Effects of insulin and sitagliptin on early cardiac dysfunction in diabetic rats.

AIMS: Cardiac affection is common in diabetic patients. Although insulin exerts a cardioprotective role, it may not be enough to totally prevent this affection. The current study aimed to compare the cardioprotective effect of insulin alone or combined with sitagliptin in a rat model of type 1 diabetes mellitus. MATERIALS AND METHODS: Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ; 60 mg/kg). Diabetic rats were treated with insulin (3 IU), insulin (6 IU), or insulin (3 IU) + sitagliptin (10 mg/kg) for 42 days. KEY FINDINGS: Diabetic rats exhibited significant systolic and diastolic cardiac affection with significant elevation of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and brain natriuretic peptide (BNP) levels. Treatment with insulin prevented the deterioration of diabetes-induced cardiac condition, an effect that was significantly potentiated by the combined use of sitagliptin. SIGNIFICANCE: The combined use of sitagliptin and insulin significantly improved the cardioprotective effect of insulin and prevented the early cardiac dysfunction in STZ diabetic rats.