Cumulative psychosocial factors are associated with cardiovascular disease risk factors and management among African Americans in the Jackson Heart Study.

BACKGROUND: Racial disparities in cardiovascular disease (CVD) have been attributed in part to negative psychosocial factors. Prior studies have demonstrated associations between individual psychosocial factors and CVD risk factors, but little is known about their cumulative effects. METHODS: Using the Jackson Heart Study, we examined the cross-sectional associations of cumulative psychosocial factors with CVD risk factors among 5306 African Americans. We utilized multivariable Poisson regression to estimate sex-stratified prevalence ratios (PR 95% confidence interval-CI) of obesity, hypertension and diabetes prevalence and hypertension and diabetes control with negative affect (cynicism, anger-in, anger-out, depressive symptoms and cumulative negative affect) and stress (global stress, weekly stress, major life events-MLEs and cumulative stress), adjusting for demographics, socioeconomic status, and behaviors. RESULTS: After full adjustment, high (vs. low) cumulative negative affect was associated with prevalent obesity among men (PR 1.36 95% CI 1.16-1.60), while high (vs. low) cumulative stress was similarly associated with obesity among men and women (PR 1.24 95% CI 1.01-1.52 and PR 1.13 95% CI 1.03-1.23, respectively). Psychosocial factors were more strongly associated with prevalent hypertension and diabetes among men than women. For example, men who reported high cynicism had a 12% increased prevalence of hypertension (PR 1.12, 95% CI 1.03-1.23). Psychosocial factors were more strongly associated with lower hypertension and diabetes control for women than men. Women who reported high (vs. low) cynicism had a 38% lower prevalence of hypertension control (PR 0.62, 95% CI 0.46-0.84). CONCLUSIONS: Cumulative psychosocial factors were associated with CVD risk factors and disease management among African Americans. The joint accumulation of psychosocial factors was more associated with risk factors for men than women.

Life Course Socioeconomic Status and Hypertension in African American Adults: The Jackson Heart Study.

BACKGROUND: Limited research has examined the association of life-course socioeconomic status (SES) with hypertension prevalence and incidence in a large cohort of African Americans. METHODS: Among 4,761 participants from the Jackson Heart Study (JHS), we examined the association of SES indicators with prevalent and incident hypertension. We used multivariable Poisson regression to estimate prevalence ratios (PR, 95% confidence interval-CI) of baseline (2000-2004) hypertension by adult (education, income, occupation, wealth) and childhood (mother's education) SES. Cox proportional hazards regression was used to estimate hazard ratios (HR, 95% CI) of incident hypertension by adult and childhood SES (2005-2013; 7.21 median years of follow-up). We also examined the association of childhood-to-adult SES mobility (parent-to-adult education) with prevalent and incident hypertension. Model 1 adjusted for age and sex. Model 2 added waist circumference, behaviors (smoking, alcohol, physical activity, diet), and diabetes prevalence. RESULTS: High (vs. low) adult SES measures were associated with a lower prevalence of hypertension, with the exception of having a college degree and upper-middle income (PR: 1.04, 95% CI: 1.01, 1.07; PR: 1.05, 95% CI: 1.01, 1.09, respectively). Higher childhood SES was associated with a lower prevalence and risk of hypertension (PR: 0.83, 95%: CI 0.75, 0.91; HR: 0.76, 95% CI: 0.65, 0.89, respectively). Upward mobility and consistent high SES (vs. consistent low SES) from childhood to adulthood was associated with a greater prevalence, but lower incidence of hypertension. CONCLUSION: Efforts to prevent hypertension among African Americans should consider childhood and current SES status.

The relationship between neighborhood socioeconomic deprivation and telomere length: The 1999-2002 National Health and Nutrition Examination Survey.

