Associations of body mass index with incident hypertension in American white, American black and Chinese Asian adults in early and middle adulthood: the Coronary Artery Risk Development in Young Adults (CARDIA) study, the Atherosclerosis Risk in Communities (ARIC) study and the People's Republic of China (PRC) study

The association of body mass index (BMI) with blood pressure may be stronger in Asian than non-Asian populations, however, longitudinal studies with direct comparisons between ethnicities are lacking. We compared the relationship of BMI with incident hypertension over approximately 9.5 years of follow-up in young (24-39 years) and middle-aged (45-64 years) Chinese Asians (n=5354), American Blacks (n=6076) and American Whites (n=13451). We estimated risk differences using logistic regression models and calculated adjusted incidences and incidence differences. To facilitate comparisons across ethnicities, standardized estimates were calculated using mean covariate values for age, sex, smoking, education and field center, and included the quadratic terms for BMI and age. Weighted least-squares regression models with were constructed to summarize ethnic-specific incidence differences across BMI. Wald statistics and p-values were calculated based on chi-square distributions. The association of BMI with the incidence difference for hypertension was steeper in Chinese (p<0.05) than in American populations during young and middle-adulthood. For example, at a BMI of 25 vs 21 kg/m2 the adjusted incidence differences per 1000 persons (95% CI) in young adults with a BMI of 25 vs those with a BMI of 21 was 83 (36- 130) for Chinese, 50 (26-74) for Blacks and 30 (12-48) for Whites; among middle-aged adults it was 137 (77-198) for Chinese, 49 (9-88) for Blacks and 54 (38-69) for Whites. Whether hypertension carries the same level of risk of stroke or cardiovascular disease across national or ethnic groups remains uncertain.

Prevalence of cardiovascular risk factors among racial and ethnic minorities with schizophrenia spectrum and bipolar disorders: a critical literature review

OBJECTIVE

People with serious mental illness (SMI) die at least 11 years earlier than the general U.S. population, on average, due largely to cardiovascular disease (CVD). Disparities in CVD morbidity and mortality also occur among some U.S. racial and ethnic minorities. The combined effect of race/ethnicity and SMI on CVD-related risk factors, however, remains unclear. To address this gap, we conducted a critical literature review of studies assessing the prevalence of CVD risk factors (overweight/obesity, diabetes mellitus, metabolic syndrome, hypercholesterolemia, hypertension, cigarette smoking, and physical inactivity) among U.S. racial/ethnic groups with schizophrenia-spectrum and bipolar disorders.

METHODS AND RESULTS

We searched MEDLINE and PsycINFO for articles published between 1986 and 2013. The search ultimately yielded 40 articles. There was great variation in sampling, methodology, and study populations. Results were mixed, though there was some evidence for increased risk for obesity and diabetes mellitus among African Americans, and to a lesser degree for Hispanics, compared to non-Hispanic Whites. Sex emerged as an important possible effect modifier of risk, as women had higher CVD risk among all racial/ethnic subgroups where stratified analyses were reported.

CONCLUSIONS

Compared to general population estimates, there was some evidence for an additive risk for CVD risk factors among racial/ethnic minorities with SMI. Future studies should include longitudinal assessment, stratification by sex, subgroup analyses to clarify the mechanisms leading to potentially elevated risk, and the evaluation of culturally appropriate interventions to eliminate the extra burden of disease in this population.

Epigenetic markers of renal function in african americans

Chronic kidney disease (CKD) is an increasing concern in the United States due to its rapidly rising prevalence, particularly among African Americans. Epigenetic DNA methylation markers are becoming important biomarkers of chronic diseases such as CKD. To better understand how these methylation markers play a role in kidney function, we measured 26,428 DNA methylation sites in 972 African Americans from the Genetic Epidemiology Network of Arteriopathy (GENOA) study. We then evaluated (1) whether epigenetic markers are associated with estimated glomerular filtration rate (eGFR), (2) whether the significantly associated markers are also associated with traditional risk factors and/or novel biomarkers for eGFR, and (3) how much additional variation in eGFR is explained by epigenetic markers beyond established risk factors and biomarkers. The majority of methylation markers most significantly associated with eGFR (24 out of the top 30) appeared to function, at least in part, through pathways related to aging, inflammation, or cholesterol. However, six epigenetic markers were still able to significantly predict eGFR after adjustment for other risk factors. This work shows that epigenetic markers may offer valuable new insight into the complex pathophysiology of CKD in African Americans.

A Framework to Examine the Role of Epigenetics in Health Disparities among Native Americans

Background. Native Americans disproportionately experience adverse childhood experiences (ACEs) as well as health disparities, including high rates of posttraumatic stress, depression, and substance abuse. Many ACEs have been linked to methylation changes in genes that regulate the stress response, suggesting that these molecular changes may underlie the risk for psychiatric disorders related to ACEs. Methods. We reviewed published studies to provide evidence that ACE-related methylation changes contribute to health disparities in Native Americans. This framework may be adapted to understand how ACEs may result in health disparities in other racial/ethnic groups. Findings. Here we provide evidence that links ACEs to methylation differences in genes that regulate the stress response. Psychiatric disorders are also associated with methylation differences in endocrine, immune, and neurotransmitter genes that serve to regulate the stress response and are linked to psychiatric symptoms and medical morbidity. We provide evidence linking ACEs to these epigenetic modifications, suggesting that ACEs contribute to the vulnerability for developing psychiatric disorders in Native Americans. Conclusion. Additional studies are needed to better understand how ACEs contribute to health and well-being. These studies may inform future interventions to address these serious risks and promote the health and well-being of Native Americans.

