Association between the blood pressure response to a change in posture and the 6-year incidence of hypertension: prospective findings from the ARIC study.

The association between the blood pressure response to a change from the supine to the standing position and the 6-year incidence of hypertension was studied in a bi-ethnic, middle-aged cohort of 6951 normotensive men and women free of coronary heart disease at baseline. Postural change in systolic blood pressure (SBP) was categorized into deciles, and the middle four deciles served as the referent (no change) group. In unadjusted analyses, the incidence of hypertension was higher among both those with SBP increases and decreases relative to those in the referent group. Associations were modestly attenuated after controlling for age, ethnicity, and gender and cardiovascular disease risk factors. However, after adjustment for baseline, seated SBP, a modest association with incident hypertension persisted only for SBP decreases. Orthostatic hypotension (upon standing) was associated with incident hypertension and isolated systolic hypertension and, unexpectedly, this increased risk was highest among those with the lowest levels of baseline, resting SBP.