Socioeconomically disadvantaged neighborhoods have been associated with poor health outcomes. Little is known about the biological mechanism by which deprived neighborhood conditions exert negative influences on health. Data from the 1999-2002 National Health and Nutrition Examination Surveys (NHANES) were used to assess the relationship between neighborhood deprivation index (NDI) and log-transformed leukocyte telomere length (LTL) via multilevel modeling to control for census tract level clustering. Models were constructed using tertiles of NDI (ref = low NDI). NDI was calculated using census tract level socioeconomic indicators from the 2000 U.S. Census. The sample (n = 5,106 adults) was 49.8% female and consisted of 82.9% non-Hispanic whites, 9.4% non-Hispanic blacks, and 7.6% Mexican Americans. Mean age was 45.8 years. Residents of neighborhoods with high NDI were younger, non-white, had lower educational attainment, and had a lower poverty to income ratio (all p < 0.0001). Neighborhood deprivation was inversely associated with LTL among individuals living in neighborhoods with medium NDI (ß = -0.043, SE = 0.012, p = 0.0005) and high NDI (ß = -0.039, SE = 0.013, p = 0.003). Among men, both medium (ß = -0.042, SE = 0.015, p = 0.006) and high (ß = -0.047, SE = 0.015, p = 0.001) NDI were associated with shorter LTL. Among women, only medium NDI (ß = -0.020, SE = 0.016, p = 0.009) was associated with shorter LTL. After controlling for individual characteristics, including individual-level socioeconomic status, increasing neighborhood socioeconomic deprivation is associated with shorter LTL among a nationally representative sample of US adults. This suggests that telomere shortening may be a mechanism through which neighborhood deprivation results in poor health outcomes.

Associations of smoking indicators and cotinine levels with telomere length: National Health and Nutrition Examination Survey.

The influence of smoking exposure on telomere length with a focus on the impact of race has rarely been discussed. We performed a cross sectional analysis into the associations of smoking indicators with leukocyte telomere length (LTL) by race among 5864 nationally representative sample of US adults (≥20 years). Data from 1999 to 2002 National Health and Nutrition Examination Survey was used for the analysis. Smoking indicators were assessed by interviews and serum cotinine levels. LTL was quantified by polymerase chain reaction. Multiple linear regressions were used to assess the association with adjustment for covariates, sample weights and design effects separately for Whites, Blacks and Mexican Americans. The intensity of smoking, measured by the average number of cigarettes consumed per day, was negatively associated with LTL among Whites (ß: -3.87, 95% CI: -5.98 to -1.21) and among Blacks (ß: -15.46, 95% CI: -29.79 to -2.12) participants. Compared with cotinine level < 0.05 ng/ml, cotinine level ≥3 ng/ml was associated with shorter LTL (ß: -77.92, 95% CI = -143.05 to -11.70) among Whites, but not among Blacks. We found increased number of cigarette consumption to be associated with shorter LTL in both Blacks and Whites, indicating that the impact of smoking on life-shortening diseases could partly be explained by telomere biology. Increased cotinine concentration however, was associated with shorter LTL only among Whites, not among Blacks. This differential relationship that we observed may have implications in interpreting cotinine as an objective biomarker of smoking exposure across races and warrant additional prospective investigation.

Reducing Cardiovascular Disparities Through Community-Engaged Implementation Research: A National Heart, Lung, and Blood Institute Workshop Report.

Cardiovascular disparities remain pervasive in the United States. Unequal disease burden is evident among population groups based on sex, race, ethnicity, socioeconomic status, educational attainment, nativity, or geography. Despite the significant declines in cardiovascular disease mortality rates in all demographic groups during the last 50 years, large disparities remain by sex, race, ethnicity, and geography. Recent data from modeling studies, linked micromap plots, and small-area analyses also demonstrate prominent variation in cardiovascular disease mortality rates across states and counties, with an especially high disease burden in the southeastern United States and Appalachia. Despite these continued disparities, few large-scale intervention studies have been conducted in these high-burden populations to examine the feasibility of reducing or eliminating cardiovascular disparities. To address this challenge, on June 22 and 23, 2017, the National Heart, Lung, and Blood Institute convened experts from a broad range of biomedical, behavioral, environmental, implementation, and social science backgrounds to summarize the current state of knowledge of cardiovascular disease disparities and propose intervention strategies aligned with the National Heart, Lung, and Blood Institute mission. This report presents the themes, challenges, opportunities, available resources, and recommended actions discussed at the workshop.

The Epidemiology of Coping in African American Adults in the Jackson Heart Study (JHS).

Differences in coping within the African American population are not well understood, yet these differences may be critical to reducing stress, improving health, and reducing racial health disparities. Using a descriptive, exploratory analysis of the Jackson Heart Study (N = 5301), we examine correlations between coping responses and associations between coping and demographic, socioeconomic, psychosocial, and neighborhood factors. Overall, coping responses were not strongly correlated and patterns of associations between covariates and coping responses were largely inconsistent. The results suggest that coping varies substantially within this African American population and is driven mainly by psychosocial factors such as spirituality and interpersonal support. Understanding these complex relationships may inform strategies by which to intervene in the stress process to mitigate the effects of stress on health and to identify vulnerable subgroups of African Americans that might need targeted interventions to reduce exposure to stressors and improve coping capacities.