The epigenome and nature/nurture reunification: a challenge for anthropology

Recognition among molecular biologists of variables external to the body that can bring about hereditable changes in gene expression or cellular phenotypes has reignited nature/nurture discussion. These epigenetic findings may well set off a new round of somatic reductionism because research is confined largely to the molecular level. A brief review of the late nineteenth-century formulation of the nature/nurture concept is followed by a discussion of the positions taken by Boas and Kroeber on this matter. I then illustrate how current research into Alzheimer's disease uses a reductionistic approach, despite epigenetic findings in this field that make the shortcomings of reductionism clear. In order to transcend the somatic reductionism associated with epigenetics, drawing on concepts of local biologies and embedded bodies, anthropologists can carry out research in which epigenetic findings are contextualized in the specific historical, socio/political, and environmental realities of lived experience.

Social epidemiology of diabetes and associated conditions

Research focusing on the social determinants of diabetes has focused on individual-level factors such as health behaviors, socioeconomic status, and depression. Fewer studies that incorporate a broader consideration of the multiple contexts or organizational levels (eg, family, health care setting, neighborhood) within which individuals are embedded exist in the mainstream diabetes literature. Such an approach would enhance our understanding of this complex disease, and thus, future avenues of research should consider the following: (1) a life-course approach, which examines the influence of early life exposures on the development of diabetes; (2) aiming to understand the biological mechanisms of social determinants of diabetes; and (3) implementing interventions on multiple levels. Integrating this multilevel and life-course approach will require transdisciplinary science that brings together highly specialized expertise from multiple disciplines. Broadening the study of social determinants is a necessary step toward improving the prevention and treatment of type 2 diabetes.

Mapping the new molecular landscape: social dimensions of epigenetics

Epigenetics is the study of changes in gene expression caused by mechanisms other than changes in the DNA itself. The field is rapidly growing and being widely promoted, attracting attention in diverse arenas. These include those of the social sciences, where some researchers have been encouraged by the resonance between imaginaries of development within epigenetics and social theory. Yet, sustained attention from science and technology studies (STS) scholars to epigenetics and the praxis it propels has been lacking. In this article, we reflexively consider some of the ways in which epigenetics is being constructed as an area of biomedical novelty and discuss the content and logics underlying the ambivalent promises being made by scientists working in this area. We then reflect on the scope, limits and future of engagements between epigenetics and the social sciences. Our discussion is situated within wider literatures on biomedicine and society, the politics of "interventionist STS," and on the problems of "caseness" within empirical social science.

The hidden cost of moving up: type 2 diabetes and the escape from persistent poverty in the American South

OBJECTIVES

The paper tests the thrifty phenotype hypothesis, according to which nonharmonious growth trajectories are costly for adult health.

METHODS

The American surge in the prevalence of type 2 diabetes is concentrated in the South, a region characterized by a long history of poverty followed by rapid economic growth beginning in the 1960s. Civil rights legislation further accelerated income growth for African-Americans in the region. The paper investigates the hypothesis by using per capita income at the state level as a proxy for net nutritional conditions.

RESULTS

Regressions at the state level explain 56% of the variation in the prevalence rate of type 2 diabetes in 2009 using two explanatory variables: the ratio of per capita income in 1980 to that in 1950 and the share of the population that was African-American. The paper discusses ways that rapid economic growth may have translated into weight gain and type 2 diabetes.

CONCLUSIONS

If the thrifty phenotype hypothesis is correct, future rates in the prevalence of type 2 diabetes are predictable based on income history. The forecast for rapidly developing countries such as India and China are ominous.

The Nature/Culture of Genetic Facts

This review aims to explore the relationship between anthropology and genetics, an intellectual zone that has been occupied in different ways over the past century. One way to think about it is to contrast a classical “anthropological genetics” ( Roberts 1965 ), that is to say, a genetics that presumably informs anthropological issues or questions, with a “genomic anthropology” ( Pálsson 2008 ), that is to say, an anthropology that complements and relativizes modern genomics (on the model of, say, medical anthropology and legal anthropology). 1 This review argues that a principal contribution of anthropology to the study of human heredity lies in the ontology of genetic facts. For anthropology, genetic facts are not natural, with meanings inscribed on them, but are instead natural/cultural: The natural facts have cultural information (values, ideologies, meanings) integrated into them, not layered on them. To understand genetic facts involves confronting their production, which has classically been restricted to questions of methodology but which may be conceptualized more broadly. This review is not intended as a critique of the field of anthropological genetics, but as a reformulation of its central objects of study. I argue for reconceptualizing the ontology of scientific facts in anthropological genetics, not as (value-neutral) biological facts situated in a cultural context, but instead as inherently biocultural facts.

The disease burden across different ethnic groups in Amsterdam, the Netherlands, 2011-2030

BACKGROUND

Current disease burden estimates do not provide evidence across different ethnic groups. This study aims to assess the disease burden as measured by the disability-adjusted life years (DALYs) for six ethnic groups in Amsterdam, the Netherlands, for 2011 and 2030.

METHODS

The DALYs were calculated by combining three components: disease-/sex-/age-specific DALYs per person; disease-specific relative risks (RRs) by ethnicity; and sex-/age-specific population sizes by ethnicity in Amsterdam in 2011 and 2030. Disease-specific DALYs were derived from the National Institute of Public Health. The RRs were obtained through a systematic review of studies published in 1997-2008. The population figures were gathered from the Statistics Netherlands and municipality of Amsterdam.

