Remember This: Age Moderation of Genetic and Environmental Contributions to Verbal Episodic Memory from Midlife through Late Adulthood.

It is well documented that memory is heritable and that older adults tend to have poorer memory performance than younger adults. However, whether the magnitudes of genetic and environmental contributions to late-life verbal episodic memory ability differ from those at earlier ages remains unresolved. Twins from 12 studies participating in the Interplay of Genes and Environment in Multiple Studies (IGEMS) consortium constituted the analytic sample. Verbal episodic memory was assessed with immediate word list recall (N = 35,204 individuals; 21,792 twin pairs) and prose recall (N = 3,805 individuals; 2,028 twin pairs), with scores harmonized across studies. Average test performance was lower in successively older age groups for both measures. Twin models found significant age moderation for both measures, with total inter-individual variance increasing significantly with age, although it was not possible definitively to attribute the increase specifically to either genetic or environmental sources. Pooled results across all 12 studies were compared to results where we successively dropped each study (leave-one-out) to assure results were not due to an outlier. We conclude the models indicated an overall increase in variance for verbal episodic memory that was driven by a combination of increases in the genetic and nonshared environmental parameters that were not independently statistically significant. In contrast to reported results for other cognitive domains, differences in environmental exposures are comparatively important for verbal episodic memory, especially word list learning.

Positive Effects of Religion and Social Ties on the Health of Former NFL Athletes.

This study explores the relationship between religious service attendance, social ties, and health among former NFL players, a population with relatively high levels of religious attendance who endure physically demanding occupations. Research shows that frequent religious service attenders tend to have better health, partly because of social connections formed through religious involvement. We analyzed a sample of 1029 former NFL players. Consistent with previous research, bivariate and multivariate OLS regression models show that frequent religious attenders have statistically significantly better self-rated health. However, this relationship is moderated by social ties. Respondents who scored lower on the social ties index exhibited a stronger significant relationship between frequent religious attendance and health; those scoring higher on the social ties index exhibited no relationship between frequent attendance and health. Future research should examine how benefits of religious attendance vary depending upon strength of social relationships.

Educational attainment of same-sex and opposite-sex dizygotic twins: An individual-level pooled study of 19 twin cohorts.

Comparing twins from same- and opposite-sex pairs can provide information on potential sex differences in a variety of outcomes, including socioeconomic-related outcomes such as educational attainment. It has been suggested that this design can be applied to examine the putative role of intrauterine exposure to testosterone for educational attainment, but the evidence is still disputed. Thus, we established an international database of twin data from 11 countries with 88,290 individual dizygotic twins born over 100 years and tested for differences between twins from same- and opposite-sex dizygotic pairs in educational attainment. Effect sizes with 95% confidence intervals (CI) were estimated by linear regression models after adjusting for birth year and twin study cohort. In contrast to the hypothesis, no difference was found in women (ß = -0.05 educational years, 95% CI -0.11, 0.02). However, men with a same-sex co-twin were slightly more educated than men having an opposite-sex co-twin (ß = 0.14 educational years, 95% CI 0.07, 0.21). No consistent differences in effect sizes were found between individual twin study cohorts representing Europe, the USA, and Australia or over the cohorts born during the 20th century, during which period the sex differences in education reversed favoring women in the latest birth cohorts. Further, no interaction was found with maternal or paternal education. Our results contradict the hypothesis that there would be differences in the intrauterine testosterone levels between same-sex and opposite-sex female twins affecting education. Our findings in men may point to social dynamics within same-sex twin pairs that may benefit men in their educational careers.

Quality and Quantity of Social Support Show Differential Associations With Stress and Depression in African Americans.

Social support (SS) is typically associated with lower emotional distress (e.g., stress and depression) in individuals. However, SS is a multifaceted construct that can vary by quality, quantity (amount), and type (i.e., it can be emotional or instrumental in nature). OBJECTIVE: The current study examined the relationships between characteristics of SS, stress, and depression in aging African Americans. PARTICIPANTS: Analyses focused on data from 705 participants aged 22-92 years from the Carolina African American Twin Study of Aging. MEASUREMENTS: Measures included the quality and quantity of emotional and instrumental support received, as well as stress and depression. DESIGN: A series of univariate and increasingly complex multivariate regression models were conducted in MPlus (using the cluster option to control for family structure) to examine the relationships between SS and emotional distress variables. RESULTS: Overall, better quality of emotional SS predicted fewer depression symptoms and less perceived stress, after controlling for age, gender, socioeconomic status variables, and the other subtypes of SS. However, more instances of emotional SS were associated with higher levels of perceived stress, depression symptoms, and more stressful life events within the past year. Likewise, more instrumental SS predicted more perceived stress, while holding the other variables constant. CONCLUSION: African Americans who experience more emotional distress report more SS, but the quality of emotional support appears to play an important role in the association between reduced levels of stress and depression. These findings suggest that interventions should include approaches to reduce emotional distress as well as enhance the quality SS.

