Sick and tired
Does Retirement Age Impact Mortality?
Erik Hernaes et al.
Journal of Health Economics, May 2013, Pages 586-598
Abstract:
The relationship between retirement and mortality is studied with a unique administrative data set covering the full population of Norway. A series of retirement policy changes in Norway reduced the retirement age for a group of workers but not for others. Difference-in-differences estimation based on monthly birth cohorts and treatment group status show that the early retirement programme significantly reduced the retirement age; this holds true also when we account for programme substitution, for example into the disability pension. Instrumental variables estimation results show no effect on mortality of retirement age; neither do estimation results from a hazard rate model.
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Racial Disparities in Survival Among Injured Drivers
Amy Haskins, David Clark & Lori Travis
American Journal of Epidemiology, 1 March 2013, Pages 380-387
Abstract:
Prior studies on racial and ethnic disparities in survival after motor vehicle crashes have examined only population-based death rates or have been restricted to hospitalized patients. In the current study, we examined 3 components of crash survival by race/ethnicity: survival overall, survival to reach a hospital, and survival among those hospitalized. Nine years of data (from 2000 through 2008) from the National Automotive Sampling System Crashworthiness Data System were used to examine white non-Hispanic, black non-Hispanic, and Hispanic drivers aged ≥15 years with serious injuries (injury severity scores of ≥9). By using multivariable logistic regression, we found that a driver's race/ethnicity was not significantly associated with overall survival after being injured in a crash (for blacks, odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.36, 1.32; for Hispanics, OR = 1.00, 95% CI: 0.59, 1.72), and blacks and Hispanics were equally likely to survive to be treated at a hospital compared with whites (for blacks, OR = 1.00, 95% CI: 0.52, 1.93; for Hispanics, OR = 1.13, 95% CI: 0.71, 1.79). However, among patients who were treated at a hospital, blacks were 50% less likely to survive 30 days compared with whites (OR = 0.50, 95% CI: 0.33, 0.76). The disparity in survival after serious traffic injuries among blacks appears to occur after hospitalization, not in prehospital survival.
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Practices of Unregulated Tanning Facilities in Missouri: Implications for Statewide Legislation
Brundha Balaraman et al.
Pediatrics, March 2013, Pages 415 -422
Background: The incidence of skin cancer has increased in the United States, concomitant with increased UV radiation (UVR) exposure among young adults. We examined whether tanning facilities in Missouri, a state without indoor-tanning regulations, acted in accordance with the Food and Drug Administration's recommendations and consistently imparted information to potential clients about the known risks of UVR.
Methods: We conducted a statewide telephone survey of randomly selected tanning facilities in Missouri. Each tanning facility was surveyed twice, in the morning (7 AM-3 PM) and evening (3-10 PM), on different days, to determine intrasalon consistency of information provided to potential clients at different times.
Results: On average, 65% of 243 tanning-facility operators would allow children as young as 10 or 12 years old to use indoor-tanning devices, 80% claimed that indoor tanning would prevent future sunburns, and 43% claimed that there were no risks associated with indoor tanning. Intrasalon inconsistencies involved allowable age of use, and UVR exposure type and duration. Morning tanning-facility employees were more likely to allow consumers to start with maximum exposure times and UV-A-emitting devices (P < .001), whereas evening employees were more likely to allow 10- or 12-year-old children to use indoor-tanning devices (P = .008).
Conclusions: Despite increasing evidence that UVR exposure in indoor-tanning devices is associated with skin cancer, ocular damage, and premature photoaging, tanning facilities in Missouri often misinformed consumers regarding these risks and lack of health benefits and inconsistently provided information about the Food and Drug Administration's guidelines for tanning devices.
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Belinda Needham et al.