RESULTS

The findings suggest that cardiovascular diseases and anxiety and depressive disorders dominate disease burden in all ethnic groups in 2011 and 2030. In most of the non-Western ethnic minorities, diabetes mellitus is the strongest contributor to the disease burden. The total disease burden will increase more strongly in non-Western ethnic minorities than ethnic Dutch. The 2030 disease burden is estimated to be highest among Surinamese and Antilleans.

CONCLUSIONS

In ethnic minorities, diabetes plays an important role in the disease burden, and the total disease burden will grow stronger than ethnic Dutch, resulting in a higher total disease burden for some ethnic groups in 2030. We encourage researchers to estimate the disease burden by ethnicity so that health priorities can be set in the fields of policy, health care and research.

Deep integration: letting the epigenome out of the bottle without losing sight of the structural origins of population health

Advances in stress physiology and molecular dynamics can illuminate population health inequality. The "weathering" hypothesis posits that socially structured, repeated stress process activation can accumulate and increase disease vulnerability across the life course in marginalized groups. The developmental origins of health and disease (DOHaD) hypothesis focuses on youthful programming for later life disease via epigenetic modifications to limiting uterine or early environments. Weathering and DOHaD are overlapping biopsychosocial models; yet, their emphases and implications vary. Evidence for the primacy of early development over experiences in young through middle adulthood for explaining population health inequality is lacking. By considering weathering and DOHaD together, we call for biomedical researchers to be more cautious in their claims about the social world and for a broader range of social researchers--including qualitative ones--to collaborate with them.

Beyond the Paleolithic prescription: incorporating diversity and flexibility in the study of human diet evolution

Evolutionary paradigms of human health and nutrition center on the evolutionary discordance or "mismatch" model in which human bodies, reflecting adaptations established in the Paleolithic era, are ill-suited to modern industrialized diets, resulting in rapidly increasing rates of chronic metabolic disease. Though this model remains useful, its utility in explaining the evolution of human dietary tendencies is limited. The assumption that human diets are mismatched to the evolved biology of humans implies that the human diet is instinctual or genetically determined and rooted in the Paleolithic era. This review looks at current research indicating that human eating habits are learned primarily through behavioral, social, and physiological mechanisms that start in utero and extend throughout the life course. Adaptations that appear to be strongly genetic likely reflect Neolithic, rather than Paleolithic, adaptations and are significantly influenced by human niche-constructing behavior. Several examples are used to conclude that incorporating a broader understanding of both the evolved mechanisms by which humans learn and imprint eating habits and the reciprocal effects of those habits on physiology would provide useful tools for structuring more lasting nutrition interventions.

Transgenerational Consequences of Racial Discrimination for African American Health

Disparities in African American health remain pervasive and persist transgenerationally. There is a growing consensus that both structural and interpersonal racial discrimination are key mechanisms affecting African American health. The Biopsychosocial Model of Racism as a Stressor posits that the persistent stress of experiencing discrimination take a physical toll on the health of African Americans and is ultimately manifested in the onset of illness. However, the degree to which the health consequences of racism and discrimination can be passed down from one generation to the next is an important avenue of exploration. In this review, we discuss and link literature across disciplines demonstrating the harmful impact of racism on African American physical health and the health of their offspring.

Race differences in age-trends of autonomic nervous system functioning

OBJECTIVE

The objective of this study was to consider race differences in age-trends of autonomic nervous system functioning, using a national data set with a broad age range.

METHODS

Measures of baseline heart rate variability (HRV) and HRV reactivity were derived from electrocardiograph (ECG) recordings taken at rest and during cognitive stress tasks. Age-trends in HRV and HRV reactivity were compared among 204 African Americans and 833 Whites ages 34 to 83 years (M = 53.7, SD = 11.4), before and after controlling for socioeconomic status (SES).

RESULTS

For HRV-reactivity, age-trends were steeper among African Americans and lower SES participants than Whites and higher SES participants. For baseline HRV, age-trends varied by SES but not race.

DISCUSSION

Results relating to HRV-reactivity (but not baseline HRV) were consistent with hypotheses suggesting that African Americans are exposed to higher levels of stress and experience accelerated declines in health across the life span. The relevance of the findings to research on social stress and health disparities is discussed.

Phenotype-environment mismatch due to epigenetic inheritance? Programming the offspring's epigenome and the consequences of migration

OBJECTIVE

It has been suggested that epigenetic inheritance is an important factor influencing mortality. We use data about the historical population of Québec (years 1670-1740) to study whether parents modify their offspring's phenotype epigenetically prior to conception in response to predicted/perceived mortality. If so, children growing up in the predicted environment enjoy a phenotype-environment-match that should lower mortality, whereas children growing up in a nonpredicted environment should have a higher mortality.

METHODS

We use the large urban-rural mortality differential to capture the predicted/perceived mortality environment. We categorize children into different groups by their migration status: conceived and living in the same environment (urban or rural); conceived in one but born in another environment (urban-to-rural or rural-to-urban); and born in one but migrating to another environment. We use Kaplan-Meier survival curves and fixed effect survival models to estimate to what extent child survival up to the age of 15 depends on migration status.

RESULTS

Child mortality within families that moved from urban to rural areas does not depend on the child's migration status. Within families that moved to urban areas, children who were conceived and born in the rural areas exhibit the lowest mortality. This contradicts a phenotype-environment-mismatch scenario, which would result in higher rather than lower mortality.

CONCLUSION

We do not find evidence for functional (adaptive) epigenetic inheritance. Migration into an environment with lower or higher extrinsic mortality affects child mortality within the families differently than predicted by the concept of epigenetic inheritance. The results suggest that epigenetic inheritance may not be important for child mortality among migrants.