Differentially conserved transcriptomic response to adversity related to self-rated health in the multi-ethnic study of atherosclerosis.

Self-rated health (SRH) is considered a strong indicator of well-being and clinical health status and has been linked to inflammatory markers. The objective of this work was to examine how self-rated physical health (SRPH) and mental health (SRMH) influence the immune system through the regulation of a stress-related gene expression profile known as the 'conserved transcriptional response to adversity' (CTRA), which involves the up-regulation of pro-inflammatory genes and down-regulation of genes involved in type I interferon (IFN) response and antibody synthesis. CTRA expression data were derived from genome-wide transcriptional data on purified monocytes in 1264 adult participants from the multi-ethnic study of atherosclerosis. SRPH and SRMH were assessed through the SF-12 questionnaire. Multiple linear regression models were used to determine the association between the composite score of the CTRA subsets and SRPH and SRMH. Higher scores of SRPH and SRMH were associated with an increased expression of the overall CTRA profile. The individual gene subsets analysis did not reveal an increased expression of pro-inflammatory genes in persons with lower scores of SRH. However, we observed that higher scores of SRPH positively modulate the immune response through the up-regulation of both type I interferon response and antibody synthesis-related genes, while better scores of SRMH were associated with a down-regulation of genes involved in antibody synthesis. The significant association between SRH and a gene expression profile related to type I IFN response and antibody synthesis suggests that SRH may be linked to the immunocompetence status. Impact statement In this work, we evaluated for the first time how self-rated mental (SRMH) and physical health (SRPH) influence the immune response at the molecular level in a large multi-ethnic cohort. We observed that both SRMH and SRPH are related to immunocompetence status. These findings indicated that the link between how we perceive our health and poorer health outcomes could be explained by alterations in the immune response by shifting the expression of genes related to the type I IFN response and antibody synthesis.

Race-specific associations between health-related quality of life and cellular aging among adults in the United States: evidence from the National Health and Nutrition Examination Survey.

PURPOSE: Poor health-related quality of life (HRQOL) could lead to higher morbidity and mortality through telomere attrition or accelerated cellular aging. We conducted a cross-sectional analysis to examine the relationship between four dimensions of HRQOL and leukocyte telomere length (LTL) among a nationally representative sample of 3547 US adults (≥20 years) using the data from the 2001-2002 National Health and Nutrition Examination Survey. METHOD: We used HRQOL survey information collected on individuals' self-rated general health, recent physical health, recent mental health, and recent activity limitation. Telomere length was assessed using quantitative polymerase chain reaction. Multiple linear regressions were used to estimate the relationship between each dimension of HRQOL and log-transformed values of LTL with adjustment for sample weights and design effects. RESULTS: HRQOL-race interactions were significant, and the results were stratified by race. After controlling for demographic factors, disease conditions, and lifestyle variables, worse general health was significantly associated with shorter LTL for Blacks (coefficient, ß: -0.022, 95% Confidence Interval, 95% CI: -0.03 to -0.01), but not for Whites or Mexican Americans. Unwell physical health was associated with shorter telomere length for Whites (ß: -0.005, 95% CI: -0.01 to -0.001) only. Unwell mental health showed no significant association with LTL in any race. CONCLUSIONS: Although longitudinal studies are needed to prove causality, our findings suggest that HRQOL could be associated with LTL shortening. We also found a possible racial difference in this association and recommend additional multiethnic studies to confirm this and to understand the reasons and consequences of this difference.

Circadian CLOCK gene polymorphisms in relation to sleep patterns and obesity in African Americans: findings from the Jackson heart study.

