Effect of amlodipine on insulin resistance & tumor necrosis factor-alpha levels in hypertensive obese type 2 diabetic patients

Abstract

Background & objectives: Tumour necrosis factor-alpha (TNF-α) has been suggested to play a key role in insulin resistance (IR) in obesity and may contribute to the development of type 2 diabetes mellitus. Recently, studies are focused on the effect of antihypertensive drugs on insulin sensitivity and cytokines. We undertook this study to evaluate the effect of amlodipine, a long-acting dihydropyridine calcium channel blocker treatment on TNF-α, homeostasis model assessment (HOMA) IR and leptin levels in obese hypertensive type 2 diabetic patients. Methods: Amlodipine 5-10 mg for 12 wk was given to type 2 diabetic patients in the amiodipine group. Pre- and post-treatment values of laboratory parameters in the amlodipine group were compared with those of normotensive nondiabetic obese controls. At baseline blood pressures (BP) and metabolic parameters were measured in all patients and repeated after 12 wk in the amlodipine group. Results: Basal waist-to-hip ratio, systolic and diastolic BPs, fasting glucose, TNF-α and HOMA-IR values of the amlodipine group were higher than the control group. No difference was detected in body mass index, fasting insulin, hemoglobin Alc and leptin values between groups. The systolic and diastolic BPs, fasting glucose, HOMA-IR and TNF-α values decreased significantly after the treatment. But, there was no correlation between percentage change in TNF-α and HOMA-IR. Interpretation & conclusion: Besides reducing BP, amlodipine seemed to improve IR and decrease TNF-α levels. In this context, these properties may provide additional benefits of antihypertensive drug regimens chosen for this population, but larger group interventions are needed.