Analysis of the prevalence of cardiovascular disease and associated risk factors for European-American and African-American populations in the state of Pennsylvania 2005-2009

We examined the burden of cardiovascular disease (CVD) and its associated risk factors using statewide representative data from the Pennsylvania Behavior Risk Factors Surveillance System. The data from 35,576 subjects aged ≥ 18 years participating in the Pennsylvania Behavior Risk Factors Surveillance System in 2005, 2007, and 2009 were analyzed. The age-adjusted prevalence rates of CVD were computed. Logistic regression analysis was applied to examine associations between the risk factors and CVD prevalence, with adjustment for confounding variables. The results showed that no significant changes in the prevalence of CVD, coronary heart disease, and stroke were observed in either European Americans or African Americans from 2005 to 2009 (p >0.05). African Americans had significantly greater CVD rates than European Americans. Although smoking rates significantly decreased, several other CVD risk factors (i.e., obesity, hypertension, and hypercholesterolemia) significantly increased from 2005 to 2009 in European Americans. Similar changes were observed in African Americans, although these changes did not reach statistical significance. Logistic regression analysis indicated that African Americans had a 35% greater risk of CVD. Education level less than high school, smoking, obesity, hypertension, and diabetes were significantly and positively associated with CVD. In conclusion, no significant achievements in CVD control and risk factor reduction were observed from 2005 to 2009 in Pennsylvania. Additional aggressive control of hypertension, obesity, and diabetes for both European and African Americans must be made to reduce the burden of CVD.

Mental health of African Americans and Caribbean blacks in the United States: results from the National Epidemiological Survey on Alcohol and Related Conditions

OBJECTIVES

Previous epidemiological studies have found lower mood, anxiety, and substance use disorder prevalence in Black Americans, in general, compared with White Americans. We estimated the prevalence and persistence of psychiatric disorders in African Americans, Caribbean Blacks, and non-Hispanic Whites.

METHODS

We drew data from wave 1 (2001-2002) of the National Epidemiological Survey of Alcohol and Related Conditions, a nationally representative sample of US adults, which included 7529 African Americans, 469 Caribbean Blacks, and 24 502 non-Hispanic Whites.

RESULTS

Blacks had equal or lower prevalence than Whites of lifetime (adjusted odds ratio [AOR] =0.6 for African Americans; 0.3 for Caribbean Blacks) and 12-month (AOR =0.7 for African Americans; 0.4 for Caribbean Blacks) Axis I psychiatric disorders, but higher prevalence of several personality disorders. Among Blacks, Caribbean Blacks had higher prevalence of 12-month psychotic disorders and lower lifetime prevalence of major depressive disorder, alcohol dependence, and drug abuse than African Americans. There were no differences in persistence of disorders between Caribbean Blacks and African Americans.

CONCLUSIONS

This study yielded new data on prevalence of mental disorders in these groups, which has important implications for clinical work with US Blacks.

Risk of cardiovascular disease in a traditional African population with a high infectious load: a population-based study

BACKGROUND

To test the inflammatory origin of cardiovascular disease, as opposed to its origin in western lifestyle. Population-based assessment of the prevalences of cardiovascular risk factors and cardiovascular disease in an inflammation-prone African population, including electrocardiography and ankle-arm index measurement. Comparison with known prevalences in American and European societies.

METHODOLOGY/PRINCIPAL FINDINGS

Traditional population in rural Ghana, characterised by adverse environmental conditions and a high infectious load. Population-based sample of 924 individuals aged 50 years and older. Median values for cardiovascular risk factors, including waist circumference, BMI, blood pressure, and markers of glucose and lipid metabolism and inflammation. Prevalence of myocardial infarction detected by electrocardiography and prevalence of peripheral arterial disease detected by ankle-arm index. When compared to western societies, we found the Ghanaians to have more proinflammatory profiles and less cardiovascular risk factors, including obesity, dysglycaemia, dyslipidaemia, and hypertension. Prevalences of cardiovascular disease were also lower. Definite myocardial infarction was present in 1.2% (95%CI: 0.6 to 2.4%). Peripheral arterial disease was present in 2.8% (95%CI: 1.9 to 4.1%).

CONCLUSIONS/SIGNIFICANCE

Taken together, our data indicate that for the pathogenesis of cardiovascular disease inflammatory processes alone do not suffice and additional factors, probably lifestyle-related, are mandatory.

Basic concepts of epigenetics: impact of environmental signals on gene expression

Through epigenetic modifications, specific long-term phenotypic consequences can arise from environmental influence on slowly evolving genomic DNA. Heritable epigenetic information regulates nucleosomal arrangement around DNA and determines patterns of gene silencing or active transcription. One of the greatest challenges in the study of epigenetics as it relates to disease is the enormous diversity of proteins, histone modifications and DNA methylation patterns associated with each unique maladaptive phenotype. This is further complicated by a limitless combination of environmental cues that could alter the epigenome of specific cell types, tissues, organs and systems. In addition, complexities arise from the interpretation of studies describing analogous but not identical processes in flies, plants, worms, yeast, ciliated protozoans, tumor cells and mammals. This review integrates fundamental basic concepts of epigenetics with specific focus on how the epigenetic machinery interacts and operates in continuity to silence or activate gene expression. Topics covered include the connection between DNA methylation, methyl-CpG-binding proteins, transcriptional repression complexes, histone residues, histone modifications that mediate gene repression or relaxation, histone core variant stability, H1 histone linker flexibility, FACT complex, nucleosomal remodeling complexes, HP1 and nuclear lamins.

