Objective: The Captopril Prevention Project (CAPPP) was designed as a prospective intervention trial comparing the effect of a treatment based on the angiotensin-converting enzyme (ACE) inhibitor captopril with that of a conventional diuretic and/or beta-blocker-based therapy, in 10,985 hypertensive patients. There was no difference in the primary cardiovascular morbidity and mortality endpoint. A lower incidence of diabetes mellitus during captopril treatment was observed in the whole CAPPP cohort that was non-diabetic at baseline (n = 10,413) as well as in such CAPPP patients that were previously untreated (n = 5033).
Methods and results: A multivariate analysis of variables associated with the risk of developing diabetes in CAPPP demonstrated that glucose, body mass index (BMI), haemoglobin (Hb), age, 'SBP x Untreated' (the interaction between systolic blood pressure at baseline and newly diagnosed hypertension), cholesterol and prior antihypertensive treatment came out as risk factors. Based on these factors, a risk score for development of diabetes was calculated for all non-diabetic patients, who were divided into tertiles. For each tertile of risk, captopril therapy was associated with a reduced risk of diabetes development compared with conventional diuretic and/or beta-blocker therapy. When the non-diabetic cohort was divided into two subcohorts; previously treated and previously untreated patients, it turned out that the risk factors for developing diabetes differed between these two subcohorts. Only glucose, BMI and Hb came out as risk factors in all analysed cohorts.
Conclusion: A captopril-based antihypertensive treatment regimen is associated with a lower risk of diabetes development, compared with conventional therapy based on diuretics and/or beta-blockers.