Weight, urinary electrolytes and blood pressure--results of several community based studies.

One hundred and seventy-nine Negro females, originally seen in high school in 1965, were visited at home during the summers of 1968 or 1969, and were revisited at home during 1978 or 1979. Weight, blood pressure, and urinary electrolyte excretion rates were obtained during the 1968-1969 studies. This report relates the previous measurements to the current (follow-up) blood pressure levels. 52 of the 179 have been told by a physician that they have high blood pressure, and 16 are now taking antihypertensive medication. The group now on medication were 27 lbs heavier and had higher blood pressures, 123/76 vs 114/70 in 1968-1969 than the remainder of the cohort, and their 24-hr urinary sodium excretion rate was greater, 5.9 vs 4.4 mEq/hr (p = 0.06). Among the groups now on therapy, the overnight K rate and Na/Ca ratio were inversely related to the 1968-1969 diastolic BP and the 24-hr Na rate and Na/K ratio were positively correlated with the 1968-1969 blood pressure, both systolic and diastolic. These associations were diminished when partial correlation coefficients adjusted for weight were calculated. Similar associations were not observed among the remainder of the cohort, suggesting that among persons who have the propensity to become hypertensive, the influence of factors which may produce hypertension such as sodium and/or obesity is more easily discernible.