Racial Differences In Blood Pressure Research Articles

Racial Differences in Blood Pressure and Autonomic Recovery Following Acute Supramaximal Exercise in Women.

Despite the growing popularity of high-intensity anaerobic exercise, little is known about the acute effects of this form of exercise on cardiovascular hemodynamics or autonomic modulation, which might provide insight into the individual assessment of responses to training load. The purpose of this study was to compare blood pressure and autonomic recovery following repeated bouts of acute supramaximal exercise in Black and White women. A convenience sample of twelve White and eight Black young, healthy women were recruited for this study and completed two consecutive bouts of supramaximal exercise on the cycle ergometer with 30 min of recovery in between. Brachial and central aortic blood pressures were assessed by tonometry (SphygmoCor Xcel) at rest and 15-min and 30-min following each exercise bout. Central aortic blood pressure was estimated using brachial pressure waveforms and customized software. Autonomic modulation was measured in a subset of ten participants by heart-rate variability and baroreflex sensitivity. Brachial mean arterial pressure and diastolic blood pressure were significantly higher in Blacks compared to Whites across time (race effect, p = 0.043 and p = 0.049, respectively). Very-low-frequency and low-frequency bands of heart rate variability, which are associated with sympathovagal balance and vasomotor tone, were 22.5% and 24.9% lower, respectively, in Blacks compared to Whites (race effect, p = 0.045 and p = 0.006, respectively). In conclusion, the preliminary findings of racial differences in blood pressure and autonomic recovery following supramaximal exercise warrant further investigations of tailored exercise prescriptions for Blacks and Whites.

Association of West African ancestry and blood pressure control among African Americans taking antihypertensive medication in the Jackson Heart Study.

African Americans have a wide range of continental genetic ancestry. It is unclear whether racial differences in blood pressure (BP) control are related to ancestral background. The authors analyzed data from the Jackson Heart Study, a cohort exclusively comprised of self-identified African Americans, to assess the association between estimated West African ancestry (WAA) and BP control (systolic and diastolic BP<140/90mmHg). Three nested modified Poisson regression models were used to calculate prevalence ratios for BP control associated with the three upper quartiles, separately, vs the lowest quartile of West African ancestry. The authors analyzed data from 1658 participants with hypertension who reported taking all of their antihypertensive medications in the previous 24hours. WAA was estimated using 389 ancestry informative markers and categorized into quartiles (Q1: <73.7%, Q2: >73.7%-81.0%, Q3: >81.0%-86.3%, and Q4: >86.3%). The proportion of participants with controlled BP in the lowest-to-highest WAA quartile was 75.2%, 76.1%, 76.6%, and 74.4%. The prevalence ratios (95% CI) for controlled BP comparing Q2, Q3, and Q4 to Q1 of WAA were 1.00 (0.93-1.08), 1.02 (0.94-1.10), and 0.99 (0.91-1.07), respectively. Among African Americans in the Jackson Heart Study taking antihypertensive medication, BP control rates did not differ across quartiles of WAA.

Racial Disparities in Blood Pressure Trajectories of Preterm Children: The Role of Family and Neighborhood Socioeconomic Status.

Racial disparities in cardiovascular disease mortality in the United States remain substantial. However, the childhood roots of these disparities are not well understood. In the current study, we examined racial differences in blood pressure trajectories across early childhood in a sample of African-American and European-American low-birth-weight preterm infants. Family and neighborhood socioeconomic status (SES), measured at baseline, were also examined as explanations for subsequent group disparities. Analyses focused on 407 African-American and 264 European-American children who participated in the Infant Health and Development Program, a US longitudinal study of preterm children born in 1985. Blood pressure was assessed on 6 occasions between the ages of 24 and 78 months, in 1987-1992. Across this age range, the average rate of change in both systolic and diastolic blood pressure was greater among African-American children than among European-American children. Neighborhood SES explained 29% and 24% of the racial difference in the average rate of change in systolic and diastolic blood pressure, respectively, whereas family SES did not account for group differences. The findings show that racial differences in blood pressure among preterm children emerge in early childhood and that neighborhood SES accounts for a portion of racial disparities.

