COMPARISON OF THE POSSIBLE CARDIAC EFFECT OF SITAGLIPTIN, METFORMIN AND GLIMEPIRIDE ON INSULIN INDUCED HYPOGLYCEMIA IN RABBITS

Background Hypoglycemia is a common in diabetic patients, especially during strict blood glucose control with insulin and oral hypoglycemic drugs. Acute or recurrent hypoglycemia may cause sudden death during diabetes mellitus treatment, the cause of which is not well known and was attributed to cardiovascular complications. Objectives To measure the effect of insulin on troponin T, C-Reactive Protein (CRP), and malondialdehyde (MDA) and the ECG changes, and to compare the possible additive effect of sitagliptin, metformin and glimepiride on these parameters Methods Fifty rabbits ( twenty five males) were randomly divided into five groups ( 10 each ); 5 male and 5 female Group 1: (control group), Group 2:( insulin), Group 3: (Metformin + Insulin), Group 4: (Glimepiride + insulin), Groups 5: (Sitagliptin + Insulin). Animals were anesthetized with ketamine for ECG recording at day 3and were then sacrificed. Blood was collected for measurement of troponin T in both the serum and heart tissue, serum CRP, serum potassium and heart tissue Malondialdehyde. Results Insulin significantly increased serum CRP (0.15 ± 0.09 mg/l) and decreased in blood glucose level. Metformin + insulin increased in serum CRP (0.15 ± 0.103 mg/l), decreased in serum troponin T (124.62 ± 23.12 pg/ml), heart tissue MDA (0.52± 0.61 ng/ml), and decreased blood glucose level. Glimepiride + Insulin decreased in cardiac troponin T (200.60 ± 20.31 pg/ml) and blood glucose level. Sitagliptin + Insulin decrease in blood glucose level, p < 0.05, insignificant reduction in in serum and cardiac troponin T and heart tissue MDA. Insignificant increase in serum CRP and heart rate. Conclusions Metformin has both antioxidant activity and cardio-protective effect. While glimepiride has also cardio-protective effect. Insulin in combination or with oral hypoglycemic drugs cause a statistically significant decrease of blood glucose level with no therapeutic difference between various drugs.