Determinants of new-onset diabetes among 19,257 hypertensive patients randomized in the Anglo-Scandinavian Cardiac Outcomes Trial--Blood Pressure Lowering Arm and the relative influence of antihypertensive medication.

Abstract

The purpose of this study was to determine the baseline predictors of new-onset diabetes (NOD) in hypertensive patients and to develop a risk score to identify those at high risk of NOD. Among 19,257 hypertensive patients in the Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm (ASCOT-BPLA) who were randomly assigned to receive one of two antihypertensive regimens (atenolol +/- thiazide or amlodipine +/- perindopril), 14,120 were at risk of developing diabetes at baseline. Of these, 1,366 (9.7%) subsequently developed NOD during median follow-up of 5.5 years. A multivariate Cox model was developed to identify the independent predictors of NOD and individual risk scores. NOD was significantly associated with an increase in baseline fasting plasma glucose (FPG), BMI, serum triglycerides, and systolic blood pressure. In contrast, amlodipine +/- perindopril in comparison with atenolol +/- thiazide treatment (hazard ratio 0.66 [95% CI 0.59-0.74]), high HDL cholesterol, alcohol use, and age >55 years were found to be significantly protective factors. FPG was the most powerful predictor with risk increasing by 5.8 times (95% CI 5.23-6.43) for each millimole per liter rise >5 mmol/l. The risk of NOD increased steadily with increasing quartile of risk score, with a 19-fold increase (95% CI 14.3-25.4) among those in the highest compared with those in the lowest quartile. The model showed excellent internal validity and discriminative ability. Baseline FPG >5 mmol/l, BMI, and use of an atenolol +/- diuretic regimen were among the major determinants of NOD in hypertensive patients. The model developed from these data allows accurate prediction of NOD among hypertensive subjects.