The association between diabetes medication and weight change in a non-surgical weight management intervention: an intervention cohort study

Aim To compare weight change in a lifestyle-based weight management programme between participants taking weight-gaining, weight-neutral/loss and mixed diabetes medications. Methods Electronic health records for individuals (>= 18 years) with Type 2 diabetes who had been referred to a non-surgical weight management programme between February 2008 and May 2014 were studied. Diabetes medications were classified into three categories based on their effect on body weight. In this intervention cohort study, weight change was calculated for participants attending two or more sessions. Results All 998 individuals who took oral diabetes medications and attended two or more sessions of weight management were included. Some 59.5% of participants were women, and participants had a mean BMI of 41.1 kg/m(2) (women) and 40.2 kg/m(2) (men). Of the diabetes medication combinations prescribed, 46.0% were weight-neutral/loss, 41.3% mixed and 12.7% weight-gaining. The mean weight change for participants on weight-gaining and weight-neutral/loss diabetes medications respectively was -2.5 kg [95% confidence interval (CI) -3.2 to -1.8) and -3.3 kg (95% CI -3.8 to -2.9) (P = 0.05) for those attending two or more sessions (n = 998). Compared with those prescribed weight-neutral medications, participants prescribed weight-gaining medication lost 0.86 kg less (95% CI 0.02 to 1.7; P = 0.045) in a model adjusted for age, sex, BMI and socio-economic status. Conclusions Participants on weight-neutral/loss diabetes medications had a greater absolute weight loss within a weight management intervention compared with those on weight-gaining medications. Diabetes medications should be reviewed ahead of planned weight-loss interventions to help ensure maximal effectiveness of the intervention.