Social Science & Medicine, May 2013, Pages 1-8
Abstract:
The purpose of this study was to examine the association between socioeconomic status (SES) and leukocyte telomere length (LTL) - a marker of cell aging that has been linked to stressful life circumstances - in a nationally representative, socioeconomically and ethnically diverse sample of US adults aged 20-84. Using data from the National Health and Nutrition Examination Survey (NHANES), 1999-2002, we found that respondents who completed less than a high school education had significantly shorter telomeres than those who graduated from college. Income was not associated with LTL. African-Americans had significantly longer telomeres than whites, but there were no significant racial/ethnic differences in the association between education and telomere length. Finally, we found that the association between education and LTL was partially mediated by smoking and body mass index but not by drinking or sedentary behavior.
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Diagnosing Discrimination: Stress from Perceived Racism and the Mental and Physical Health Effects
Kathryn Freeman Anderson
Sociological Inquiry, February 2013, Pages 55-81
Abstract:
Differences in health between racial groups in the United States are significant and persistent. Many studies have documented these differences as a result of a variety of different social factors. An emerging emphasis is the impact of racism in its various forms on physical and mental health. Social stress theory conceptualizes racism as a social stresssor which can produce negative health consequences for racial minorities. This study uses binary logit and negative binomial regression models of four items from the 2004 Behavioral Risk Factor Surveillance System (BRFSS) to test social stress theory and examine the relationship between stress symptoms from perceived racism and overall health (N = 32,585). The effect of race on the experience of emotional and physical stress symptoms from racism is substantial. Furthermore, experiencing both emotional and physical stress from perceived racist treatment is an important factor in predicting the number of poor mental and physical health days, indicating that the experience of stress from perceived racism is related to overall poorer health.
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How does race get "under the skin"?: Inflammation, weathering, and metabolic problems in late life
Aniruddha Das
Social Science & Medicine, January 2013, Pages 75-83
Abstract:
Using nationally representative data from the 2005-2006 U.S. National Social Life, Health, and Aging Project, this study queries the mechanisms underlying worse metabolic outcomes - blood sugar control and cardiovascular health - among black than white men ages 57 to 85. Results indicate that contrary to much of the academic literature as well as media accounts - implicitly rooted in a "culture of irresponsibility" model - older black men's social isolation, poor health behaviors, or obesity may not play a major role in their worse metabolic problems. Instead, these outcomes seem to derive more consistently from a factor almost unexamined in the literature - chronic inflammation, arguably a biological "weathering" mechanism induced by these men's cumulative and multi-dimensional stress. These findings highlight the necessity of focusing attention not simply on proximal behavioral interventions, but on broader stress-inducing social inequalities, to reduce men's race disparities in health.
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Intergenerational Health Responses to Adverse and Enriched Environments
Lars Olov Bygren
Annual Review of Public Health, 2013, Pages 49-60
Abstract:
Health consequences of relative or absolute poverty constitute a definitive area of study in social medicine. As demonstrated in the extreme example of the Dutch Hunger Winter from 1944 to 1945, prenatal hunger can lead to adult schizophrenia and depression. A Norwegian study showed how childhood poverty resulted in a heightened risk of myocardial infarction in adulthood. In England, a study of extended impaired prenatal nutrition indicated three different types of increased cardiovascular risk at older ages. Current animal and human studies link both adverse and enriched environmental exposures to intergenerational transmission. We do not fully understand the molecular mechanisms for it; however, studies that follow up epigenetic marks within a generation combined with exploration of gametic epigenetic inheritance may help explain the prevalence of certain conditions such as cardiovascular disease, schizophrenia, and alcoholism, which have complex etiologies. Insights from these studies will be of great public health importance.
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Nataria Joseph, Karen Matthews & Hector Myers
Health Psychology, forthcoming
Objective: The long-term health impact of acute unemployment and socioeconomic resource deficit has not been shown to be unique from the effects of stable socioeconomic status (SES) and serious life circumstances, such as trauma. This study examined associations between these acute socioeconomic declines and health of hurricane survivors, independent of prehurricane SES and hurricane trauma.
Method: Participants were 215 African American adults (60% female, mean age = 39 years) living in the Greater New Orleans area at the time of Hurricane Katrina and survey 4 years later. The survey included prehurricane SES measures (i.e., education and neighborhood poverty level); acute unemployment and deficits in access to SES resources following Hurricane Katrina; and posthurricane health events (i.e., cardiometabolic events, chronic pain, posttraumatic stress disorder [PTSD], and major depressive disorder [MDD]).
