AIM: To evaluate the efficacy of the short-acting glucagon-like peptide-1 receptor agonist, exenatide, added to insulin therapy in type 1 diabetes on bone mineral density and bone turnover markers.

MATERIALS AND METHODS: In a randomized, double-blinded, parallel-group trial, 108 individuals with type 1 diabetes aged 18 years or older on basal-bolus therapy with HbA1c 59-88 mmol/mol (7.5%-10.0%) and body mass index of more than 22.0 kg/m2 were randomized (1:1) to preprandial subcutaneous injection of 10 μg exenatide (Byetta) before breakfast, lunch, and dinner over 26 weeks as add-on treatment to insulin therapy.

RESULTS: Exenatide elicited a body weight reduction of 4.4 kg compared with placebo, but no between-group differences in bone mineral density, as assessed by whole-body, hip, lumbar, and forearm dual-energy X-ray absorptiometry following 26 weeks of treatment, were observed. Fasting plasma levels of C-terminal telopeptides of type I collagen, a marker of bone resorption, and amino-terminal propeptide of type I procollagen, a marker of bone formation, were unchanged by exenatide compared with placebo after 26 weeks.

CONCLUSIONS: Despite an exenatide-induced body weight reduction, no changes in bone metabolism were observed with exenatide added to insulin therapy in type 1 diabetes after 26 weeks.