Abstract P156: Health Literacy and Health Behaviors Associated with Racial Disparities in Blood Pressure

Introduction: Racial disparity in cardiovascular disease has prompted efforts to improve cardiovascular outcomes through patient education and health behavior promotion. However, little is known about the long-term effects of health literacy and health behaviors on cardiovascular disease outcomes. Hypothesis: This study aims to explore whether racial differences in long-term blood pressure outcomes are associated with baseline levels of health literacy, mediated through longitudinal patterns of health behaviors. Methods: This study used a prospective cohort from the Coronary Artery Risk Development in Young Adults (CARDIA) project, funded by NHLBI. Blood pressure was measured by trained CARDIA researchers at seven examinations between 1985 and 2005. Self-reported health behaviors (including smoking, binge drinking, overweight and sedentary lifestyle) were obtained at each examination. Cardiovascular health literacy was assessed as part of the 1990 observation. We used growth curve modeling to explore racial disparities in blood pressure and to examine if blood pressure outcomes could be explained by participants’ health literacy and their health behavior change. This study included 3,546 CARDIA study participants who remained in the most recent examination at year 2005, with 47% African Americans and 43% males. Results: Racial disparities were observed in participants’ initial blood pressure, blood pressure progression rate, health literacy and health behaviors. African Americans had higher blood pressure at baseline (systolic: 109 vs. 105; diastolic: 70 vs. 67 P&lt;0.0001) and greater increases over time. Caucasians had a higher health literacy score (4 vs. 3.5 P&lt;0.0001) and reported fewer risk behaviors on average. There was a positive relationship between health literacy, education attainment, parents’ education attainment, family income, having health insurance and having fewer risk behaviors. Participants with fewer risk behaviors had lower blood pressure. Blood pressure improved in years with fewer risk behaviors. Higher baseline health literacy was associated with having fewer risk behaviors in the following fifteen years. Overall, the results indicated that blood pressure outcomes were indirectly influenced by baseline health literacy through longitudinal patterns of risk behaviors. This relationship was stronger in Caucasians. Conclusions: This study suggests that racial differences in blood pressure are associated with both health literacy and health behaviors. In response to these findings, important gaps in hypertension preventive care and health behavior promotion should be identified and addressed through efforts to improve cardiovascular health literacy. For minority and high risk populations, multifaceted approaches in addition to patient education may be needed to initiate behavior change.

Poor Long-Term Blood Pressure Control After Intracerebral Hemorrhage

Hypertension is the most important risk factor associated with intracerebral hemorrhage. We explored racial differences in blood pressure (BP) control after intracerebral hemorrhage and assessed predictors of BP control at presentation, 30 days, and 1 year in a prospective cohort study. Subjects with spontaneous intracerebral hemorrhage were identified from the DiffErenCes in the Imaging of Primary Hemorrhage based on Ethnicity or Race (DECIPHER) Project. BP was compared by race at each time point. Multivariable linear regression was used to determine predictors of presenting mean arterial pressure, and longitudinal linear regression was used to assess predictors of mean arterial pressure at follow-up. A total of 162 patients were included (mean age, 59 years; 53% male; 77% black). Mean arterial pressure at presentation was 9.6 mm Hg higher in blacks than whites despite adjustment for confounders (P=0.065). Fewer than 20% of patients had normal BP (<120/80 mm Hg) at 30 days or 1 year. Although there was no difference at 30 days (P=0.331), blacks were more likely than whites to have Stage I/II hypertension at 1 year (P=0.036). Factors associated with lower mean arterial pressure at follow-up in multivariable analysis were being married at baseline (P=0.032) and living in a facility (versus personal residence) at the time of BP measurement (P=0.023). Long-term BP control is inadequate in patients after intracerebral hemorrhage, particularly in blacks. Further studies are needed to understand the role of social support and barriers to control to identify optimal approaches to improve BP in this high-risk population.

