Weight change after initiation of oral hypoglycemic monotherapy for diabetes predicts 5-year mortality: An observational study.

PURPOSE: To investigate whether weight change in the first year after initiating an oral hypoglycemic agent (OHA) for type 2 diabetes treatment is associated with mortality in a national cohort.

PROCEDURES: We prospectively followed Veterans Health Administration patients with type 2 diabetes initiating treatment with an OHA and not receiving any other diabetes pharmacotherapy for at least one year. Information on OHAs, weight, co-morbidities, other medications, demographics, and laboratory measurements was obtained from electronic medical records. Logistic regression was used to estimate 5-year mortality odds by weight change during the first year after OHA treatment initiation.

FINDINGS: Patients (mean age 65years, 97% male, mean BMI 32.3kg/m) initiating OHA monotherapy between 2003 and 2008 totaled 145,198 (metformin n=89,111, glipizide n=27,100, glyburide n=25,226, rosiglitazone n=3,761). Most patients (65%) maintained a stable weight (change ⩽5% from baseline) during the first year after OHA initiation. Those losing >5% of baseline weight had a significantly higher odds of death over the subsequent 5-years ranging from 1.64 to 2.13 depending on OHA type. In the metformin group, weight gain >5% of baseline was also associated with higher odds of 5-year mortality. The same results were obtained after conducting three sensitivity analyses that excluded patients for the following reasons: weight loss in the one year prior to OHA initiation, weight change >100lbs, or weight change >50lbs.

CONCLUSIONS: Weight loss was associated with higher odds of 5-year mortality among patients initiating an OHA, as was weight gain for metformin only.