The 24-hour effects of glyburide and chlorpropamide after chronic treatment of type II diabetic patients.

A single-blind, randomized, comparative evaluation of glyburide (GL) and chlorpropamide (CP) therapy was performed in twenty previously untreated patients with non-insulin dependent diabetes mellitus (NIDDM) of about two years duration. Only newly diagnosed patients who were never treated and whose fasting blood glucose (FBS) levels were greater than 140 mg/dl after a six to eight week trial of dietary restriction were evaluated. Metabolic studies were performed before and after four months of therapy. GL and CP produced essentially the same effects on serum levels of glucose, insulin, glucagon (IRG), growth hormone (GH), cholesterol, and triglyceride. The mean 24-hour glucose levels for both the GL and CP groups were significantly lower than the pretherapy values (p less than 0.001). The mean 24-hour insulin levels did not change significantly during therapy (p greater than 0.05). Excellent control of plasma glucose was possible during the entire day without producing nocturnal hypoglycemia. Neither GL nor CP therapy influenced the mean 24-hour levels of IRG, GH, or cholesterol. However, mean 24-hour levels of triglyceride were lower in both groups. IRG levels were elevated and the pattern of change in the insulin and IRG levels paralleled each other, which suggested that glucagon may play a role in the resistance of insulin action in NIDDM. GH levels were normal and remained unchanged during therapy. It was concluded that detailed 24-hour studies are important for better understanding the spectrum of abnormalities in newly diagnosed patients with NIDDM who were never treated.(ABSTRACT TRUNCATED AT 250 WORDS)