BACKGROUND: Circadian rhythms regulate key biological processes and the dysregulation of the intrinsic clock mechanism affects sleep patterns and obesity onset. The CLOCK (circadian locomotor output cycles protein kaput) gene encodes a core transcription factor of the molecular circadian clock influencing diverse metabolic pathways, including glucose and lipid homeostasis. The primary objective of this study was to evaluate the associations between CLOCK single nucleotide polymorphisms (SNPs) and body mass index (BMI). We also evaluated the association of SNPs with BMI related factors such as sleep duration and quality, adiponectin and leptin, in 2962 participants (1116 men and 1810 women) from the Jackson Heart Study. Genotype data for the selected 23 CLOCK gene SNPS was obtained by imputation with IMPUTE2 software and reference phase data from the 1000 genome project. Genetic analyses were conducted with PLINK RESULTS: We found a significant association between the CLOCK SNP rs2070062 and sleep duration, participants carriers of the T allele showed significantly shorter sleep duration compared to non-carriers after the adjustment for individual proportions of European ancestry (PEA), socio economic status (SES), body mass index (BMI), alcohol consumption and smoking status that reach the significance threshold after multiple testing correction. In addition, we found nominal associations of the CLOCK SNP rs6853192 with longer sleep duration and the rs6820823, rs3792603 and rs11726609 with BMI. However, these associations did not reach the significance threshold after correction for multiple testing. CONCLUSIONS: In this work, CLOCK gene variants were associated with sleep duration and BMI suggesting that the effects of these polymorphisms on circadian rhythmicity may affect sleep duration and body weight regulation in Africans Americans.

Less Than Ideal Cardiovascular Health Is Associated With Shorter Leukocyte Telomere Length: The National Health and Nutrition Examination Surveys, 1999-2002.

BACKGROUND: The associations between individual cardiovascular disease risk factors and leukocyte telomere length (LTL) have been inconclusive. We investigated the association between LTL and overall cardiovascular health (CVH) as defined by the American Heart Association and whether the association is modified by sex and race/ethnicity. METHODS AND RESULTS: We included 5194 adults (aged ≥20) from the National Health and Nutrition Examination Survey 1999-2002. CVH was defined as a composite score of the 7 metrics (smoking, physical activity, diet, body mass index, blood pressure, total cholesterol, and fasting blood glucose) and categorized as "poor," "intermediate," and "ideal." LTL was assayed from whole blood using the quantitative polymerase chain reaction method relative to standard reference DNA. Multivariable linear regression models were used to estimate the association between CVH and log-transformed LTL. We found strong graded association between CVH and LTL in the overall sample, with evidence of dose-response relationship (P for trend=0.013). Individuals with poor and intermediate CVH had significantly shorter LTL than individuals with ideal CVH (-3.4% [95% CI=-6.0%, -0.8%] and -2.4% [-4.4%, -0.3%], respectively), after adjustment for demographic variables, socioeconomic status, and C-reactive protein. The association was stronger in women (-6.6% [-10.2%, -2.9%] for poor vs ideal CVH) and non-Hispanic whites (-4.3% [-7.1%, -1.4%] for poor vs ideal CVH). CONCLUSIONS: The findings suggest that less-than-ideal CVH is associated with shorter LTL, but this association varies by sex and race/ethnicity. Future longitudinal research is needed to elucidate the mechanisms that underlie the association between CVH and LTL.

Obstructive sleep apnea risk and leukocyte telomere length in African Americans from the MH-GRID study.

PURPOSE: Shorter telomere length and obstructive sleep apnea are associated with increased oxidative stress and chronic inflammation, which are both considered leading causes of age-related diseases. Different forms of sleep disordered breathing have been linked to telomere length although their relationship remains uncertain. The purpose of this study was to explore the associations between the risk of obstructive sleep apnea and telomere length in African Americans. METHODS: The analysis included 184 women and 122 men aged 30-55 years from the Morehouse School of Medicine Study. Relative TL (T/S ratio) was measured from peripheral blood leukocytes using quantitative real-time polymerase chain reaction. The Berlin questionnaire was used for OSA risk assessments. Multivariable linear regression models were used to examine the associations between OSA risk and LTL. RESULTS: We observed that LTL varied by OSA risk in women (0.532 ± 0.006 vs. 0.569 ± 0.008) (p = 0.04). Multiple linear regression analysis confirmed that women at higher risk for OSA presented shorter LTL compared to those at lower risk, independent of age, income, education, obesity, smoking, alcohol consumption, and hypertension. These differences were not observed in men. CONCLUSIONS: Our findings suggest that OSA risk may contribute to the acceleration of cellular aging processes through telomere shortening.

Neighborhood social and physical environments and type 2 diabetes mellitus in African Americans: The Jackson Heart Study.