Results: Acute unemployment was associated with odds of experiencing a cardiometabolic event (odds ratio [OR] = 5.65, p < .05), MDD (OR = 2.76, p < .05) and chronic pain (OR = 2.76, p < .05), whereas acute socioeconomic resource deficit was associated with odds of chronic pain (OR = 1.93, p < .001) and MDD (OR = 1.19, p < .05). Associations were independent of prehurricane SES, hurricane trauma, potentially chronic SES resource deficits, and current unemployment.
Conclusions: This study shows that acute socioeconomic decline following a natural disaster can create long-term health disparities beyond those created by prehurricane SES level and traumatic hurricane experiences. Findings suggest that early intervention postdisaster to reduce pervasive socioeconomic disruption may reduce the long-term health impact of disasters.
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How Many Infants Likely Died in Africa as a Result of the 2008-2009 Global Financial Crisis?
Jed Friedman & Norbert Schady
Health Economics, May 2013, Pages 611-622
Abstract:
The human consequences of the recent global financial crisis for the developing world are presumed to be severe, but few studies have quantified them. This letter estimates the human cost of the 2008-2009 global financial crisis in one critical dimension - infant mortality - for countries in sub-Saharan Africa. The analysis pools birth-level data, as reported in female adult retrospective birth histories from all Demographic and Health Surveys collected in sub-Saharan Africa. This results in a data set of 639,000 births to 264,000 women in 30 countries. We use regression models with flexible controls for temporal trends to assess an infant's likelihood of death as a function of fluctuations in national income. We then calculate the expected number of excess deaths by combining these estimates with growth shortfalls as a result of the crisis. The results suggest 28,000-50,000 excess infant deaths in sub-Saharan Africa in the crisis-affected year of 2009. Notably, most of these additional deaths were concentrated among girls. Policies that protect the income of poor households and that maintain critical health services during times of economic contraction may reduce the expected increase in mortality. Interventions targeted at female infants and young girls can be particularly beneficial.
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Was the Economic Crisis of 2008 Good for Icelanders? Impact on Health Behaviors
Tinna Laufey Ásgeirsdóttir et al.
Economics & Human Biology, forthcoming
Abstract:
This study uses the 2008 economic crisis in Iceland to identify the effects of a macroeconomic downturn on a range of health behaviors. We use longitudinal survey data that include pre- and post- reports from the same individuals on a range of health-compromising and health-promoting behaviors. We find that the crisis led to large and significant reductions in health-compromising behaviors (such as smoking, drinking alcohol or soft drinks, and eating sweets) and certain health-promoting behaviors (consumption of fruits and vegetables), but to increases in other health-promoting behaviors (consumption of fish oil and recommended sleep). The magnitudes of effects for smoking are somewhat larger than what has been found in past research in other contexts, while those for alcohol, fruits, and vegetables are in line with estimates from other studies. Changes in work hours, real income, financial assets, mortgage debt, and mental health, together, explain the effects of the crisis on some behaviors (such as consumption of sweets and fast food), while the effects of the crisis on most other behaviors appear to have operated largely through general price increases.
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Who Should Pay for Global Health, and How Much?
Luis Carrasco, Richard Coker & Alex Cook
PLoS Medicine, February 2013
Abstract:
Mechanisms to establish the expected financial contribution from each country to achieve the health Millennium Development Goals (MDGs) could encourage scaling-up of contributions. Mirroring global carbon permit markets to mitigate climate change, we propose a cap-and-trade system consisting of a global cost-effectiveness criterion and a disability-adjusted life year (DALY) global credit market. Under this system, high-income and middle-income countries should contribute, respectively, 74% and 26% of the additional US$36-US$45 billion annually needed to attain the health MDGs. The change relative to current contributions would vary, with some countries needing to scale-up substantially their expected annual contributions under the proposed market (e.g., US, US$7-US$10 billion; China, US$2-US$3 billion; Japan, US$2 billion; Germany, US$1.5-US$2 billion), while a few already meet or exceed their required contributions (i.e., Norway, the United Arab Emirates, Luxembourg, and the UK). A DALY tradable credit market offers the potential to increase the efficiency of global health investments while promoting international obligations to the pursuit of an agreed global common good.