Racial Differences in Blood Pressure after Exercise in Young Individuals

Hypertension prevalence is higher in Caucasians (CA) than in Chinese (CH), and high blood pressure (BP) is associated with greater cardiovascular disease risk. However, little is known about the response of BP to an acute bout of exercise.18 college age young CH (height: 170 ± 2 cm, weight: 63 ± 3 kg, BMI: 21.8 ± 0.6 kg/m2) and 19 CA (height: 171 ± 3 cm, weight: 73 ± 4 kg, BMI: 24.7 ± 0.8 kg/m2) underwent measures of BP and central (carotid‐femoral) and leg (carotid‐femoral) pulse‐wave velocity (PWV) before, 15 min, and 30 min after a graded maximal aerobic exercise test (EX) on a stationary bike by applanation tonometry.Diastolic BP was increased in CA but decreased in CH following exercise (CH: from 64 ± 2 to 61 ± 3 to 62 ± 2 mmHg; CA from 65 ± 2 to 67 ± 2 to 67 ± 2 mmHg, race by time interaction, p&lt;0.05). Systolic BP changed with time (CH: from 112 ± 3 to 115 ± 4 to 111 ± 3 mmHg; CA from 118 ± 3 to 121 ± 3 to 116 ± 3 mmHg, p&lt;0.05), but no racial differences. A significant time by race interaction was found in leg PWV (CH: from 8.5 ± 0.4 to 6.9 ± 0.4 to 7.3 ± 0.4 m/s; CA: from 8.6 ± 0.4 to 8.3 ± 0.3 to 8.0 ± 0.3m/s, p&lt; 0.05). Central PWV was not statistically different between CA and CH. Statistically adjusting for BMI did not change these findings.This is the first study to note racial differences in the BP and peripheral arterial response to exercise, suggesting increased BP in young CA and differences in peripheral arterial stiffening following exercise compared to CH.

Vitamin D as a Mediator of Racial Differences in Blood Pressure

Vitamin D as a Mediator of Racial Differences in Blood Pressure

Racial and ethnic differences in hypertension

Hypertension is a major cause of disease burden in all racial and ethnic groups and in both developing and developed regions and countries. Much of the racial and ethnic disparity in cardiovascular outcomes can be attributed to the excess burden of hypertension. Racial and ethnic differences in blood pressure occur because of biology and sociology. Causes of racial differences in blood pressure likely begin early in life and reflect the complex relationship of these gene and environment interactions. Hypertension treatment and control remain less than optimal worldwide, and awareness is still a problem in many racial and ethnic groups. Instituting lifestyle changes for the primary prevention and treatment of hypertension among the general population would decrease prevalence and be effective in eliminating many racial and ethnic differences. This review highlights racial and ethnic differences in the prevalence and incidence of hypertension and identifies contributing factors associated with these differences.

Racial Differences in Blood Pressure Control: Potential Explanatory Factors

The objective of the study was to identify potential explanatory factors for racial differences in blood pressure (BP) control. The design of the study was a cross-sectional study The study included 608 patients with hypertension who were either African American (50%) or white (50%) and who received primary care in Durham, NC. Baseline data were obtained from the Take Control of Your Blood pressure study and included clinical, demographic, and psychosocial variables potentially related to clinic BP measures. African Americans were more likely than whites to have inadequate baseline clinic BP control as defined as greater than or equal to 140/90 mmHg (49% versus 34%; unadjusted odds ratio [OR] 1.8; 95% confidence interval [CI] 1.3-2.5). Among factors that may explain this disparity, being older, reporting hypertension medication nonadherence, reporting a hypertension diagnosis for more than 5 years, reporting high levels of stress, being worried about hypertension, and reporting an increased number of medication side effects were related to inadequate BP control. In adjusted analyses, African Americans continue to have poor BP control relative to whites; the magnitude of the association was reduced (OR = 1.5; 95% CI 1.0-2.1). Medication nonadherence, worries about hypertension, and older age (>70) continued to be related to poor BP control. In this sample of hypertensive patients, there were a number of factors associated with poor BP control that partially explained the observed racial disparity in hypertension control including age, medication nonadherence, and worry about BP. Medication nonadherence is of particular interest because it is a potentially modifiable factor that might be used to reduce the racial disparity in BP control.

Letter by Wexler and Feldman Regarding Article, “Ethnic and Gender Differences in Ambulatory Blood Pressure Trajectories: Results From a 15-Year Longitudinal Study in Youth and Adults”