IGEMS: The Consortium on Interplay of Genes and Environment Across Multiple Studies - An Update.

The Interplay of Genes and Environment across Multiple Studies (IGEMS) is a consortium of 18 twin studies from 5 different countries (Sweden, Denmark, Finland, United States, and Australia) established to explore the nature of gene-environment (GE) interplay in functioning across the adult lifespan. Fifteen of the studies are longitudinal, with follow-up as long as 59 years after baseline. The combined data from over 76,000 participants aged 14-103 at intake (including over 10,000 monozygotic and over 17,000 dizygotic twin pairs) support two primary research emphases: (1) investigation of models of GE interplay of early life adversity, and social factors at micro and macro environmental levels and with diverse outcomes, including mortality, physical functioning and psychological functioning; and (2) improved understanding of risk and protective factors for dementia by incorporating unmeasured and measured genetic factors with a wide range of exposures measured in young adulthood, midlife and later life.

Pain, Racial Discrimination, and Depressive Symptoms among African American Women.

African American women with osteoarthritis (OA) are at high risk of experiencing pain. They report more pain than non-Hispanic White women and men of other racial/ethnic groups. This pain can limit independence and diminish their quality of life. Despite the detrimental effects that pain can have on older African American women with OA, there is a dearth of literature examining factors beyond the OA pathology that are associated with pain outcomes within this population. The purpose of this study was to examine the relationships between racial discrimination and depressive symptoms with pain intensity in African American women with OA. The sample comprised of 120 African American women, aged 50-80 years, with OA, from Texas and New Mexico. The women completed survey booklets to answer study questionnaires. We used multiple linear regression to test associations between racial discrimination, depressive symptoms, and pain intensity. We tested whether depressive symptoms mediated the relationship between racial discrimination and pain intensity by using bootstrapping. Results indicated that racial discrimination was significantly associated with pain intensity and that this relationship was mediated by depressive symptoms, even after controlling for body mass index, years of education, and length of time with OA. Both depressive symptoms and racial discrimination may be modifiable. If these modifiable factors are addressed in this population, there may be decreased pain in middle-aged and older African American women.

Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts.

Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990-1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.

Twin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age: A Pooled Study of 26 Twin Cohorts Participating in the CODATwins Project.

We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.

The Effects of Social Support on Physical Functioning in Older African Americans: Longitudinal Results from the Baltimore Study of Black Aging.

INTRODUCTION: Compared with other racial/ethnic groups, African Americans have higher rates of chronic conditions and suffer a disproportionate burden of disability. We aimed to examine the effects of social support on physical functioning among older African Americans. METHODS: We analyzed a sample of 448 urban, community-dwelling, older African Americans (aged 48-98 years) from the Baltimore Study of Black Aging. Baseline physical functioning was collected between 2006 and 2008 (wave 1), and change in physical functioning was collected between 2009 and 2011 (wave 2), physical functioning was assessed by self-reported limitations in 7 activities of daily living-eating, dressing, grooming, walking, bathing, using the toilet, and transferring in and out of bed-using a binary variable to indicate whether the individual had difficulty performing each specific activity. Social support was measured by how frequently participants provided/received goods and services, financial assistance, transportation, companionship, advice, or encouragement (never [0], rarely [1], sometimes [2], frequently [3]). Negative binomial regression models were used to test the effects of social support given, received, and a ratio (support received/support given) on physical functioning for those who improved and those who declined in physical functioning. RESULTS: Participants reported physical functioning at wave 1 (1.24, standard deviation [SD] = 1.98) and at wave 2 (0.34, SD = 0.83). Average social support given was 7.49 (SD = 3.26), and average social support received was 7.81 (SD = 3.17). Those who improved in physical function gave less social support and had lower social support ratios; social support received had no effect. Those who remained stable or declined in physical function gave more social support; neither social support received nor social ratio had an effect. CONCLUSION: Social support given and social support received as well as the ratio should be considered when seeking to understand how physical functioning changes over time among older African Americans.

Relationship Between Chronic Conditions and Disability in African American Men and Women.

BACKGROUND: Race differences in chronic conditions and disability are well established; however, little is known about the association between specific chronic conditions and disability in African Americans. This is important because African Americans have higher rates and earlier onset of both chronic conditions and disability than white Americans. METHODS: We examined the relationship between chronic conditions and disability in 602 African Americans aged 50 years and older in the Baltimore Study of Black Aging. Disability was measured using self-report of difficulty in activities of daily living (ADL). Medical conditions included diagnosed self-reports of asthma, depressive symptoms, arthritis, cancer, diabetes, cardiovascular disease (CVD), stroke, and hypertension. RESULTS: After adjusting for age, high school graduation, income, and marital status, African Americans who reported arthritis (women: odds ratio (OR)=4.87; 95% confidence interval(CI): 2.92-8.12; men: OR=2.93; 95% CI: 1.36-6.30) had higher odds of disability compared to those who did not report having arthritis. Women who reported major depressive symptoms (OR=2.59; 95% CI: 1.43-4.69) or diabetes (OR=1.83; 95% CI: 1.14-2.95) had higher odds of disability than women who did not report having these conditions. Men who reported having CVD (OR=2.77; 95% CI: 1.03-7.41) had higher odds of disability than men who did not report having CVD. CONCLUSIONS: These findings demonstrate the importance of chronic conditions in understanding disability in African Americans and how it varies by gender. Also, these findings underscore the importance of developing health promoting strategies focused on chronic disease prevention and management to delay or postpone disability in African Americans. PUBLICATION INDICES: Pubmed, Pubmed Central, Web of Science database.

