Metabolic precursors of hypertension. The San Antonio Heart Study

The relation of possible metabolic precursors (especially insulin resistance) to hypertension has been controversial. In addition, these associations may differ by level of obesity or ethnicity.

We followed up 1039 initially nondiabetic, nonhypertensive subjects from the San Antonio Heart Study for 7 years.

Hypertension developed in 93 subjects. Age, body mass index, waist-to-hip ratio, and fasting insulin and triglyceride levels predicted the development of hypertension in univariate analyses. After adjustment for age, body mass index, waist-to-hip ratio, gender, ethnicity, and fasting glucose levels, higher levels of triglyceride and fasting insulin predicted the development of hypertension. Body mass index and fasting insulin and triglyceride levels predicted the development of hypertension in Mexican Americans and non-Hispanic whites. In addition, fasting insulin levels predicted the development of hypertension in lean and obese subjects. Increased insulin secretion (as judged by the 30-minute insulin increment) on an oral glucose tolerance test also predicted the development of hypertension.

A cluster of atherogenic changes may precede the development of hypertension, and increased fasting insulin concentration predicts hypertension in important subgroups of subjects.