Purpose: Patients with type 2 diabetes are commonly overweight, which can contribute to poor cardiovascular outcomes. beta-blockers may promote weight gain, or hamper weight loss, and are a concern in high-risk patients. The current analysis of the Glycemic Effect in Diabetes Mellitus: Carvedilol-Metoprolol Comparison in Hypertensives (GEMINI) trial evaluates the effects of carvedilol and metoprolol tartrate on weight gain in patients with type 2 diabetes and hypertension.
Methods: This prespecified secondary analysis of the GEMINI study (n=1106) evaluated change in body weight after 5 months.
Results: Mean (+/-SE) baseline weights were 97.5 (+/-20.1) kg for carvedilol and 96.6 (+/-20.1) kg for metoprolol tartrate. Treatment difference (c vs m) in mean (+/-SE) weight change from baseline was -1.02 (+/-0.21) kg (95% confidence interval [CI], -1.43 to -0.60; P <.001). Patients taking metoprolol had a significant mean (+/-SE) weight gain of 1.19 (+/-0.16) kg (P <.001); patients taking carvedilol did not (0.17 [+/-0.19] kg; P =.36). Metoprolol tartrate-treated patients with body mass index (BMI) >30 kg/m2 had a statistically significant greater weight gain than comparable carvedilol-treated patients. Treatment differences (c vs m) in the obese (BMI >30 kg/m2) and morbidly obese groups (BMI >40 kg/m2) were -0.90 kg (95% CI, -1.5 to -0.3; P =.002) and -1.84 kg (95% CI, -2.9 to -0.8; P =.001), respectively. Pairwise correlation analyses revealed no significant associations between weight change and change in HbA1c, HOMA-IR, or blood pressure.
Conclusions: Metoprolol tartrate was associated with increased weight gain compared to carvedilol; weight gain was most pronounced in subjects with hypertension and diabetes who were not taking insulin therapy.