LISINOPRIL ADMINISTRATION IMPROVES INSULIN ACTION IN AGED PATIENTS WITH HYPERTENSION

Thirty elderly, mildly hypertensive patients were enrolled for a singl e-blind, randomised cross-over placebo controlled trial in which place bo and lisinopril (20 mg/day before breakfast) were given for 4 and 8 weeks, respectively. A wash-out period of 3 weeks between placebo and lisinopril was observed. In each patient a euglycaemic glucose clamp w ith simultaneous indirect calorimetry allowed us to determine whole bo dy glucose disposal and substrate oxidation. Changes in morning SBP an d DBP were also determined. Lisinopril vs. placebo significantly impro ved whole body glucose disposal (40.4+/-0.4 vs. 30.3+/-0.4 mu mol/kg L BM x min; P < 0.01), non-oxidative glucose metabolism (18.1+/-0.7 vs. 10.9+/-0.6 mu mol/kg LBM x min; P < 0.01) and fasting plasma potassium levels (4.8+/-3 vs. 4.4+/-0.4 mmol/l; P < 0.05). SBP (175+/-3..,3 vs. 160+/-3.0 mm Hg; P < 0.001) and DBP (106+/-2.3 vs. 95+/-2.0 mm Hg; P < 0.001) were significantly reduced by lisinopril administration. Afte r ACE inhibition, fasting plasma potassium levels correlated with the decline in mean arterial BP (r=-0.71; P < 0.006). In conclusion, lisin opril administration reduces arterial BP and improves insulin sensitiv ity in elderly hypertensive patients.