Is prehypertension a risk factor for the development of type 2 diabetes?

OBJECTIVE - Prehypertension is associated with cardiovascular disease and insulin resistance. However, whether subjects with prehypertension have more diabetes risk is not known. We examine whether prehypertension is a risk factor for developing type 2 diabetes. RESEARCH DESIGN AND METHODS - Incident diabetes was examined in nondiabetic normotensive participants in the San Antonio Heart Study (n = 2,767; aged 25-65 years; median follow-up 7.8 years). RESULTS - Incident diabetes was 12.4% in subjects with prehypertension and 5.6% in subjects with normal blood pressure. The odds of incident diabetes were 2.21 greater for individuals with prehypertension than for those with normal blood pressure (95% CI 1.63-2.98) after adjusting for age, sex, and ethnicity. Prehypertension was not associated with incident diabetes after additional adjustment for BMI, impaired glucose tolerance, insulin resistance and secretion, and family history of diabetes (odds ratio 1.42 [95% CI 0.99-2.02]). CONCLUSIONS - Subjects with prehypertension are at increased risk of diabetes. Much of this risk is explained by disorders related to the insulin resistance syndrome.