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Trends and Socioeconomic Gradients in Adult Mortality around the Developing World
Damien De Walque & Deon Filmer
Population and Development Review, March 2013, Pages 1-29
Abstract:
We combine data from 84 Demographic and Health Surveys from 46 countries to analyze trends and socioeconomic differences in adult mortality, calculating mortality based on the sibling mortality reports collected from female respondents aged 15-49. The analysis yields four main findings. First, adult mortality is different from child mortality: while under-5 mortality shows a definite improving trend over time, adult mortality does not, especially in sub-Saharan Africa. The second main finding is the increase in adult mortality in sub-Saharan African countries. The increase is dramatic among those most affected by the HIV/AIDS pandemic. Mortality rates in the highest HIV-prevalence countries of southern Africa exceed those in countries that experienced episodes of armed conflict. Third, even in sub-Saharan countries where HIV prevalence is not as high, mortality rates appear to be at best stagnating, and even increasing in several cases. Finally, the main dimension along which mortality appears to differ in the aggregate is by sex. Adult mortality rates in sub-Saharan Africa have risen substantially higher for men than for women-especially so in the high HIV-prevalence countries. On the whole, the data do not show large gaps by urban/rural residence or by school attainment.
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Lauren Johns et al.
American Journal of Public Health, April 2013, Pages 733-739
Objectives: Heart disease death overreporting is problematic in New York City (NYC) and other US jurisdictions. We examined whether overreporting affects the premature (< 65 years) heart disease death rate disparity between non-Hispanic Blacks and non-Hispanic Whites in NYC.
Methods: We identified overreporting hospitals and used counts of premature heart disease deaths at reference hospitals to estimate corrected counts. We then corrected citywide, age-adjusted premature heart disease death rates among Blacks and Whites and a White-Black premature heart disease death disparity.
Results: At overreporting hospitals, 51% of the decedents were White compared with 25% at reference hospitals. Correcting the heart disease death counts at overreporting hospitals decreased the age-adjusted premature heart disease death rate 10.1% (from 41.5 to 37.3 per 100 000) among Whites compared with 4.2% (from 66.2 to 63.4 per 100 000) among Blacks. Correction increased the White-Black disparity 6.1% (from 24.6 to 26.1 per 100 000).
Conclusions: In 2008, NYC's White-Black premature heart disease death disparity was underestimated because of overreporting by hospitals serving larger proportions of Whites. Efforts to reduce overreporting may increase the observed disparity, potentially obscuring any programmatic or policy-driven advances.
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Daniel Powers
Social Science Research, forthcoming
Abstract:
We investigate three interrelated sources of change in infant mortality rates over a 20 year period using the National Center for Health Statistics (NCHS) linked birth and infant death cohort files. The effects of maternal age, maternal birth cohort, and time period of childbirth on infant mortality are estimated using a modified age/period/cohort (APC) model that identifies age, period, cohort effects. We document black-white differences in the patterning of these effects and find that maternal age effects follow the predictable U-shaped pattern, net of period and cohort, but with a less steep gradient in the black population. The largest relative maternal age-specific disparity in IMR occurs among older African American mothers. Cohort effects, while considerably smaller than age and period effects, present an interesting pattern of a modest decline in IMR among later cohorts of African American mothers coupled with an increasing IMR among the same cohorts of non-Hispanic whites. However, period effects dominate the time trends, implying that period-related technologies overwhelmingly shape U.S. infant survival in today's population. These general findings are mirrored in APC analyses carried out for several leading underlying causes of infant mortality.
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Ying Zhang et al.
PLoS ONE, April 2013
Background: The 2009 H1N1 outbreak provides an opportunity to identify strengths and weaknesses of disease surveillance and notification systems that have been implemented in the past decade.