Using data from Jackson Heart Study, we investigated the associations of neighborhood social and physical environments with prevalence and incidence of type 2 diabetes mellitus (T2DM) in African Americans (AA). Among non-diabetic participants at baseline (n=3670), 521 (14.2%) developed T2DM during a median follow-up of 7.3 years. Measures of neighborhood social environments, and food and physical activity resources were derived using survey-and GIS-based methods. Prevalence ratios (PR) and Hazard ratios (HR) were estimated using generalized estimating equations and Cox proportional hazards models. Higher neighborhood social cohesion was associated with a 22% lower incidence of T2DM while higher density of unfavorable food stores was associated with a 34% higher incidence of T2DM after adjusting for individual-level risk factors (HR=0.78 [95% CI:0.62, 0.99] and HR=1.34 [1.12, 1.60], respectively). In addition, neighborhood problems was also associated with prevalence of T2DM (PR=1.12 [1.03, 1.21]) independent of individual-level risk factors. Our findings suggest that efforts to strengthen community ties or to attract healthy food retail outlets might be important strategies to consider for prevention of T2DM in AA.

Associations between Vitamin D and Cardiovascular Disease Risk Factors in African Americans Are Partly Explained by Circulating Adipokines and C-Reactive Protein: The Jackson Heart Study.

BACKGROUND: Although it is recognized that vitamin D deficiency is associated with cardiovascular disease (CVD) risk factors, and is more common in African Americans (AAs), the pathologic mechanisms by which vitamin D may influence these risk factors are poorly understood. OBJECTIVES: We explored the association between vitamin D status, as reflected by serum 25-hydroxyvitamin D [25(OH)D] concentrations, and CVD risk factors including mean arterial pressure (MAP), fasting plasma glucose (FPG), plasma HDL cholesterol, and waist circumference (WC) in adult AAs. We also tested whether plasma C-reactive protein (CRP), adipokines (adiponectin and leptin), and aldosterone mediated the associations between 25(OH)D and these risk factors. METHODS: Data on 4010 (63.8% women; mean age: 54.0 y) individuals from the Jackson Heart Study were analyzed. Multivariable linear regression models were used to examine the associations of 25(OH)D with CVD risk factors. We used path analysis and bootstrapping methods to quantify and test the share of these associations that was statistically explained by each of the mediators by decomposing the associations into direct and indirect effects. RESULTS: Serum 25(OH)D concentrations were inversely associated with WC, FPG, and MAP and were positively associated with HDL cholesterol in multivariable analysis. A nearly 20% effect of 25(OH)D on MAP was masked by aldosterone (total indirect effect: ß = 0.01, P < 0.05). Approximately 23% of the effect of 25(OH)D on WC (ß = -0.03, P < 0.05) and ∼9% of the effect of 25(OH)D on FPG (ß = -0.02, P < 0.05) were mediated through CRP, adiponectin, and leptin together. A 23% share of the association between 25(OH)D and HDL cholesterol was mediated by adiponectin alone (ß = 0.03, P < 0.05). CONCLUSIONS: Our findings suggest that the associations between vitamin D status and CVD risk factors in AAs are partially mediated through circulating adipokines and CRP. More evidence, however, is required from longitudinal and randomized controlled studies to validate our findings.

Vitamin D Receptor Gene Polymorphisms Are Associated with Abdominal Visceral Adipose Tissue Volume and Serum Adipokine Concentrations but Not with Body Mass Index or Waist Circumference in African Americans: The Jackson Heart Study.

