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

Objectives: 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 ≥140 mmHg or diastolic blood pressure ≥90 mmHg 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) and BMI (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.