Vascular hypertrophy in borderline hypertension: relationship to blood pressure and sympathetic drive

Abstract

While borderline hypertension increases the chance for cardiovascular disease, most with borderline hypertension will not experience problems. Thus, the risk of intervening probably outweighs benefit for the majority. However, those with target organ damage are probably at higher risk and might benefit from more aggressive management. Therefore, we assessed vascular hypertrophy and average home blood pressures in patients with borderline hypertension which might be of value in therapeutic planning. Minimum forearm vascular resistance (mFAVR) was used as an index of vascular hypertrophy. Comparing ten normotensive controls to twenty individuals with borderline hypertension revealed a significant difference in mFAVR (1.7 +/- 0.06 vs 2.1 +/- 0.1, p less than .05). There were obvious differences in blood pressure between normotensives and borderlines which contributed to differences in mFAVR. However, within the group with borderline hypertension, no relationship was apparent between mean blood pressure and mFAVR, r = 0.13, NS. Among the borderline hypertensives, baseline plasma norepinephrine correlated with mFAVR, r = 0.48, p less than .05, suggesting that the sympathetic nervous system contributes to vascular hypertrophy in this group. In a separate group of individuals with nine normotensives and nine borderline hypertensives we wished to find if average home blood pressure would correlate better with mFAVR than a single laboratory measurement. While both the home (r = 0.56, p less than .05) and laboratory (r = 0.66, p less than .01) MBP correlated significantly with mFAVR, the data did not confirm the hypothesis that the average home blood pressures would better predict the degree of vascular hypertrophy. These data show that a substantial proportion of patients with borderline hypertension have evidence for vascular hypertrophy, sympathetic drive might contribute to vascular hypertrophy in borderline hypertension, average home blood pressures did not aid in separating those with and without evidence for vascular hypertrophy.