Longitudinal Correlates of Change in Blood Pressure in Adolescent Girls

S. R. Daniels, R. P. McMahon, E. Obarzanek, M. A. Waclawiw, S. L. Similo, F. M. Biro, G. B. Schreiber, S. Y. S. Kimm, J. A. Morrison, B. A. Barton
1998 Hypertension  
The objective of this study was to assess the longitudinal changes in blood pressure in black and white adolescent girls and evaluate potential determinants of changes in blood pressure, including sexual maturation and body size. A total of 1213 black and 1166 white girls, ages 9 or 10 years at study entry, were followed up through age 14 with annual measurements of height, weight, skinfold thickness, stage of sexual maturation, systolic and diastolic blood pressures, and other cardiovascular
more » ... sk factors. Average blood pressures in black girls were generally 1 to 2 mm Hg higher than in white girls of similar age over the course of the study. Age, race, stage of sexual maturation, height, and body mass index (kg/m 2 ) were all significant univariate predictors of systolic and diastolic blood pressures in longitudinal regression analyses. Black girls had a significantly smaller increase in blood pressure for a given increase in body mass index compared with white girls. The predicted increases in blood pressure per unit increase in body mass index (mm Hg per kg/m 2 ) were as follows: systolic, 0.65Ϯ0.04 in whites and 0.52Ϯ0.04 in blacks (PϽ.001); diastolic fourth Korotkoff phase, 0.31Ϯ0.04 in whites and 0.15Ϯ0.03 in blacks (PϽ.001); and diastolic fifth Korotkoff phase, 0.31Ϯ0.05 in whites and 0.16Ϯ0.04 in blacks (PϽ.001). Understanding of the determinants of the racial differences in blood pressure could provide the rationale for future interventions to reduce the excess cardiovascular mortality in black compared with white women. (Hypertension. 1998;31[part 1]:97-103.) Key Words: blood pressure Ⅲ race Ⅲ obesity Ⅲ adolescents E levated blood pressure is more prevalent in black compared with white women at every age from 18 to 74 years. 1 This finding is one factor that may significantly contribute to the increased risk of earlier cardiovascular disease morbidity and mortality observed in black women. 2 However, the timing of the onset and course of racial differences in blood pressure is uncertain. The majority of investigations of blood pressure differences by race in childhood and adolescence have been cross-sectional in design. Some of these studies have found higher blood pressure in black children, 3,4 others have found no difference, 5,6 and still other studies have found higher blood pressure in white children. 7, 8 The evaluation of potentially important covariates of blood pressure, including age, height, weight, obesity, and sexual maturation, in these studies has been variable. The evaluation of obesity is particularly important in this regard because obesity has been shown to be a risk factor for blood pressure elevation, and some studies have suggested a differential effect of obesity on blood pressure between white and black adults. 9 -11 The NGHS is a prospective cohort study designed to evaluate the emergence of differences in obesity and cardiovascular risk factors during adolescence in black and white girls. The purpose of the present report is to describe the longitudinal changes in blood pressure in black and white girls from age 9 to age 14 years and to determine the presence and persistence of racial differences in blood pressure in the cohort over time. The determinants of longitudinal change in systolic and diastolic blood pressure over time and the presence of racial differences in the growth-related determinants of change were also evaluated. by guest on July 22, 2018 http://hyper.ahajournals.org/ Downloaded from Figure 3. A, Mean systolic blood pressure by BMI (kg/m 2 ) category and race for visit 3 (ages 11 to 12 years). B, Mean diastolic (K4) blood pressure by BMI (kg/m 2 ) category and race for visit 3 (ages 11 to 12 years). C, Mean diastolic (K5) blood pressure by BMI (kg/m 2 ) category and race for visit 3 (ages 11 to 12 years).
doi:10.1161/01.hyp.31.1.97 pmid:9449398 fatcat:ugxlor6vmzav3faikm6egcpyva