HomeCirculationVol. 115, No. 20Letter by Wexler and Feldman Regarding Article, “Ethnic and Gender Differences in Ambulatory Blood Pressure Trajectories: Results From a 15-Year Longitudinal Study in Youth and Adults” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBLetter by Wexler and Feldman Regarding Article, “Ethnic and Gender Differences in Ambulatory Blood Pressure Trajectories: Results From a 15-Year Longitudinal Study in Youth and Adults” Randy Wexler David Feldman Randy WexlerRandy Wexler Department of Clinical Family Medicine, The Ohio State University, Columbus, Ohio Search for more papers by this author David FeldmanDavid Feldman Department of Heart Failure and Cardiac Transplantation, The Ohio State University College of Medicine and Public Health, Columbus, Ohio Search for more papers by this author Originally published22 May 2007https://doi.org/10.1161/CIRCULATIONAHA.106.685776Circulation. 2007;115:e477To the Editor:The research presented by Wang et al1 is an important contribution toward understanding and reducing disparities in health care in general and hypertension in particular. Although we agree with their conclusion that “further work will be needed to determine specific risk factors, both genetic and environmental,” we hope we will not forget that the explanation of a problem does not always equal a solution.As pointed out in the editorial by Jones and Hall,2 “the challenges to understanding the science of racial differences and disparities in cardiovascular disease are substantial,” and the “study by Wang et al makes an important contribution to our understanding of racial differences in blood pressure.” Such information is vitally important, but it will provide very minimal benefit to African American patients unless we can address some of the cultural differences that also exist.Many African Americans continue to be wary of the healthcare system, and with good reason. The research conducted at Tuskegee still resonates within the African American community. As such, any interventions developed on the basis of genetic or environmental risk must also address the cultural gap that exists in some African American communities between perceptions of hypertension and the healthcare system. This includes the beliefs that (1) foods such as pork cause hypertension,3 (2) pharmaceutical companies use patients to test medications,4 (3) physicians use authoritarian and ethnically inappropriate communication patterns,5 and (4) African Americans expect to be active participants in their care even though they may not be treated as such by physicians.6Unless we work to overcome the cultural differences (both real and imagined) that also exist within health care, any treatment(s) for hypertension developed from a better understanding of genetic and environmental influences will not yield the hoped-for results.DisclosuresNone.1 Wang X, Poole JC, Treiber FA, Harshfield GA, Hanevold CD, Harold S. Ethnic and gender differences in ambulatory blood pressure trajectories: results from a 15-year longitudinal study in youth and adults. Circulation. 2006; 114: 2780–2787.LinkGoogle Scholar2 Jones DW, Hall JE. Racial and ethnic differences in blood pressure: biology and sociology. Circulation. 2006; 114: 2757–2759.LinkGoogle Scholar3 Wilson RP, Freeman A, Kazda MJ, Andrews TC, Berry L, Vaeth PAC, Victor RG. Lay beliefs about high blood pressure in a low- to middle-income urban African American community: an opportunity for improving hypertension control. Am J Med. 2002; 112: 26–30.CrossrefMedlineGoogle Scholar4 Lukoschek P. African Americans’ beliefs and attitudes regarding hypertension and its treatment: a qualitative study. J Health Care Poor Underserved. 2003; 14: 566–587.CrossrefMedlineGoogle Scholar5 Merick PC. Rethinking the target corollary: the effects of social distance, perceived exposure, and perceived predispositions on first-person and third person perceptions. Communic Res. 2005; 32: 822–843.CrossrefGoogle Scholar6 Ogedegbe G, Mancuso CA, Allegrante JP. Expectations of blood pressure management in hypertensive African American patients: a qualitative study. J Natl Med Assoc. 2004; 96: 442–449.MedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Wexler R, Elton T, Pleister A and Feldman D (2009) Barriers to Blood Pressure Control as Reported by African American Patients, Journal of the National Medical Association, 10.1016/S0027-9684(15)30947-0, 101:6, (597-603), Online publication date: 1-Jun-2009. May 22, 2007Vol 115, Issue 20 Advertisement Article InformationMetrics https://doi.org/10.1161/CIRCULATIONAHA.106.685776PMID: 17515472 Originally publishedMay 22, 2007 PDF download Advertisement SubjectsBehavioral/Psychosocial TreatmentEthics and PolicyHypertension

Why Is Hypertension More Common in African Americans?

Why Is Hypertension More Common in African Americans?

Ultraviolet Light May Contribute to Geographic and Racial Blood Pressure Differences

Ultraviolet Light May Contribute to Geographic and Racial Blood Pressure Differences

Ultraviolet light may contribute to geographic and racial blood pressure differences.

