Insulin Therapy Does Not Itself Induce Weight Gain in Patients With Type 2 Diabetes

Of obese individuals who lose weight by dieting, >90% eventually return to their original weight; one- to two-thirds of the lost weight is regained within 1 year, and almost all is regained within 5 years. This suggests that body weight is physiologically controlled and that weight changes, in either direction, elicit a potent counter response that resists the change (1). This should also hold true when weight loss is attributable to high blood glucose levels and/or insulin deficiency. Insulin is often first prescribed to type 2 diabetic patients after a period of poor metabolic control by oral agents; this period may be accompanied by weight loss due to insulin deficiency and/or the poor metabolic control itself. We postulated that the weight gain observed during insulin therapy in patients with type 2 diabetes may simply correspond to re-expression of their physiologically controlled body weight. We tested the hypothesis that insulin-treated type 2 diabetic patients might return to the previous maximal weight they reached before the onset of diabetes- and insulin deficiency–induced weight loss. We conducted a retrospective cohort study of 58 patients with type 2 diabetes who required insulin because of poor metabolic control, despite dietary measures and maximal-dose oral agents (e.g., glibenclamide 15 mg/day and metformin 1,700 mg/day). Insulin-treated type 2 diabetic patients were included in the study if they met the following criteria: 1 ) diagnosis of …