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

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.

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.

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.

The combined use of sitagliptin and insulin significantly improved the cardioprotective effect of insulin and prevented the early cardiac dysfunction in STZ diabetic rats.