Blood pressure profile, urinary sodium and body weight in the 'Oraon' rural and urban tribal community.

Blood pressure and nutritional profiles in the 'Oraon' tribal community of India living in rural and urban areas were studied between 1981-85 after a house to house survey of 4523 rural tribal people (RT) and 935 of their urban tribal counterparts (UT). Prevalence of hypertension was found to be 4.8/1000 males and 4.3/1000 females in rural tribal group giving an overall rate of 4.6/1000. In contrast the same were 27.1/1000 males and 21.4/1000 females in UT group, overall rate being 25.6/1000. Average calorie consumption were 1750 and 2280 and mean 24 hour-urinary sodium excretions 58 and 118 milliequivalents in RT and UT groups respectively. Of the total of 21 subjects in RT and 24 in UT detected to be hypertensive, 7 had common family inheritance. Increased mean arterial pressure correlated with increased sodium consumption and body weight. Hypertensives from both the groups showed higher urinary sodium excretion (P < 0.05). This epidemiologic study proves the role of a genetic factor/defect complicated by higher salt consumption in causation of increased blood pressure.