BACKGROUND: The biological actions of vitamin D are mediated through the vitamin D receptor (VDR). Single-nucleotide polymorphisms (SNPs) in the VDR gene have been previously associated with adiposity traits. However, to our knowledge, few studies have included direct measures of adiposity and adipokine concentrations. OBJECTIVE: We examined the association of tagging SNPs in the VDR gene with multiple adiposity measures, including waist circumference (WC), body mass index (BMI), body fat percentage, subcutaneous and visceral adipose tissue (VAT) volume, and serum adipokine (adiponectin and leptin) concentrations in adult African Americans (AAs). METHODS: Data from 3020 participants (61.9% women; mean age, 54.6 y) from the Jackson Heart Study were used for this analysis. Forty-five tag SNPs were chosen with the use of genotype data from the International HapMap project. We used linear regression to test the associations of imputed VDR SNPs with each of the traits, adjusted for age, sex, educational status, physical activity, smoking, alcohol intake, serum vitamin D concentration, European ancestry, and multiple testing. RESULTS: The G allele of the SNP rs4328262 remained associated with increased VAT volume after multiple testing correction (ß = 45.7; P < 0.001). The A allele of another SNP (rs11574070) was nominally associated with body fat percentage (ß = 0.96; P = 0.002). None of the VDR SNPs analyzed showed any link with WC or BMI. The A allele of rs2228570 (ß = 0.08; P = 0.001) for men and the T allele of rs2853563 (ß = 0.04; P < 0.001) for women remained positively associated with serum adiponectin concentrations after multiple testing correction. CONCLUSION: Although we did not find any association for anthropometric measures, we did observe associations of VDR variants with serum adipokines and with the more metabolically active fat, VAT. Therefore, our findings demonstrate a possible role of VDR variants in regulating adipose tissue activity and adiposity among AAs.

Association of adiponectin and socioeconomic status in African American men and women: the Jackson heart study.

BACKGROUND: Recent emphasis has been placed on elucidating the biologic mechanism linking socioeconomic status (SES) to cardiovascular disease (CVD). Positive associations of inflammatory biomarkers provide evidence suggestive of a biologic pathway by which SES may predispose to CVD. African Americans have disproportionately lower SES and have a higher prevalence of CVD risk factors compared to most ethnic/racial groups. Adiponectin (an anti-inflammatory marker) is also lower. The objective of this study was to assess the association of adiponectin with SES among African American men and women using the Jackson Heart Study. METHODS: Study sample included 4340 participants. Linear regression was performed separately by SES and stratified by sex. Annual household income and level of education was used as proxies for SES. Crude, age, health behavior and health status adjusted models were analyzed. The main outcome was log-transformed adiponectin. RESULTS: Men in the lowest income group had significantly higher adiponectin than those in the highest income group in the fully adjusted model (ß/standard error [se], p value = .16/.08, p = .0008. Men with < high school level of education had significantly higher adiponectin in the crude and age adjusted models than those with ≥ college degree (.25/.05, p < .0001; .14/.05/ p = .005, respectively). Women with some college or vocational training in the crude and age adjusted models had lower adiponectin compared to women with ≥ college degree (-.09/.03, p = .004; -.06/.03, p = .04, respectively). CONCLUSION: Findings suggest a potential inverse biologic pathway between annual household income and adiponectin among African American men. There was no such finding among women. Findings suggest interventions should be targeted for higher SES African American men to improve adiponectin levels.

Perceived neighborhood problems are associated with shorter telomere length in African American women.

OBJECTIVES: African Americans (AA) experience higher levels of stress related to living in racially segregated and poor neighborhoods. However, little is known about the associations between perceived neighborhood environments and cellular aging among adult AA. This study examined whether perceived neighborhood environments were associated with telomere length (TL) in AA after adjustment for individual-level risk factors. METHODS: The analysis included 158 women and 75 men AA aged 30-55 years from the Morehouse School of Medicine Study. Relative TL (T/S ratio) was measured from peripheral blood leukocytes using quantitative real-time polymerase chain reaction. Multivariable linear regression models were used to examine the associations of perceived neighborhood social cohesion, problems, and overall unfavorable perceptions with log-TL. RESULTS: Women had significantly longer TL than men (0.59 vs. 0.54, p=0.012). After controlling for sociodemographic, and biomedical and psychosocial factors, a 1-SD increase in perceived neighborhood problems was associated with 7.3% shorter TL in women (Mean Difference [MD]=-0.073 (Standard Error=0.03), p=0.012). Overall unfavorable perception of neighborhood was also associated with 5.9% shorter TL among women (MD=-0.059(0.03), p=0.023). Better perceived social cohesion were associated with 2.4% longer TL, but did not reach statistical significance (MD=0.024(0.02), p=0.218). No association was observed between perceived neighborhood environments and TL in men. CONCLUSIONS: Our findings suggest that perceived neighborhood environments may be predictive of cellular aging in AA women even after accounting for individual-level risk factors. Additional research with a larger sample is needed to determine whether perceived neighborhood environments are causally related to TL.

Perceived discrimination is associated with health behaviours among African-Americans in the Jackson Heart Study.

