Long-term plasma catecholamines in patients with hypertension and left ventricular hypertrophy treated with losartan or atenolol: ICARUS, a LIFE substudy.

Hypertension is a major risk factor for morbidity and mortality. Plasma catecholamines are linked to the pathogenesis of hypertension. Pharmacological intervention, including treatment with beta-blockers, reduces cardiovascular mortality and morbidity. In the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study, the angiotensin receptor blocker losartan significantly reduced cardiovascular end points compared to the beta-blocker atenolol. Thus, for the first time, one drug was shown to be superior to another in hypertension. The present substudy examined the effects of atenolol vs losartan treatment on plasma catecholamines at rest and during hyperinsulinaemia in a cohort of 86 LIFE patients. Plasma adrenaline increased significantly from placebo treatment at baseline to year 1 of treatment (P<0.0001), and also during hyperinsulinaemia (P<0.0001). Plasma noradrenaline did not change significantly from placebo treatment at baseline to year 1, but increased significantly during hyperinsulinaemia both at baseline and at year 1 (P<0.0001 for both). There were no differences in plasma catecholamines or the relative changes between the two treatment arms at any stage. In a subset of 42 patients examined also at years 2 and 3, these findings were confirmed during long-term treatment. Thus, losartan had an effect on plasma catecholamines comparable to that with the beta-blocker atenolol in patients with hypertension and left ventricular hypertrophy at rest and during hyperinsulinaemia. We find it unlikely that a difference in sympathetic activity explains the outcome benefits of losartan over atenolol in the LIFE study.