COMPARATIVE EFFECTS OF LISINOPRIL AND LOSARTAN ON INSULIN SENSITIVITYIN THE TREATMENT OF NON DIABETIC HYPERTENSIVE PATIENTS

Aims The aim of this study was to compare the effects of the ACE-inhib itor lisinopril and the angiotensin II receptor antagonist losartan on insulin sensitivity in the treatment of non diabetic hypertensives. M ethods Twenty-five non diabetic subjects with mild to moderate hyperte nsion, 11 females and 14 males, aged 44-63 years, after a 4-week wash- out period on placebo, were randomized to receive lisinopril 20 mg onc e daily or losartan 50 mg once daily for 6 weeks. Following another 4- week wash-out period, patients were crossed to the alternative regimen for further 5 weeks. At the end of the placebo and of the active trea tment periods, blood pressure (BP) was measured (by standard mercury s phygmomanometer, Korotkoff I and V) and insulin sensitivity was assess ed by the euglycaemic hyperinsulinaemic clamp technique. Glucose infus ion rate (GIR) during the last 30 min of clamp and total glucose requi rement (TGR) were evaluated. Results Both lisinopril and losartan sign ificantly reduced SBP (by a mean of 20.2 and 17.2 mmHg, respectively) and DBP (by a mean of 15.2 and 12.3 mmHg, respectively), with no diffe rence between the two treatments. GIR, used as an indicator of insulin sensitivity, was significantly increased by lisinopril (+1.5 mg min(- 1) kg(-1), P<0.05 vs baseline) but not by losartan (+0.42 mg min(-1) k ig(-1), NS), the difference between the two drugs being statistically significant (P<0.05). TGR was increased by lisinopril (+7.3 g, P<0.05 vs baseline), whereas losartan did not significantly modify it (+1.9 g , NS). Conclusions In conclusion, with all cautions due to an absence in this study of a randomized placebo phase, our findings suggest that lisinopril improved insulin sensitivity whereas losartan did not affe ct it.