Objective: To examine the long-term (15 months) effects on glycemic control and insulin secretion of glipizide and glyburide treatment in patients with non-insulin-dependent diabetes mellitus (NIDDM).
Research design and methods: Prospective, randomized, double-blind, placebo-controlled study on 46 NIDDM patients comparing fasting levels and test-meal responses of glucose and insulin during 15 months of follow-up.
Results: A comparable reduction in HbA1c levels by both agents versus placebo was observed throughout the study period, but after a marked initial reduction in both sulfonylurea groups, all three groups showed gradually increasing HbA1c levels. However, both glipizide and glyburide achieved and maintained lowered postprandial glucose levels and increased fasting and postprandial insulin levels compared with placebo.
Conclusions: Both glipizide and glyburide may achieve and maintain glycemic reduction and stimulation of insulin secretion during long-term treatment. However, these agents do not prevent the gradual increase in overall glycemia that develops over time in NIDDM patients.