A prospective study of glycemia, body size, insulin resistance and the risk of hypertension in Mauritius

Objective To estimate the associations between new-onset hypertension and glycemia, insulin resistance, and overall and regional adiposity in a prospective study conducted in Mauritius. Research design and methods Three thousand five hundred and eighty-one adults without hypertension, pregnancy, or known diabetes at baseline (1987) were followed for incident hypertension in 1992 and 1998, (systolic blood pressure >= 140mmHg or diastolic blood pressure >= 90mmHg or antihypertensive medication treatment). Other measurements included fasting plasma glucose and 2-h plasma glucose after a 75-g oral glucose load, fasting insulin, BMI, waist circumference, smoking, alcohol use, exercise, and demographic information. Insulin sensitivity was estimated by the computerized homeostasis model assessment (HOMA2) program. Results In multivariable logistic models that included age, gender, ethnicity, alcohol use, exercise, education, systolic blood pressure, diastolic blood pressure, homeostasis model assessment, fasting plasma glucose, 2-h plasma glucose, BMI, and waist circumference, the independent predictors of incident hypertension by time of follow-up were (odds ratio for a 1 SD increase; 95% confidence interval): 1992 - age (1.73; 1.47-2.03), Creole ethnicity (1.42; 1.04-1.94), 2-h plasma glucose (1.26; 1.04-1.51); 1998 - age (1.60; 1.40-1.83) andBMI (1.33; 1.05-1.69). Also, systolic blood pressure and diastolic blood pressure significantly predicted hypertension at both time points. Conclusion Risk factor patterns depended on duration of follow-up. Over 5 years, hypertension was related to 2-h plasma glucose but not to measures of body size or homeostasis model assessment, while over 11 years, incident hypertension was related to BMI but not waist circumference, 2-h plasma glucose, or homeostasis model assessment. These findings support a more important role for 2-h plasma glucose and overall adiposity than waist circumference, fasting plasma glucose, or insulin resistance in the development of hypertension in Mauritius.