Methods: Drawing on a systematic review of the scientific literature, official documents, websites, and news reports, we constructed a timeline differentiating three kinds of events: (1) the emergence and spread of the pH1N1 virus, (2) local health officials' awareness and understanding of the outbreak, and (3) notifications about the events and their implications. We then conducted a "critical event" analysis of the surveillance process to ascertain when health officials became aware of the epidemiologic facts of the unfolding pandemic and whether advances in surveillance notification systems hastened detection.
Results: This analysis revealed three critical events. First, medical personnel identified pH1N1in California children because of an experimental surveillance program, leading to a novel viral strain being identified by CDC. Second, Mexican officials recognized that unconnected outbreaks represented a single phenomenon. Finally, the identification of a pH1N1 outbreak in a New York City high school was hastened by awareness of the emerging pandemic. Analysis of the timeline suggests that at best the global response could have been about one week earlier (which would not have stopped spread to other countries), and could have been much later.
Conclusions: This analysis shows that investments in global surveillance and notification systems made an important difference in the 2009 H1N1 pandemic. In particular, enhanced laboratory capacity in the U.S. and Canada led to earlier detection and characterization of the 2009 H1N1. This includes enhanced capacity at the federal, state, and local levels in the U.S., as well as a trilateral agreement enabling collaboration among U.S., Canada, and Mexico. In addition, improved global notification systems contributed by helping health officials understand the relevance and importance of their own information.
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Symmetry of the face in old age reflects childhood social status
David Hope et al.
Economics & Human Biology, March 2013, Pages 236-244
Abstract:
The association of socioeconomic status (SES) with a range of lifecourse outcomes is robust, but the causes of these associations are not well understood. Research on the developmental origins of health and disease has led to the hypothesis that early developmental disturbance might permanently affect the lifecourse, accounting for some of the burden of chronic diseases such as coronary heart disease. Here we assessed developmental disturbance using bodily and facial symmetry and examined its association with socioeconomic status (SES) in childhood, and attained status at midlife. Symmetry was measured at ages 83 (facial symmetry) and 87 (bodily symmetry) in a sample of 292 individuals from the Lothian Birth Cohort 1921 (LBC1921). Structural equation models indicated that poorer SES during early development was significantly associated with lower facial symmetry (standardized path coefficient -.25, p = .03). By contrast, midlife SES was not significantly associated with symmetry. The relationship was stronger in men (-.44, p = .03) than in women (-.12, p = .37), and the effect sizes were significantly different in magnitude (p = .004). These findings suggest that SES in early life (but not later in life) is associated with developmental disturbances. Facial symmetry appears to provide an effective record of early perturbations, whereas bodily symmetry seems relatively imperturbable. As bodily and facial symmetries were sensitive to different influences, they should not be treated as interchangeable. However, markers of childhood disturbance remain many decades later, suggesting that early development may account in part for associations between SES and health through the lifecourse. Future research should clarify which elements of the environment cause these perturbations.
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Katherine Weisensee
American Journal of Human Biology, forthcoming
Objectives: This study examines the relationship between craniofacial fluctuating asymmetry and cause of death in an identified skeletal collection. This study tests the Developmental Origins of Health and Disease hypothesis using fluctuating asymmetry as the measure of developmental instability.
Methods: The skeletal sample used in this study comes from Lisbon, Portugal, and individuals in the sample were born between 1806 and 1935. This represents a period during which Lisbon was beginning to undergo the modern health transition, in which mortality from infectious disease began to decline while mortality from degenerative diseases began to increase. Approximately equal numbers of individuals in the sample died from infectious diseases, such as tuberculosis, and from degenerative diseases. Fluctuating asymmetry is examined using three-dimensional landmark data collected from 392 individuals with documented causes of death. Landmark data may provide a more robust measure of fluctuating asymmetry, although it has not often been used in studies of fluctuating asymmetry in human skeletal samples.
