4,8,12 and 24 hours later. Pre and post-glimepiride blood glucose levels were also measured. RESULTS: All the post-glimepiride insulin levels were significantly higher than basal values. Increase in insulin secretion peaked at four hours and benefits lasted for at least 24 hours. This was accompanied by clinically and statistically significant reductions in fasting and postprandial blood glucose levels. Maximum secretory response correlated positively with beta cell function (HOMA) and negatively with fasting glucose. CONCLUSIONS: Glimepiride improved insulin secretion and hyperglycemia in lean type 2 diabetic subjects, with benefits lasting for 24 hours. The degree of response was proportional to the beta cell reserve, and occurred irrespective of the presence or absence of markers of insulin resistance.