Longitudinal assessment of blood pressures in black and white children.

Abstract

The prevalence of hypertension is greater for blacks than whites. Whether black children have higher blood pressure than white children is less clear. We investigated this issue through a prospective longitudinal assessment of blood pressure in 345 white children and 164 black children. Each child had his or her blood pressure measured every 6 months for 2 to 5.5 years. The means for systolic and diastolic blood pressures for each individual were calculated, and the rate of change in blood pressure over time for each subject was estimated. The mean blood pressure and the mean rate were compared between gender-specific black and white groups. For both boys and girls, the mean systolic blood pressure was 2 mm Hg higher in black children than white children (/*=.0008). Boys had a higher systolic blood pressure than girls (P=.OO48). The mean diastolic blood pressure was 1.5 mm Hg higher in black children than in white children (P=.O27O); no significant gender difference in diastolic blood pressure was observed. Age, weight, height, and body mass index were highly correlated with blood pressure. When accounting for these variables, for girls the racial difference in systolic blood pressure remained significant, whereas the difference in diastolic blood pressure in boys and girls was no longer significant. The rate of increase in blood pressure over time was significantly greater in blacks than whites: for systolic blood pressure, P=.0002, and for diastolic blood pressure, P=.OO9. There was no sex difference in rate of change in systolic blood pressure, whereas girls showed a greater increase in diastolic blood pressure over time than boys (P=.O131). In summary, the average blood pressure for black children was higher than in white children, and the blood pressure increased at a faster rate in blacks compared with whites. The findings suggest that mechanisms that predispose blacks to hypertension may be functioning in childhood. (Hypertension 1993;22:84-89) KEY WORDS • blacks • blood pressure • hypertension, essential • child H ypertension is more common in blacks than in whites. 1 -2 It remains uncertain, however, whether blood pressure is higher in blacks than in whites before hypertension begins. Some crosssectional studies found slightly higher blood pressure in black children, 35 whereas others described inconclusive findings or found blood pressure to be lower in whites than in blacks.6 ' 9 In one study of adolescents, blood pressure at night was higher in blacks than in whites. 10 An increased level of arterial pressure in black children compared with white children would suggest that factors involved in the development of hypertension in blacks are functioning early in life. If the pathophysiology of the hypertension is indeed present in childhood, then studies that include young, normotensive individuals might provide useful information to an understanding of the etiology of hypertension.We describe here a prospective, longitudinal study of blood pressure in black and white children. Blood pressure was me...

Seven-Year Incidence of Hypertension in a Cohort of Middle-Aged African Americans and Whites

“…Earlier puberty and weight gain in African American children may partly explain the difference in BP. 26 Given the higher overall risk of hypertension in African Americans compared with whites, the results from our study are consistent with other studies 1,3,25,26 suggesting that the excess burden of hypertension in African Americans may be due primarily to a higher BP level and rise in BP with age in adolescence and young adulthood. Efforts to prevent high BP and its sequelae in African Americans need to target groups before they reach middle age.…”

“…24 -26 Manatunga and colleagues followed 164 African American and 345 white children for 2 to 5.5 years. 26 They found that the African American children had a significantly higher mean BP and rate of increase in BP over time. Earlier puberty and weight gain in African American children may partly explain the difference in BP.…”

Do variations in blood pressures of South Asian, African and Chinese descent children reflect those of the adult populations in the UK? A review of cross-sectional data

“…[16][17][18][19][20] In some of these USA studies, ethnic differences in BP were still present after adjusting for age, weight, height, and BMI. 16,17 The UK result is still more unexpected in the face of a comparatively high BMI in African descent children. This finding of similar BP in children of African descent is consistent with the findings of similar BP levels in the younger African groups in the UK's adult studies.…”

Racial Difference in the Activity of the Amiloride-Sensitive Epithelial Sodium Channel

“…19 For the amiloride study, members of the cohort were sent letters inviting them to participate. For the studies in which potassium excretion rates and serum potassium levels were measured, we used samples that had been collected from members of the cohort who had agreed to provide an overnight urine sample and a blood sample.…”