The combination of insulin and metformin in treatment of non-insulin-dependent diabetes mellitus.

Objective: To assess whether, in the treatment of non-insulin-dependent diabetes mellitus (NIDDM), (1) metformin in conjunction with insulin can safely cause a decrease in glycosylated hemoglobin (HbA1c) to 7% or less and (2) this combination therapy may result in weight loss and lower insulin dose in comparison with insulin treatment alone. Methods: Forty patients with NIDDM being treated with insulin on their first visit to the Diabetes Center were identified by retrospective review of medical records of all patients encountered during a 1-year period. These patients were classified into groups who were receiving insulin only (group 1) or insulin + metformin (group 2) at the most recent visit. Group 2 was subdivided into those with a body mass index of either =30 kg/m2 (group 2A) or >30 kg/m2 (group 2B). Blood glucose, HbA1c, insulin dose, and weights were analyzed from their initial and most recent visits. Results: HbA1c decreased from 10 - 2.7% to 7 - 1.1% (P<0.01) in group 1 and from 9.8 - 2...