Weight gain in insulin-treated patients by body mass index category at treatment initiation: new evidence from real-world data in patients with type 2 diabetes

AimsTo evaluate, in patients with type 2 diabetes (T2DM) treated with insulin, the extent of weight gain over 2years of insulin treatment, and the dynamics of weight gain in relation to glycaemic achievements over time according to adiposity levels at insulin initiation. Materials and methodsPatients with T2DM (n=155917), who commenced insulin therapy and continued it for at least 6months, were selected from a large database of electronic medical records in the USA. Longitudinal changes in body weight and glycated haemoglobin (HbA1c) according to body mass index (BMI) category were estimated. ResultsPatients had a mean age of 59years, a mean HbA1c level of 9.5%, and a mean BMI of 35kg/m(2) at insulin initiation. The HbA1c levels at insulin initiation were significantly lower (9.2-9.4%) in the obese patients than in patients with normal body weight (10.0%); however, the proportions of patients with HbA1c >7.5% or >8.0% were similar across the BMI categories. The adjusted weight gain fell progressively with increasing baseline BMI category over 6, 12 and 24months (p<.01). The adjusted changes in HbA1c were similar across BMI categories. A 1% decrease in HbA1c was associated with progressively less weight gain as pretreatment BMI rose, ranging from a 1.24kg gain in those with a BMI <25kg/m(2) to a 0.32kg loss in those with a BMI > 40kg/m(2). ConclusionsDuring 24months of insulin treatment, obese patients gained significantly less body weight than normal-weight and overweight patients, while achieving clinically similar glycaemic benefits. These data provide reassurance with regard to the use of insulin in obese patients.