Effects of selective imidazolin-1 receptor agonists’ vs dihydropyridine calcium channel blockers on insulin resistance in patients of hypertension with metabolic syndrome: a meta-analysis of randomized controlled trials

Abstract

Co-existence of insulin resistance in pre-diabetic hypertensive patients is associated with the higher risk for onset of diabetes and higher incidences of cardiovascular events in existing diabetics. Hence there is a need for selecting an anti-hypertensive drug with favourable metabolic effects. Present study aims at comparing the metabolic and hemodynamic effects of selective imidazolin-1 (I1) receptor agonists vs dihydropyridines (DHPs). Methods: After electronic data base search in PUBMED, Cochrane library and EMBASE, total four RCTs were found eligible and included in analysis. Two studies used moxonidine (0.2-0.4mg), other two used rilmenidine (1-2mg) as selective I1-agonists and among DHPs, amlodipine (5-10mg) was used in three studies and isradipine (5-10mg) in one. Results: Use of DHPs was associated with significant decrease in DBP (MD = - 2.37mm Hg; 95% CI:-1.39, -3.36) both at the end of short-term (3 months) and long-term (6 months) treatment. Significant decrease in fasting serum insulin level (MD = -2.63mU/L; 95% CI:-4.66, -0.60) and HOMA index for insulin resistance (MD = -1.14, 95% CI:-1.48, -0.80) observed in patients treated with I1-agonists at three months were not persistent at the end of six months. Effects of both groups of drugs on plasma lipids concentration were inconclusive. Conclusions: In addition to the concern over safety of I-1 agonists in heart failure patients, there is a lack of data on therapeutic benefits of I1-agonists on cardiovascular related events in hypertension. Hence for time being and with available evidences, DHPs seem to be better choice than I1-agonists in hypertensive patients with metabolic syndrome.