Incidence of NIDDM and Impaired Glucose Tolerance in Hypertensive Subjects: The San Antonio Heart Study

Hypertension often occurs in association with NIDDM and IGT. We examined the association of hypertension at baseline to the 8-yr incidence of NIDDM and IGT in 1471 subjects who participated in the San Antonio Heart Study. Subjects who were hypertensive at baseline had a higher incidence of NIDDM (8.9 vs. 4.9%, P = 0.041) and IGT (25.2 vs. 10.0%, P < 0.001) than subjects who were normotensive at baseline. After adjusting for age, sex, ethnicity, obesity, body fat distribution, fasting glucose, and insulin, this excess was eliminated for NIDDM, but not for IGT. Specifically, the adjusted OR for NIDDM in hypertensive versus normotensive patients was 0.73 (95% Cl 0.34–1.58), whereas the adjusted OR for IGT was 1.87 (95% Cl 1.08–3.22). The excess risk of NIDDM in hypertensive patients can be explained by their greater age, obesity, more unfavorable body fat distribution, and hyperinsulinemia, whereas the excess risk of IGT is independent of these factors.