Long-term effects on insulin sensitivity and sodium transport in glucose-intolerant hypertensive subjects when beta-blockade is replaced by captopril treatment.
Long-term effects on insulin sensitivity and leucocyte sodium transport were studied in 42 glucose-intolerant hypertensives on beta-blockers, randomly assigned to continuous beta-blockade (beta group) or a switch to captopril treatment (mean daily dose 69.1 mg) (ACE group). In the ACE group, despite a tendency towards improvement, glucose uptake during the euglycaemic insulin clamp procedure did not change significantly from the baseline value of 4.0(0.5-12.9) mg/kg/min, values at 6 and 12 months being 4.8(1.3-14.7) and 4.4(1.5-9.8) mg/kg/min, respectively: the corresponding values for the beta group were 4.2(1.1-15.3), 3.6(1.2-8.9) and 4.0(1.5-12.0) mg/kg/min. The 22Na efflux rate constant, both baseline and follow-up values, was similar in both groups, and unrelated to insulin sensitivity. Owing to the surprisingly great variation in peripheral glucose uptake, the subgroup with values below the median for the population as a whole (4.9 mg/kg/min) was evaluated separately: those switched to captopril treatment manifested a 60% improvement in glucose disposal at 6 months and persisting at 12 months, the respective values being 2.1(0.5-4.8) (baseline), 3.5(1.3-6.3) and 3.4(1.5-6.1) mg/kg/min, (P = 0.012). The body mass index (BMI) was not significantly affected. Values for BMI, peripheral insulin and triglycerides were higher in the subgroup with glucose disposal below the median than in the subgroup with values above the median. Correlation between BMI and glucose uptake was highly significant (r = -0.75, P = 0.0001). The present findings suggest that captopril may be a better alternative than beta-blockers for treating the highly insulin-resistant, glucose-intolerant patients, predominantly to be found among the overweight.
Department of Medicine, University of Lund, Malmö General Hospital, Sweden.
K
K
Berntorp
F
F
Lindgärde
I
I
Mattiasson
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D015992:Body Mass Index; D002216:Captopril / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D005951:Glucose Tolerance Test; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology*; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012964:Sodium / Q000493:pharmacokinetics*; D000254:Sodium-Potassium-Exchanging ATPase / Q000502:physiology; D013223:Statistics as Topic; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D000319:Adrenergic beta-Antagonists; D007328:Insulin; D014280:Triglycerides; D002216:Captopril; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D005947:Glucose