Diabetes-related distress, insulin dose, and age contribute to insulin-associated weight gain in patients with type 2 diabetes: results of a prospective study.

OBJECTIVE The determinants of insulin-associated weight gain in type 2 diabetes mellitus (T2DM) are partly unknown. Therefore, we conducted a prospective study to identify predictors of insulin-associated weight gain. RESEARCH DESIGN AND METHODS In patients with T2DM, we assessed physical activity by accelerometry and measured diabetes-related distress by questionnaires before and 6 and 12 months after starting insulin therapy. Glycemic control (HbA1c) and insulin dose were monitored. RESULTS After 12 months of insulin therapy, mean body weight had increased by 3.0 ± 2.5 kg (P < 0.001). The drop in HbA1c was correlated with insulin-associated weight gain. With the use of a multiple linear regression model, a cluster of variables was identified that significantly related to weight gain. Diabetes-related distress, initial insulin dose, and the increase of insulin dose during the course of the study as well as age appeared to be important predictors of weight gain after initiation of insulin therapy. Physical activity (measured as MET) decreased from 1.40 ± 0.04 at baseline to 1.32 ± 0.04 MET (P < 0.05) but was not significantly related to weight changes. CONCLUSIONS Diabetes-related distress, initial and titration of insulin dose, and age all significantly predict insulin-associated weight gain. After the initiation of insulin therapy, physical activity decreased significantly, but this did not determine weight gain over the first 12 months. Our study findings may have clinical implications.