Mean systolic and diastolic pressures and the prevalence of hypertension vary throughout the world. Published data suggest a linear rise in blood pressure at increasing distances from the equator. Similarly, blood pressure is higher in winter than summer. Blood pressure also is affected by variations in skin pigmentation. Altered calcium, vitamin D, and parathyroid hormone status is associated with hypertension and may vary with latitude and season. Since changes in UV light affect vitamin D and parathyroid hormone status and UV light intensity are influenced by seasonal change and latitude, these disparate observations suggest an association between blood pressure and ultraviolet light. This discussion presents the hypothesis that reduced epidermal vitamin D3 photosynthesis associated with high skin melanin content and/or decreased UV light intensity at distances from the equator, alone or when coupled with decreased dietary calcium and vitamin D, may be associated with reduced vitamin D stores and increased parathyroid hormone secretion. These changes may stimulate growth of vascular smooth muscle and enhance its contractility by affecting intracellular calcium, adrenergic responsiveness, and/or endothelial function. Thus, UV light intensity and efficiency of epidermal vitamin D3 photosynthesis may contribute to geographic and racial variability in blood pressure and the prevalence of hypertension.

Sexual maturation and racial differences in blood pressure in girls: The National Heart, Lung, and Blood Institute Growth and Health Study

OBJECTIVE: To evaluate racial differences in blood pressure in girls aged 9 to 10 years in the National Heart, Lung, and Blood Institute Growth and Health Study (NGHS) and to evaluate the extent to which racial differences in blood pressure are explained by other factors, including sexual maturation and body size. METHODS: The NGHS enrolled 539 black and 616 white girls aged 9 years, and 674 black and 550 white girls aged 10 years. Racial differences in blood pressure were examined. Relationships of stage of sexual maturation, height, and skinfold thickness with systolic and diastolic blood pressure were evaluated by multiple regression analysis. RESULTS: The black girls had significantly higher systolic (102.0 ± 8.90 vs 100.5 ± 9.42 mm Hg, p <0.001) and diastolic (58.0 ± 12.0 vs 56.5 ± 12.51 mm Hg, p <0.01) blood pressures than the white girls. The black girls were also more advanced in sexual maturation and were taller (142.9 ± 7.94 vs 139.6 ± 7.05, p <0.001) and heavier (39.6 ± 11.24 vs 35.3 ± 8.73 kg, p <0.001) than the white girls. Both systolic and diastolic blood pressure were significantly correlated with level of maturation, height, weight, and sum of skinfolds. Stage of maturation was found to account for the difference in blood pressure between black girls and white girls. In a multiple regression analysis, controlling for height (for diastolic blood pressure) and for both height and sum of skinfolds (for systolic blood pressure) eliminated the effects of race and stage of maturation on blood pressure. CONCLUSION: Racial differences in blood pressure were observed for 9- and 10-year-old girls and are explained by the fact that black girls were more mature than white girls. The effect of sexual maturation on blood pressure appears to operate through height and body fat. The effect of obesity may be more important for systolic than for diastolic blood pressure. Continuation of racial differences in blood pressure may result in a higher prevalence of hypertension for black women. (J P EDIATR 1996;129:208-13)

A survey of blood pressure distribution in Pygmy and Bantu populations in Cameroon.

A blood pressure survey was performed in isolated Pygmy communities and Bantu population samples living either in close relationship with the Pygmies or in separate areas within the same region. The Pygmies are still living as hunter-gatherers, whereas the Bantus rely on agriculture for food provision. Mean blood pressures in Pygmies were 130/85 mm Hg in males and 126/80 mm Hg in females and in Bantus were 137/87 mm Hg in males and 136/84 mm Hg in females. In spot urine the mean urinary sodium concentration was higher in Bantus than Pygmies (86 versus 37 mmol/L in males; 95 versus 56 mmol/L in females). In the total population urinary potassium concentration was very high (150 mmol/L), calcium concentration very low (0.4 mmol/L), and urea concentration low (6.9 g/L). After adjustment for age, height, weight, and sex, no racial differences in blood pressure were present. Blood pressure increased with age but body mass index did not. Diastolic pressure correlated significantly but negatively with urinary sodium in multiple regression analysis. Our study demonstrates that blood pressure increases with age in hunter-gatherer populations on a low to moderately high sodium diet in the presence of a low urinary excretion of calcium coupled with a low protein intake.

The serum angiotensinogen concentration and variants of the angiotensinogen gene in white and black children.