Indian boarding school experience, substance use, and mental health among urban two-spirit American Indian/Alaska natives

BACKGROUND

Systematic efforts of assimilation removed many Native children from their tribal communities and placed in non-Indian-run residential schools.

OBJECTIVES

To explore substance use and mental health concerns among a community-based sample of 447 urban two-spirit American Indian/Alaska Native adults who had attended boarding school as children and/or who were raised by someone who attended boarding school.

METHOD

Eighty-two respondents who had attended Indian boarding school as children were compared to respondents with no history of boarding school with respect to mental health and substance use.

RESULTS

Former boarding school attendees reported higher rates of current illicit drug use and living with alcohol use disorder, and were significantly more likely to have attempted suicide and experienced suicidal thoughts in their lifetime compared to non-attendees. About 39% of the sample had been raised by someone who attended boarding school. People raised by boarding school attendees were significantly more likely to have a general anxiety disorder, experience posttraumatic stress disorder symptoms, and have suicidal thoughts in their lifetime compared to others.

Health disparities in endocrine disorders: biological, clinical, and nonclinical factors--an Endocrine Society scientific statement

OBJECTIVE

The aim was to provide a scholarly review of the published literature on biological, clinical, and nonclinical contributors to race/ethnic and sex disparities in endocrine disorders and to identify current gaps in knowledge as a focus for future research needs. PARTICIPANTS IN DEVELOPMENT OF SCIENTIFIC STATEMENT: The Endocrine Society's Scientific Statement Task Force (SSTF) selected the leader of the statement development group (S.H.G.). She selected an eight-member writing group with expertise in endocrinology and health disparities, which was approved by the Society. All discussions regarding the scientific statement content occurred via teleconference or written correspondence. No funding was provided to any expert or peer reviewer, and all participants volunteered their time to prepare this Scientific Statement.

EVIDENCE

The primary sources of data on global disease prevalence are from the World Health Organization. A comprehensive literature search of PubMed identified U.S. population-based studies. Search strategies combining Medical Subject Headings terms and keyword terms and phrases defined two concepts: 1) racial, ethnic, and sex differences including specific populations; and 2) the specific endocrine disorder or condition. The search identified systematic reviews, meta-analyses, large cohort and population-based studies, and original studies focusing on the prevalence and determinants of disparities in endocrine disorders. consensus process: The writing group focused on population differences in the highly prevalent endocrine diseases of type 2 diabetes mellitus and related conditions (prediabetes and diabetic complications), gestational diabetes, metabolic syndrome with a focus on obesity and dyslipidemia, thyroid disorders, osteoporosis, and vitamin D deficiency. Authors reviewed and synthesized evidence in their areas of expertise. The final statement incorporated responses to several levels of review: 1) comments of the SSTF and the Advocacy and Public Outreach Core Committee; and 2) suggestions offered by the Council and members of The Endocrine Society.

CONCLUSIONS

Several themes emerged in the statement, including a need for basic science, population-based, translational and health services studies to explore underlying mechanisms contributing to endocrine health disparities. Compared to non-Hispanic whites, non-Hispanic blacks have worse outcomes and higher mortality from certain disorders despite having a lower (e.g. macrovascular complications of diabetes mellitus and osteoporotic fractures) or similar (e.g. thyroid cancer) incidence of these disorders. Obesity is an important contributor to diabetes risk in minority populations and to sex disparities in thyroid cancer, suggesting that population interventions targeting weight loss may favorably impact a number of endocrine disorders. There are important implications regarding the definition of obesity in different race/ethnic groups, including potential underestimation of disease risk in Asian-Americans and overestimation in non-Hispanic black women. Ethnic-specific cut-points for central obesity should be determined so that clinicians can adequately assess metabolic risk. There is little evidence that genetic differences contribute significantly to race/ethnic disparities in the endocrine disorders examined. Multilevel interventions have reduced disparities in diabetes care, and these successes can be modeled to design similar interventions for other endocrine diseases.

Concepts of race and ethnicity among health researchers: patterns and implications

OBJECTIVES

This study adds to the discussion of appropriate categories of analysis in health research. We contribute data based on actual interviews about the concepts of race and ethnicity, conducted among a broad range of US health researchers.

DESIGN

In-person qualitative interviews were conducted with 73 scientists at two health research institutions, one that focused on public health research, and one that focused on research about a specific disease. This represents a larger and more interdisciplinary sample of health researchers than has been previously interviewed about these topics.

RESULTS

We identify a core model of how race and ethnicity are understood. The respondents were confused about the concepts of race and ethnicity and their link to genetic differences between populations; many treated these concepts as interchangeable and genetically based. Although ethnicity was considered somewhat more socially constructed, it was often felt to cause unhealthy behavior. In addition, the situation is not improving; the younger health researchers tended to put a stronger emphasis on the genetic aspects of race than did the older health researchers.

CONCLUSION

Unlike reviews of how these concepts are used in scientific publications in which race and ethnicity are often undefined, our face-to-face interviews with these researchers allowed an understanding of their concepts of race and ethnicity. Building on their actual perspectives, these data suggest alternative approaches to formal and continuing educational training for health researchers. We recommend beginning with discussions of human diversity, and then moving on to what race and ethnicity are - and are not.

Vitamin D3 supplementation (4000 IU/d for 1 y) eliminates differences in circulating 25-hydroxyvitamin D between African American and white men

BACKGROUND

African Americans suffer disproportionately from diabetes and cardiovascular disease and are significantly more likely to have suboptimal concentrations of circulating 25-hydroxyvitamin D [25(OH)D]. The results of epidemiologic and observational studies suggest that there is a link between vitamin D deficiency and the risk of cardiometabolic disorders, which underscores the importance of maintaining healthy concentrations of 25(OH)D.

