Race and diurnal blood pressure patterns. A review and meta-analysis.
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Investigators have reported variable findings regarding the role of race in diurnal blood pressure patterns. We performed a review and meta-analysis of this literature to identify the overall effect of race on circadian blood pressure patterns. Eighteen studies involving 2852 participants were reviewed. Meta-analyses were conducted using effect sizes calculated from the data provided directly in the study reports. Separate meta-analyses were conducted on effect sizes for differences between blacks and whites in daytime and nighttime systolic and diastolic blood pressure and nocturnal dip in systolic and diastolic blood pressure. To evaluate discrepancies in findings from studies involving American versus non-American blacks, overall meta-analyses as well as within-subset meta-analyses of black/white differences were conducted for comparisons involving American and non-American blacks. Results of overall meta-analyses indicate that blacks experience higher levels of systolic and diastolic blood pressure, both at night and during the day. These differences were significantly greater at night than during the day (P<0.05). Results of within-subset analyses involving American blacks mirrored those for all black/white comparisons, except that the effect of race on nocturnal dip, ie, that American blacks experienced less of a dip in both systolic and diastolic blood pressure at night, was significant (P<0.05). In contrast, the effect of race on nocturnal dip was not significant for comparisons involving non-American blacks. These results suggest a consistent difference in the chronobiology of blood pressure, particularly in American blacks. (+info)
Descriptive epidemiology of blood pressure response to change in body position. The ARIC study.
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The epidemiology of a common measure of cardiovascular reactivity, the change in systolic blood pressure (DeltaSBP) from the supine to the standing position, is described in a cohort of 13 340 men and women aged 45 to 65 years enrolled in the Atherosclerosis Risk in Communities (ARIC) Study. The distribution of DeltaSBP was found to be symmetrical and unimodal, with a mean value near zero (-0.45 mm Hg). The range of DeltaSBP was from -63.2 to 54.3 mm Hg, and the standard deviation was 10.8. Stratification of DeltaSBP by race and gender shows a slight shift in distribution toward higher values for black men and women. DeltaSBP was categorized into deciles. Participants in the top 30% and bottom 30% of the distribution were compared with individuals in the middle 40% of the distribution, who had little or no change in SBP on standing. Participants in the bottom 30% (ie, SBP decreased on standing) were significantly older, had a greater prevalence of hypertension and peripheral vascular disease, had higher values of SBP, and had more cigarette-years of smoking. Among participants in the top 30% (ie, SBP increased on standing), a significantly larger proportion were black, mean seated SBP was higher, and the predicted risk of developing coronary heart disease after 8 years was greater. The response of SBP to change in posture showed considerable variability in a population sample of middle-aged adults. Cardiovascular morbidity, sociodemographic factors, and cigarette smoking were associated with the magnitude and direction of the postural change. (+info)
Anatomical differences in the psoas muscles in young black and white men.
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The anatomy of the psoas major muscle (PMA) in young black and white men was studied during routine autopsies. The forensic autopsies included 44 fresh male cadavers (21 black, 23 white) with an age span of 14 to 25 y. The range for weight was 66-76 kg and for height 169-182 cm. The PMA was initially measured in its entire length before measuring the diameter and circumference at each segmental level (L1-S1). At each segmental level, the calculated anatomical cross-sectional area (ACSA) was more than 3 times greater in the black group compared with the white (P < 0.001). The psoas minor muscle (PMI) was absent in 91% of the black subjects, but only in 13% of the white subjects. These data show that the PMA is markedly larger in black than white subjects. The marked race specific difference in the size of the PMA may have implications for hip flexor strength, spine function and race specific incidence in low back pathology, and warrants further investigation. (+info)
Obesity: does it occur in African children in a rural community in South Africa?
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BACKGROUND: Total body fatness and a centripetal fat patterning are recognized as risk indicators of cardiovascular disease in adulthood. In this study, the development of these risk factors in rural South African children during the preschool years and first years of formal schooling is explored. METHOD: The initial cross-sectional data from the Ellisras Longitudinal Investigations in Rural Community Children Project, ongoing since 1996, were used, involving 684 boys and 652 girls, aged 3-10 years, in the Ellisras rural community. Overweight was measured using the body mass index (BMI) (kg/m2). Overfatness was based on the sum of the triceps and subscapular skinfold thicknesses. A centripetal fat patterning was measured by the sum of trunk skinfolds relative to limb skinfolds and the ratio of the subscapular to triceps skinfold. Further, the ratio of the subscapular to supraspinale skinfold was used as an indicator of lower body fat patterning. The 85th percentiles of the NHANES III were used as cutoff values for overweight, overfatness and a centripetal fat patterning. RESULTS: At ages 7 and 8 years, mean BMI was statistically significantly higher in males compared to females (P < 0.05). The log transformed supraspinale skinfold thickness was larger in females compared to males at ages 4-7 years; the log transformed subscapular skinfold was larger in girls compared to boys aged 7-10 years. Less clear patterns were found for the extremity skinfolds and the skinfold ratios. Very few children (0-2.5% in males and 0-4.3% in females) had BMI values above the NHANES III 85th percentiles, indicating a very low prevalence of overweight children in the area. About 15% of the males showed overfatness at ages 3-4 years, while low prevalence was found at older ages. CONCLUSION: Few Ellisras rural children had above normal values for BMI, indicating a low prevalence of obesity in this population. In the 3- and 4-year-old group more subjects were found to have excessive fat, as indicated by the sum of the triceps and subscapular skinfold thicknesses. (+info)
Molecular and genetic damage from environmental tobacco smoke in young children.