Results: The results of the study show that individuals who died from degenerative diseases have higher rates of fluctuating asymmetry compared to individuals who died from infectious diseases. Males also exhibit higher rates of fluctuating asymmetry compared to females.
Conclusions: The results of this study confirm earlier findings that early development has a significant impact on adult health outcomes. Furthermore, the results suggest that fluctuating asymmetry in skeletal samples may offer a means of testing the Developmental Origins of Health and Disease hypothesis.
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Month of Birth and Mortality in Sweden: A Nation-Wide Population-Based Cohort Study
Peter Ueda et al.
PLoS ONE, February 2013
Background: Month of birth - an indicator for a variety of prenatal and early postnatal exposures - has been associated with life expectancy in adulthood. On the northern hemisphere, people born in the autumn live longer than those born during the spring. Only one study has followed a population longitudinally and no study has investigated the relation between month of birth and mortality risk below 50 years.
Methods and results: In this nation-wide Swedish study, we included 6,194,745 subjects, using data from population-based health and administrative registries. The relation between month of birth (January - December) and mortality risk was assessed by fitting Cox proportional hazard regression models using attained age as the underlying time scale. Analyses were made for ages >30, >30 to 50, >50 to 80 and >80 years. Month of birth was a significant predictor of mortality in the age-spans >30, >50 to 80, and >80 years. In models adjusted for gender and education for ages >30 and >50 to 80 years, the lowest mortality was seen for people born in November and the highest mortality in those born in the spring/summer, peaking in May for mortality >30 years (25‰ excess hazard ratio compared to November, [95% confidence interval = 16-34 ]) and in April for mortality >50 to 80 years (42‰ excess hazard ratio compared to November, [95% confidence interval = 30-55]). In the ages >80 years the pattern was similar but the differences in mortality between birth months were smaller. For mortality within the age-span >30 to 50 years, results were inconclusive.
Conclusion: Month of birth is associated to risk of mortality in ages above 50 years in Sweden. Further studies should aim at clarifying the mechanisms behind this association.
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Vitamin D Status Is a Biological Determinant of Health Disparities
Tom Weishaar & Joyce Marcley Vergili
Journal of the Academy of Nutrition and Dietetics, forthcoming
Background: In human beings, dark skin requires more exposure to ultraviolet light to synthesize the same amount of vitamin D as lighter skin. It is has been repeatedly shown that at the latitude of the United States there are vitamin D disparities related to skin color. Although inadequate vitamin D status and health disparities have been associated with many of the same diseases, neither nutrition policy nor public health policy in the United States currently recognizes any role at all for vitamin D as a determinant of health disparities.
Objective: This study investigated the relationship between health, skin color, and vitamin D nutriture in the US population.
Design: The design is cross-sectional, correlational, and can be generalized to the population of the United States.
Participants: We used data from 12,505 (unweighted) subjects (3,402 non-Hispanic blacks, 3,143 Mexican Americans, and 5,960 non-Hispanic whites), aged 13 years or older, from the continuous National Health and Nutrition Examination Survey 2003-2006.
Main outcome measure: Self-rated health, a repeatedly validated indicator of objective health status, was used as a continuous measure of health.
Statistical analyses performed: Using software appropriate for the complex survey design of the National Health and Nutrition Examination Survey, the study consisted of six regression models, one predicting vitamin D status and five predicting self-rated health.
Results: Controlling for the covariates sex, interview language, country of birth, tobacco use, age, body mass index, and leisure exercise as well as the socioeconomic variables education and family income, remaining disparities in self-rated health are greatly reduced or eliminated by controlling for serum 25-hydroxyvitamin D levels.
Conclusions: We found that socioeconomic factors are the strongest determinant of skin-color based health disparities in the US population, but that it may not be possible to eliminate health disparities in the United States without eliminating the skin-color-related disparities in vitamin D nutriture.
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25-hydroxyvitamin D levels in African American and Nigerian women
Ramon Durazo-Arvizu et al.
American Journal of Human Biology, forthcoming
Objectives: African Americans (AA) have substantially lower levels of circulating 25-hydroxyvitamin D (25(OH)D) than whites. We compared population-based samples of 25(OH)D in women of African descent from Nigeria and metropolitan Chicago.