The T235 allele of the angiotensinogen gene (AGT) has been associated with hypertension. Blood pressure increases faster over time in black children than in white children, and in adults hypertension is more prevalent in blacks. We sought evidence for a role for angiotensinogen to contribute to racial differences in blood pressure in a study of 148 white and 62 black normotensive children (mean age, 14.8 yr). The frequency of the T235 allele was 0.81 in blacks and 0.42 in whites (chi 2 = 77.3, P = 0.0001). The mean angiotensinogen level was 19% higher in blacks than in whites (P = 0.0001 for males, P = 0.004 for females). Genotype was positively related to serum angiotensinogen in white children (P = 0.0001 for males, P = 0.004 for females), but a similar relationship was absent in blacks where the frequency of M235 may have been too low to discern an association. Longitudinal blood pressure (measured twice yearly) adjusted for body mass index showed a marginally significant relationship to the angiotensinogen level (P = 0.07). An independent relationship of serum angiotensinogen with body mass index (P = 0.0001) and race (P = 0.0003) was also observed. In summary, T235 was more frequent, and the level of angiotensinogen was higher in blacks than in whites. Such a racial difference in the renin-angiotensin system may contribute to the disparity in blood pressure levels of white and black young people.

The Use of Ambulatory Blood Pressure Monitoring in the Evaluation of Racial Differences in Blood Pressure

Ethnic differences in 24h blood pressure profiles exist, and 24h ambulatory blood pressure monitoring shows that blacks have a higher nocturnal blood pressure associated with a small diurnal change in pressure. Studies in adolescents suggest that these diurnal differences antedate adulthood. Nocturnal blood pressure may be independently important in the pathogenesis of left ventricular hypertrophy.

Racial differences in blood pressure among urban adolescents

The purpose of this study was to determine if there are racial differences in the blood pressure patterns among urban adolescents. Blood pressure (BP) was measured according to Task Force guidelines in health-screening and education sessions conducted in urban public and parochial high schools. The prevalence of BP ≥ 95th% (HBP) on initial screening was determined in a population of 3,349 students. Differences in prevalence of HBP among race, sex, and age groups were tested for significance by χ 2 analysis. The overall prevalence of HBP in this urban adolescent population was 8.1%. Significant race differences were present in females (blacks = 6.6% versus non-Hispanics = 2.9%, p < 0.01). Within the black females, HBP occurred more frequently among the girls attending predominantly black public schools (7.7%) compared to an interracial parochial school (2.0%) p < 0.001. This difference could not be explained by weight, height, or the occurrence of obesity. The observed BP differences within black females, by school, may reflect a family-environment effect on cardiovascular risk.

Adrenal androgen excretion during adrenarche. Relation to race and blood pressure.

We have previously shown that black children have higher blood pressures than white children. In the present study, we examined whether a possible racial difference in adrenal androgen production during adrenarche might contribute to the racial disparity in blood pressure. Adrenal androgen production was estimated from urinary excretion of adrenal androgen metabolites that showed cross-reactivity with antisera to dehydroepiandrosterone sulfate (DHEA-S). Urine samples were collected overnight in 798 children, one third of whom were black. Analyses were performed for two different age groups, less than 10 years and 10 years or more of age. In children less than 10 years of age, adrenal androgen excretion rates were 17% higher in blacks than in whites (p = 0.0099); adrenal androgen excretion rates tended to be higher in older black children as well, but differences here were not statistically significant. Adrenal androgen excretion rates were positively correlated with diastolic blood pressure in the older age group only (p = 0.014). However, when the relation of race to blood pressure was examined along with adrenal androgen excretion adjusted for age, sex, and weight, race remained an independent contributor to the level of blood pressure, suggesting that a difference in adrenal androgens could not explain the racial differences in blood pressure. In summary, black children produced more adrenal androgen, but this did not explain their higher blood pressures. In older children, where adrenal androgen excretion rates were higher, diastolic blood pressure and adrenal androgen excretion were positively related, suggesting that adrenal androgens participate in establishing the level of blood pressure in young people.

Responses to ergometer exercise in a healthy biracial population of children

To determine normal values for the exercise variables heart rate, blood pressure, maximal workload, physical working capacity index, J point displacement, and ST segment slope, we stress tested 405 healthy children. We analyzed the data for four body surface area-determined groups, to discover whether there were any racial differences between healthy white children and black children. There were numerous racial differences in blood pressure, maximal workload, and physical working capacity index; there were no differences in the heart rate values. The incidence of false-positive J point displacement was less than or equal to 3% when the PR isoelectric line method was used. The ST segment slope in healthy children was always greater than zero at maximal exercise. Thus, norms for exercise variables must be expressed in relation to both sex and race. The nomograms presented in this report provide an easy-to-use set of normative data for cycle ergometer stress testing in children.