BACKGROUND: Using Jackson Heart Study data, we examined associations of multiple measures of perceived discrimination with health behaviours among African-Americans (AA). METHODS: The cross-sectional associations of everyday, lifetime and burden of discrimination with odds of smoking and mean differences in physical activity, dietary fat and sleep were examined among 4925 participants aged 35-84 years after adjustment for age and socioeconomic status (SES). RESULTS: Men reported slightly higher levels of everyday and lifetime discrimination than women and similar levels of burden of discrimination as women. After adjustment for age and SES, everyday discrimination was associated with more smoking and a greater percentage of dietary fat in men and women (OR for smoking: 1.13, 95% CI 1.00 to 1.28 and 1.19, 95% CI 1.05 to 1.34; mean difference in dietary fat: 0.37, p<0.05 and 0.43, p<0.01, in men and women, respectively). Everyday and lifetime discrimination were associated with fewer hours of sleep in men and women (mean difference for everyday discrimination: -0.08, p<0.05 and -0.18, p<0.001, respectively; and mean difference for lifetime discrimination: -0.08, p<0.05 and -0.24, p<0.001, respectively). Burden of discrimination was associated with more smoking and fewer hours of sleep in women only. CONCLUSIONS: Higher levels of perceived discrimination were associated with select health behaviours among men and women. Health behaviours offer a potential mechanism through which perceived discrimination affects health in AA.

Association of ADIPOQ gene with type 2 diabetes and related phenotypes in African American men and women: the Jackson Heart Study.

BACKGROUND: African Americans experience disproportionately higher prevalence of type 2 diabetes and related risk factors. Little research has been done on the association of ADIPOQ gene on type 2 diabetes, plasma adiponectin, blood glucose, HOMA-IR and body mass index (BMI) in African Americans. The objective of our research was to assess such associations with selected SNPs. The study included a sample of 3,020 men and women from the Jackson Heart Study who had ADIPOQ genotyping information. Unadjusted and adjusted regression models with covariates were used with type 2 diabetes and related phenotypes as the outcome stratified by sex. RESULTS: There was no association between selected ADIPOQ SNPs with type 2 diabetes, blood glucose, or BMI in men or women. There was a significant association between variant rs16861205 and lower adiponectin in women with minor allele A in the fully adjusted model (ß(SE) p = -.13(0.05), 0.003). There was also a significant association with variant rs7627128 and lower HOMA-IR among men with minor allele A in the fully adjusted model (ß(SE) p = -0.74(0.20), 0.0002). CONCLUSIONS: These findings represent new insights regarding the association of ADIPOQ gene and type 2 diabetes and related phenotypes in African American men and women.

Prevalence, associated factors and heritabilities of metabolic syndrome and its individual components in African Americans: the Jackson Heart Study.

OBJECTIVE: Both environmental and genetic factors play important roles in the development of metabolic syndrome (MetS). Studies about its associated factors and genetic contribution in African Americans (AA) are sparse. Our aim was to report the prevalence, associated factors and heritability estimates of MetS and its components in AA men and women. PARTICIPANTS AND SETTING: Data of this cross-sectional study come from a large community-based Jackson Heart Study (JHS). We analysed a total of 5227 participants, of whom 1636 from 281 families were part of a family study subset of JHS. METHODS: Participants were classified as having MetS according to the Adult Treatment Panel III criteria. Multiple logistic regression analysis was performed to isolate independently associated factors of MetS (n=5227). Heritability was estimated from the family study subset using variance component methods (n=1636). RESULTS: About 27% of men and 40% of women had MetS. For men, associated factors with having MetS were older age, lower physical activity, higher body mass index, and higher homocysteine and adiponectin levels (p<0.05 for all). For women, in addition to all these, lower education, current smoking and higher stress were also significant (p<0.05 for all). After adjusting for covariates, the heritability of MetS was 32% (p<0.001). Heritability ranged from 14 to 45% among its individual components. Relatively higher heritability was estimated for waist circumference (45%), high density lipoprotein-cholesterol (43%) and triglycerides (42%). Heritability of systolic blood pressure (BP), diastolic BP and fasting blood glucose was 16%, 15% and 14%, respectively. CONCLUSIONS: Stress and low education were associated with having MetS in AA women, but not in men. Higher heritability estimates for lipids and waist circumference support the hypothesis of lipid metabolism playing a central role in the development of MetS and encourage additional efforts to identify the underlying susceptibility genes for this syndrome in AA.