Hypertension in blacks: socioeconomic stress and sympathetic nervous system activity.

Primary hypertension is almost twice as prevalent among American blacks as among whites. Causes of this increased prevalence of hypertension remain elusive. Elevation of sympathetic nervous system activity, in part secondary to increased levels of socioeconomic stress, is hypothesized as playing a role. Increased sympathetic nervous system activity may increase peripheral vascular resistance directly or through increased vascular reactivity. Microneurography allows direct measurement of peripheral sympathetic nervous system activity. Application of this technique will allow comparison of sympathetic nervous system activity in black and white subjects and provide additional insight into the role of the sympathetic nervous system in the development of hypertension in blacks.