Effect of moxonidine and amlodipine on serum YKL-40, plasma lipids and insulin sensitivity in insulin-resistant hypertensive patients-a randomized, crossover trial.

Moxonidine is a selective imidazoline receptor agonist with comparable blood pressure-lowering efficacy to first-line antihypertensives and favorable metabolic effects. YKL-40 (chitinase-3-1-protein) has been proposed as a new marker of inflammation, atherosclerosis and endothelial dysfunction in neoplastic, cardiovascular and metabolic diseases but has not yet been studied in the context of essential hypertension. Fifteen patients (10 M, 5 F; age 48+/-14 years) with arterial hypertension and insulin resistance (HOMA-IR index >2.77) on at least two antihypertensive drugs were randomized to receive either moxonidine (0.4 mg) or amlodipine (10 mg) for two 8-week periods with a 7-day wash-out. Serum insulin, glucose, C-reactive protein (CRP), lipids, uric acid, YKL-40 and blood pressure were measured and insulin sensitivity was calculated (HOMA) at the beginning and end of each study phase. Mean BP decreased significantly with both moxonidine and amlodipine (-9.8+/-7.6 and -10.4+/-7.3 mm Hg, respectively). Serum high-density lipoprotein cholesterol increased with both therapies, but only moxonidine-affected serum triglycerides. No significant changes in serum uric acid, CRP, YKL-40 (2.3 and 3.3 ng ml(-1), respectively) or HOMA index (0.70+/-2.4 and 0.76+/-2.8) were observed. There was a strong negative correlation between serum uric acid and YKL-40 concentration at baseline (r=-0.77, P=0.01). Serum YKL-40 did not correlate with blood pressure, biochemical parameters or HOMA index. Moxonidine is an effective adjunctive antihypertensive agent for use in patients with hypertension and insulin resistance that induces beneficial effects on serum lipid profile but does not reduce insulin resistance, inflammation or serum YKL-40 concentration.