Methods: One hundred women of Yoruba ethnicity from southwest Nigeria and 94 African American women from metropolitan Chicago were recruited and compared using a standardized survey protocol and the same laboratory assay for 25(OH)D.
Results: Mean 25(OH)D levels were 64 nmol/l among the Nigerians and 29 nmol/l among the AA. Only 10% of the values were shared in common between the groups, and 76% of the Nigerians were above the currently defined threshold for adequate circulating 25(OH)D compared to 5% of the AA. Modest associations were seen between 25(OH)D and measures of obesity, although adjustment for these traits did not materially affect the group differences.
Conclusion: These data support the presumption that skin color is an adaptive trait which has evolved in part to regulate 25(OH)D. It remains undetermined, however, whether lower values observed in AA have negative health consequences.
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Childhood Conscientiousness Relates to Objectively Measured Adult Physical Health Four Decades Later
Sarah Hampson et al.
Health Psychology, forthcoming
Objective: Many life span personality-and-health models assume that childhood personality traits result in life-course pathways leading through morbidity to mortality. Although childhood conscientiousness in particular predicts mortality, there are few prospective studies that have investigated the associations between childhood personality and objective health status in adulthood. The present study tested this crucial assumption of life span models of personality and health using a comprehensive assessment of the Big Five traits in childhood (M age = 10 years) and biomarkers of health over 40 years later (M age = 51 years).
Methods: Members of the Hawaii Personality and Health Cohort (N = 753; 368 men, 385 women) underwent a medical examination at mean age 51. Their global health status was evaluated by well-established clinical indicators that were objectively measured using standard protocols, including blood pressure, lipid profile, fasting blood glucose, and body mass index. These indicators were combined to evaluate overall physiological dysregulation and grouped into five more homogeneous subcomponents (glucose intolerance, blood pressure, lipids, obesity, and medications).
Results: Lower levels of childhood conscientiousness predicted more physiological dysregulation (β = -.11, p < .05), greater obesity (β = -.10, p < .05), and worse lipid profiles (β = -.10, p < .05), after controlling for the other Big Five childhood personality traits, gender, ethnicity, parental home ownership, and adult conscientiousness.
Conclusions: These findings are consistent with a key assumption in life span models that childhood conscientiousness is associated with objective health status in older adults. They open the way for testing mechanisms by which childhood personality may influence mortality through morbidity; mechanisms that could then be targeted for intervention.
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Season of Conception in Rural Gambia Affects DNA Methylation at Putative Human Metastable Epialleles
Robert Waterland et al.
PLoS Genetics, March 2013
Abstract:
Throughout most of the mammalian genome, genetically regulated developmental programming establishes diverse yet predictable epigenetic states across differentiated cells and tissues. At metastable epialleles (MEs), conversely, epigenotype is established stochastically in the early embryo then maintained in differentiated lineages, resulting in dramatic and systemic interindividual variation in epigenetic regulation. In the mouse, maternal nutrition affects this process, with permanent phenotypic consequences for the offspring. MEs have not previously been identified in humans. Here, using an innovative 2-tissue parallel epigenomic screen, we identified putative MEs in the human genome. In autopsy samples, we showed that DNA methylation at these loci is highly correlated across tissues representing all 3 embryonic germ layer lineages. Monozygotic twin pairs exhibited substantial discordance in DNA methylation at these loci, suggesting that their epigenetic state is established stochastically. We then tested for persistent epigenetic effects of periconceptional nutrition in rural Gambians, who experience dramatic seasonal fluctuations in nutritional status. DNA methylation at MEs was elevated in individuals conceived during the nutritionally challenged rainy season, providing the first evidence of a permanent, systemic effect of periconceptional environment on human epigenotype. At MEs, epigenetic regulation in internal organs and tissues varies among individuals and can be deduced from peripheral blood DNA. MEs should therefore facilitate an improved understanding of the role of interindividual epigenetic variation in human disease.