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To assess the risks of early life exposure to environmental tobacco smoke (ETS), we tested whether four biomarkers in peripheral blood were associated with home ETS exposure in Hispanic and African-American children. The biomarkers included cotinine (a metabolite of nicotine) and three indicators of molecular and genetic damage from mutagens/carcinogens, protein adducts formed by the carcinogens 4-aminobiphenyl (4-ABP) and polycyclic aromatic hydrocarbons (PAHs), and sister chromatid exchanges (SCEs). We also explored possible ethnic differences in biomarkers. The study cohort comprised 109 Hispanic and African-American preschool children (1-6 years of age). Plasma cotinine was analyzed by gas chromatography, 4-ABP-hemoglobin adducts by gas chromatography-mass spectroscopy, PAH-albumin adducts by ELISA, and SCEs by cytogenetic techniques. Data on the amount of smoking by mothers (average 10.5 cigarettes per day) and other household members and regular visitors (average 6.5 cigarettes per day) were obtained by interview-administered questionnaires. Cotinine, 4-ABP-hemoglobin adducts, and PAH-albumin were significantly higher (P < 0.05) in the ETS-exposed children compared with the unexposed. SCEs were marginally higher (P = 0.076). African-American children had higher levels of cotinine (P = 0.059) and PAH-albumin (P = 0.02) than Hispanic children, after controlling for exposure to ETS. These results indicate molecular and genetic damage in minority children with (+info)
Urinary excretion of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in White, African-American, and Asian-American men in Los Angeles County.
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Meats, such as beef, pork, poultry, and fish, cooked at high temperatures produce heterocyclic aromatic amines, which have been implicated indirectly as etiological agents involved in colorectal and other cancers in humans. This study examined the urinary excretion of a mutagenic/carcinogenic heterocyclic aromatic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), among 45 African-American, 42 Asian-American (Chinese or Japanese), and 42 non-Hispanic white male residents of Los Angeles who consumed an unrestricted diet. Total PhIP (free and conjugated) was isolated from overnight urine collections, purified by immunoaffinity chromatography, and then quantified by high-pressure liquid chromatography combined with electrospray ionization mass spectrometry. Geometric mean levels of PhIP in Asian-Americans and African-Americans were approximately 2.8-fold higher than in whites. The urinary excretion levels of PhIP were not associated with intake frequencies of any cooked meat based on a self-administered dietary questionnaire, in contrast to our earlier finding (Ji et al., Cancer Epidemiol. Biomark. Prev., 3: 407-411, 1994) of a positive and statistically significant association between bacon intake and the urinary level of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) among this same group of study subjects. Although there is a statistically significant association between urinary levels of PhIP and MeIQx (2-sided P = 0.001), 10 subjects (8%) displayed extreme discordance between urinary PhIP and MeIQx levels. Several factors, including variable contents of heterocyclic aromatic amines in food, enzymic and interindividual metabolic differences, and analytical methodology determine the degree of concordance between the urinary excretion levels of PhIP and MeIQx. Accordingly, urinary excretion levels of a single heterocyclic aromatic amine can only serve as an approximate measure of another in estimating exposure to these compounds in humans consuming unrestricted diets. (+info)
The effect of congenital anomalies on mortality risk in white and black infants.
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OBJECTIVES: This population-based study examined the effect of all major congenital anomalies on the mortality of White and Black infants by infant sex, birthweight, gestational age, and lethality of the anomaly. The study also determined the total contribution of anomalies to infant mortality. METHODS: California Birth Defects Monitoring Program data were merged with linked birth-death files for 278,646 singleton non-Hispanic White and Black infants born in 1983 through 1986. Malformed infants were compared with nonmalformed infants to determine the effect of anomalies on mortality. RESULTS: The presence of any congenital anomaly increased mortality 9.0-fold (95% CI = 7.3, 11.1) for Black infants and 17.8-fold (95% CI = 16.2, 19.6) for White infants. Even "non-lethal" anomalies increased mortality up to 8.9-fold. Overall, anomalies contributed to 33% of White infant deaths, to 19% of Black infant deaths, and to over 60% of deaths among Black and White neonates weighing over 1499 g. CONCLUSIONS: The contribution of congenital anomalies to mortality of both low- (< 2500 g) and normal-birth-weight infants is substantially higher than previously estimated, representing a large public health problem for both Black and White infants. (+info)
Simple tandem repeat polymorphisms in the neuronal nitric oxide synthase gene in different ethnic populations.
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Allelic frequencies of a CA dinucleotide repeat in exon 29 and an intronic AAT trinucleotide repeat in the neuronal nitric oxide synthase (NOS1) gene were determined by simple sequence length polymorphism (SSLP) in 305 American-Caucasian and 105 African-American healthy subjects. There were highly significant differences in allele frequencies between the two ethnically diverse study populations. (+info)