OBJECTIVE

The objective was to investigate whether daily supplementation with 4000 IU vitamin D(3) for 1 y would eliminate any disparities in circulating concentrations of 25(OH)D between African American and white men.

DESIGN

Serum concentrations of 25(OH)D were measured every 2 mo in 47 subjects who received a daily oral dose of 4000 IU vitamin D(3) for 1 y.

RESULTS

More than 90% of African Americans had serum concentrations of 25(OH)D <32 ng/mL, and approximately two-thirds had serum concentrations <20 ng/mL. Furthermore, there were significant disparities in serum concentrations of 25(OH)D between African American and white men. Supplementation with 4000 IU/d for 1 y eliminated any significant differences in circulating concentrations of 25(OH)D between African American and white men.

CONCLUSION

The results of this clinical study show the feasibility and efficacy of this approach in the elimination of hypovitaminosis D, which is a widespread health disparity among African Americans. This trial was registered at clinicaltrials.gov as NCT01045109.

Intergenerational predictors of birth weight in the Philippines: correlations with mother's and father's birth weight and test of maternal constraint

BACKGROUND

Birth weight (BW) predicts many health outcomes, but the relative contributions of genes and environmental factors to BW remain uncertain. Some studies report stronger mother-offspring than father-offspring BW correlations, with attenuated father-offspring BW correlations when the mother is stunted. These findings have been interpreted as evidence that maternal genetic or environmental factors play an important role in determining birth size, with small maternal size constraining paternal genetic contributions to offspring BW. Here we evaluate mother-offspring and father-offspring birth weight (BW) associations and evaluate whether maternal stunting constrains genetic contributions to offspring birth size.

METHODS/PRINCIPAL FINDINGS

Data include BW of offspring (n = 1,101) born to female members (n = 382) and spouses of male members (n = 275) of a birth cohort (born 1983-84) in Metropolitan Cebu, Philippines. Regression was used to relate parental and offspring BW adjusting for confounders. Resampling testing was used to evaluate whether false paternity could explain any evidence for excess matrilineal inheritance. In a pooled model adjusting for maternal height and confounders, parental BW was a borderline-significantly stronger predictor of offspring BW in mothers compared to fathers (sex of parent interaction p = 0.068). In separate multivariate models, each kg in mother's and father's BW predicted a 271±53 g (p<0.00001) and 132±55 g (p = 0.017) increase in offspring BW, respectively. Resampling statistics suggested that false paternity rates of >25% and likely 50% would be needed to explain these differences. There was no interaction between maternal stature and maternal BW (interaction p = 0.520) or paternal BW (p = 0.545).

CONCLUSIONS/SIGNIFICANCE

Each kg change in mother's BW predicted twice the change in offspring BW as predicted by a change in father's BW, consistent with an intergenerational maternal effect on offspring BW. Evidence for excess matrilineal BW heritability at all levels of maternal stature points to indirect genetic, mitochondrial, or epigenetic maternal contributions to offspring fetal growth.

The Minority Aging Research Study: ongoing efforts to obtain brain donation in African Americans without dementia

The Minority Aging Research Study (MARS) is a longitudinal, epidemiologic cohort study of decline in cognitive function and risk of Alzheimer's disease (AD) in older African Americans, with brain donation after death added as an optional component for those willing to consider organ donation. In this manuscript, we first summarize the study design and methods of MARS. We then provide details of ongoing efforts to achieve neuropathologic data on over 100 African Americans participating in MARS and in three other clinical-pathologic cohort studies at Rush University Medical Center. The results examine strategies for recruiting and consenting African Americans without dementia; (2) efforts to maintain high rates of follow-up participation; (3) strategies for achieving high rates of agreement to brain donation; and (4) the methodology of obtaining rapid brain autopsy at death. The implications of these efforts are discussed.

Inflammatory profiles in the non-pregnant state predict offspring birth weight at Cebu: evidence for inter-generational effects of low grade inflammation

BACKGROUND

Although maternal infection and inflammation during pregnancy can adversely affect offspring birth weight (BW), whether low grade inflammation in the non-pregnant state predicts BW is unknown.

AIM

To evaluate relationships between offspring BW and pro- and anti-inflammatory factors measured in parous but non-pregnant women.

SUBJECTS AND METHODS

Data come from 234 parous Filipino females (21.5 ± 0.3 years) in the Cebu Longitudinal Health and Nutrition Survey, a population-based birth cohort in Metropolitan Cebu, Philippines. Pro-inflammatory [Interleukin-6 (IL-6), Interleukin-1 beta (IL-1β), tumour necrosis factor alpha (TNFα), C-reactive protein (CRP)] and anti-inflammatory [Interleukin-10 (IL-10)] factors were measured in fasting plasma when the women were not pregnant, and related to recalled offspring BW.

RESULTS

BW in female offspring was lower only among women with high IL-1β. Although pro-inflammatory cytokines did not predict BW in male offspring, women with higher anti-inflammatory IL-10 gave birth to larger males. Women with a combination of low inflammatory (IL-6) and high anti-inflammatory (IL-10) factors (interaction p < 0.104) gave birth to the largest males.

CONCLUSION

Immune factors measured outside of pregnancy predict offspring BW in these young women. Stable variation in inflammatory phenotype could impact the gestational environment of offspring, thus pointing to potential inter-generational effects of chronic low-grade inflammation.

