Publication:

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

Background 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.