Background

Insulin-induced weight gain is a key concern for people with type 2 diabetes (T2D) and their treatment team. This study aimed to document the prevalence of insulin-induced weight gain and its impact on cardiovascular risk factors in patients attending the Royal Melbourne Hospital diabetes clinic.

Method

Clinical and biochemical data were extracted from the clinic database and from the hospital record. These variables were correlated to percentage weight change one year after starting insulin and compared between groups with or without clinically significant weight gain, defined as more than 7% of the baseline body weight.

Results

The population comprised 340 patients (184 male) whose mean±SD age and duration of diabetes was 63±11 and 13±8 years respectively. The mean (95% CI) change in body weight at one year was 3.0 (2.5 to 3.5) kg, but this was not associated with deleterious changes in blood pressure or lipid profile. Weight gain was associated with higher insulin doses, the use of short-acting insulin and with lower baseline body weight. Clinically significant weight gain occurred in 87 patients and was associated with glucose-lowering regimens that included short-acting insulin or a thiazolidinedione, whereas regimens that incorporated other oral agents, particularly sulfonylureas, were associated with less weight gain.

Conclusions

In this Australian tertiary hospital population with T2D, insulin-induced weight gain was common but was not associated with deleterious changes in blood pressure or lipids. Treatment regimens that avoid short-acting insulin but include oral agents other than thiazolidinediones might prevent insulin-induced weight gain in T2D.