Sleep is associated with the metabolic syndrome in a multi-ethnic cohort of midlife women: the SWAN Sleep Study

STUDY OBJECTIVES

We evaluated associations among subjective and objective measures of sleep and the metabolic syndrome in a multi-ethnic sample of midlife women.

DESIGN

Cross-sectional study.

SETTING

Participants' homes.

PARTICIPANTS

Caucasian (n = 158), African American (n = 125), and Chinese women (n = 57); mean age = 51 years. Age range = 46-57 years.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Metabolic syndrome was measured in the clinic and sleep quality was assessed by self-report. Indices of sleep duration, continuity/fragmentation, depth, and sleep disordered breathing were assessed by in-home polysomnography (PSG). Covariates included sociodemographics, menopausal status, use of medications that affect sleep, and self-reported health complaints and health behaviors known to influence metabolic syndrome risk. Logistic regression was used to test the hypothesis that the metabolic syndrome would be associated with increased subjective sleep complaints and PSG-assessed sleep disturbances. In univariate analyses, the metabolic syndrome was associated with decreased sleep duration and efficiency and increased NREM beta power and apnea-hypopnea index (AHI). After covariate adjustment, sleep efficiency (odds ratio [OR] = 2.06, 95% confidence interval [CI]: 1.08-3.93), NREM beta power (OR = 2.09, 95% CI: 1.09-3.98), and AHI (OR = 1.86, 95% CI: 1.40-2.48) remained significantly associated with the metabolic syndrome (odds ratio values are expressed in standard deviation units). These relationships did not differ by race.

CONCLUSIONS

Objective indices of sleep continuity, depth, and sleep disordered breathing are significant correlates of the metabolic syndrome in midlife women, independent of race, menopausal status and other factors that might otherwise account for these relationships.

Low birth weight does not predict the ontogeny of relative leg length of infants and children: an allometric analysis of the NHANES III sample

Previous research links both low birth weight (LBW) and relative leg length (RLL) to a similar set of adult pathologies, including type II diabetes, coronary vascular disease, and some cancers. Historically, LBW has been frequently used as a broad indicator of the quality of the intrauterine environment, while RLL has been considered a sensitive measure of childhood environmental quality. While these observations have been taken to suggest that these measures reflect independent exposures at different life-stages, their mutual association with a similar set of later pathologies makes this assumption less certain than it may have previously seemed. Nationally representative data from the Third National Health and Nutrition Examination Survey (NHANES III) are used to test the hypothesis that LBW predicts reductions in the development of leg length relative to stature. After controls for important socioeconomic exposures that might confound measurement of such a relationship, we find statistical and biological evidence that variation in birth weight and variation in the development of leg length relative to stature (RLL) are independent. The results suggest that these two measures may represent independent information on prenatal and postnatal environmental quality.

Epigenetics: a tool to understand diet-related cardiovascular risk?

Cardiovascular disease (CVD) is a leading cause of mortality and is projected to hold its grim record as developing countries increase their wealth. Since specific nutritional habits are important risk factors for CVD, it is imperative to understand how ingredients of risk-associated diets convert a healthy cellular transcriptional program into a pathological one. Epigenetics has enriched our view of the genome by showing that DNA-associated regulatory proteins and RNAs, together with chemical modifications of the DNA itself, determine which parts of the DNA chain are transcribed or silent in a given phase of a cell's life. This complex biological entity--the epigenome--accounts for the enormous phenotypic diversity within a multicellular organism despite its unicellular origin. Crucially, the epigenome can be modified by diet and other exogenous factors, thus suggesting that epigenetic mechanisms might underlie pathological responses to CVD risk factors. Here, we will review the current knowledge of epigenetic mechanisms in diet-gene interactions and propose ways in which epigenetics might clarify the impact of genetic variants on CVD risk.

Conceptual approaches to the study of health disparities

Scientific and policy interest in health disparities, defined as systematic, plausibly avoidable health differences adversely affecting socially disadvantaged groups, has increased markedly over the past few decades. Like other research, research in health disparities is strongly influenced by the underlying conceptual model of the hypothetical causes of disparities. Conceptual models are important and a major source of debate because multiple types of factors and processes may be involved in generating disparities, because different disciplines emphasize different types of factors, and because the conceptual model often drives what is studied, how results are interpreted, and which interventions are identified as most promising. This article reviews common conceptual approaches to health disparities including the genetic model, the fundamental cause model, the pathways model, and the interaction model. Strengths and limitations of the approaches are highlighted. The article concludes by outlining key elements and implications of an integrative systems-based conceptual model.

Allostasis and allostatic load in the context of poverty in early childhood

This paper examined the relation of early environmental adversity associated with poverty to child resting or basal level of cortisol in a prospective longitudinal sample of 1135 children seen at 7, 15, 24, 35, and 48 months of age. We found main effects for poor housing quality, African American ethnicity, and low positive caregiving behavior in which each was uniquely associated with an overall higher level of cortisol from age 7 to 48 months. We also found that two aspects of the early environment in the context of poverty, adult exits from the home and perceived economic insufficiency, were related to salivary cortisol in a time-dependent manner. The effect for the first of these, exits from the home, was consistent with the principle of allostatic load in which the effects of adversity on stress physiology accumulate over time. The effect for perceived economic insufficiency was one in which insufficiency was associated with higher levels of cortisol in infancy but with a typical but steeper decline in cortisol with age at subsequent time points.

Maternal cortisol disproportionately impacts fetal growth in male offspring: evidence from the Philippines

OBJECTIVES

Lower birth weight (BW) reoccurs across generations, but the intermediate mechanisms remain poorly understood. One potential pathway involves cortisol, which may be elevated in women born small and in turn could lead to fetal growth restriction in offspring. To test this possibility, we evaluated whether BW predicts hypothalamic-pituitary-adrenal (HPA) function in the nonpregnant state in a cohort of young Filipino women, and whether differences in HPA function predict offspring BW.

METHODS

Multiple regression relating maternal BW, adult salivary cortisol profiles and recalled offspring BW (N = 488) among participants of the Cebu Longitudinal Health and Nutrition Survey.

RESULTS

Maternal BW related inversely to evening cortisol in adulthood (P < 0.04). Maternal BW and evening cortisol were both stronger predictors of male than of female BW (maternal BW: P < 0.0001 for males; P = 0.07 for females; bedtime cortisol: P = 0.003 for males; P = 0.3 for females). Waking and 30-min postwaking cortisol did not predict offspring BW. Controlling for evening cortisol did not diminish the relationship between maternal and offspring BW in males or females.

CONCLUSIONS

Being born small predicted higher evening cortisol in adulthood among these young mothers. Lower maternal BW and elevated evening cortisol independently predicted giving birth to lower BW offspring, with effects greatest and only significant among males. We speculate that sex differences in sensitivity to maternal stress hormones could help explain the stronger relationships between BW and cardiovascular disease (CVD) risk factors reported among the males in this and other populations.

Salivary cortisol mediates effects of poverty and parenting on executive functions in early childhood

In a predominantly low-income population-based longitudinal sample of 1,292 children followed from birth, higher level of salivary cortisol assessed at ages 7, 15, and 24 months was uniquely associated with lower executive function ability and to a lesser extent IQ at age 3 years. Measures of positive and negative aspects of parenting and household risk were also uniquely related to both executive functions and IQ. The effect of positive parenting on executive functions was partially mediated through cortisol. Typical or resting level of cortisol was increased in African American relative to White participants. In combination with positive and negative parenting and household risk, cortisol mediated effects of income-to-need, maternal education, and African American ethnicity on child cognitive ability.

Ethnic Groups as Migrant Groups: Improving Understanding of Links Between Ethnicity/Race and Risk of Type 2 Diabetes and Associated Conditions

Most members of minority ethnic/racial groups in affluent western societies are recent immigrants or immediate descendants thereof. The health implications of ethnic groups also being migrant groups are important but often not fully explored. Research demonstrating developmental influences on the risk of type 2 diabetes and associated conditions suggests that migrants will differ in disease risk compared with the general population. It also leads us to expect intergenerational differences in disease risk within many minority ethnic/racial groups. Differences in health behaviors between ethnic/racial groups are also expected to change over time following migration, including across generations, but do not necessarily follow a simple model of acculturation. Understanding the ways in which the biosocial heritage of migrant groups interacts over the long term with migrants' new environments is central to understanding differences in disease risk that are identified as ethnic or racial and also highlights heterogeneity in risk within ethnic groups.

Body configuration as a predictor of mortality: comparison of five anthropometric measures in a 12 year follow-up of the Norwegian HUNT 2 study

BACKGROUND

Distribution of body fat is more important than the amount of fat as a prognostic factor for life expectancy. Despite that, body mass index (BMI) still holds its status as the most used indicator of obesity in clinical work.

METHODS

We assessed the association of five different anthropometric measures with mortality in general and cardiovascular disease (CVD) mortality in particular using Cox proportional hazards models. Predictive properties were compared by computing integrated discrimination improvement and net reclassification improvement for two different prediction models. The measures studied were BMI, waist circumference, hip circumference, waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). The study population was a prospective cohort of 62,223 Norwegians, age 20-79, followed up for mortality from 1995-1997 to the end of 2008 (mean follow-up 12.0 years) in the Nord-Trøndelag Health Study (HUNT 2).

RESULTS

After adjusting for age, smoking and physical activity WHR and WHtR were found to be the strongest predictors of death. Hazard ratios (HRs) for CVD mortality per increase in WHR of one standard deviation were 1.23 for men and 1.27 for women. For WHtR, these HRs were 1.24 for men and 1.23 for women. WHR offered the greatest integrated discrimination improvement to the prediction models studied, followed by WHtR and waist circumference. Hip circumference was in strong inverse association with mortality when adjusting for waist circumference. In all analyses, BMI had weaker association with mortality than three of the other four measures studied.

CONCLUSIONS

Our study adds further knowledge to the evidence that BMI is not the most appropriate measure of obesity in everyday clinical practice. WHR can reliably be measured and is as easy to calculate as BMI and is currently better documented than WHtR. It appears reasonable to recommend WHR as the primary measure of body composition and obesity.

Understanding the cumulative impacts of inequalities in environmental health: implications for policy

Racial or ethnic minority groups and low-income communities have poorer health outcomes than others. They are more frequently exposed to multiple environmental hazards and social stressors, including poverty, poor housing quality, and social inequality. Researchers are grappling with how best to characterize the cumulative effects of these hazards and stressors in order to help regulators and decision makers craft more-effective policies to address health and environmental disparities. In this article we synthesize the existing scientific evidence regarding the cumulative health implications of higher rates of exposure to environmental hazards, along with individual biological susceptibility and social vulnerability. We conclude that current environmental policy, which is focused narrowly on pollutants and their sources, should be broadened to take into account the cumulative impact of exposures and vulnerabilities encountered by people who live in neighborhoods consisting largely of racial or ethnic minorities or people of low socioeconomic status.