The Relationship between Pain, Disability, and Sex in African Americans.

Older African Americans consistently report diminished capacities to perform activities of daily living (ADL) compared with other racial groups. The extent to which bodily pain is related to declining abilities to perform ADL/ADL disability in African Americans remains unclear, as does whether this relationship exists to the same degree in African American men and women. For nurses to provide optimal care for older African Americans, a better understanding of the relationship between bodily pain and ADL disability and how it may differ by sex is needed. The aim of this study was to examine whether pain, age, education, income, marital status and/or comorbid conditions were associated with ADL disabilities in older African American women and men. This was a cross-sectional descriptive study. The sample included 598 participants (446 women, 152 men) from the first wave of the Baltimore Study on Black Aging. African American women (odds ratio [OR] = 4.06; 95% confidence interval [CI] 2.63-6.26) and African American men (OR = 6.44; 95% CI = 2.84-14.57) who reported bodily pain had greater ADL disability than those who did not report bodily pain. Having two or more comorbid conditions also was significantly associated with ADL disability in African American women (OR = 3.95; 95% CI: 2.09-7.47). Further work is needed to understand pain differences between older African American women and men to develop interventions that can be tailored to meet the individual pain needs of both groups.

Perceived Control Predicts Pulse Pressure in African American Men: The Baltimore Study of Black Aging.

OBJECTIVE: Poorer health profiles among African American men throughout the life course evince greater rates of cardiovascular disease (CVD) and significantly earlier mortality compared with other groups. Despite growing emphasis on identifying how psychosocial factors influence disparate disease risk, little of this research has focused intently on African American men. METHODOLOGY: Using hierarchical linear regression, we explored the additive influence of stress, depression, and perceived control on pulse pressure, an established marker of CVD risk, in a sample (N = 153) of African American men (mean age = 66.73 ± 9.29) from the Baltimore Study of Black Aging (BSBA). RESULTS: After accounting for age and health status indicators, perceived control emerged as a significant predictor of pulse pressure. DISCUSSION: These findings suggest that greater belief in one's own efficacy is a protective factor for cardiovascular health among African American men. Future research should examine whether enhancing perceived control can have an appreciable impact on the immense CVD burden in this and other at-risk populations.

Vascular risk factors, depression, and cognitive change among African American older adults.

OBJECTIVE: Vascular burden has been linked to future depression and cognitive change in predominately European American samples. This study investigated these relationships in older African Americans. METHODS: To examine the connection between vascular risk factors, depression, and cognitive change, this study utilized data from 435 older African Americans. Specifically, the study examined the link between vascular risk at baseline with depression and cognitive functioning at a 2.5-year follow-up visit. RESULTS: High baseline vascular risk was associated with increased odds of future depression while controlling for age and current depression. A series of path analyses demonstrated links between baseline vascular risk, increases in depression, and decreases in processing speed. CONCLUSIONS: These findings suggest that African Americans with greater vascular burden are at greater risk for depression and cognitive change.

Associations between self-rated health and personality.

OBJECTIVE: The goal of our study was to examine how Big Five personality factors predict variability in self-rated health in a sample of older African Americans from the Baltimore Study of Black Aging. METHODS: Personality was measured by the NEO Personality Inventory-Revised, and self-rated health was assessed by the Health Problems Checklist. PARTICIPANTS: The study sample had 202 women and 87 men. Ages ranged from 49 to 90 years (M = 67.2 years, SD = 8.55), and average years of formal education was 10.8 (SD = 3.3). RESULTS: Multiple linear regressions showed that neuroticism and extraversion were significant regression predictors of self-rated health, after controlling for demographic factors. CONCLUSIONS: These findings suggest individual personality traits may influence health ratings, behaviors, and decision-making among older African Americans.

Stress, longevity and cardiovascular outcomes among African American families in the Jackson Heart Study.

OBJECTIVE: Little is known about the relationship between family longevity, stress, and CVD in African Americans. METHODOLOGY: Data consisted of 3274 participants aged ≥ 50 years with information on parental living status, the three indicators of stress, and cardiovascular health from the Jackson Heart Study (JHS). RESULTS: Those with both parents dead had significantly fewer life events than those with mother alive but father dead and those with both parents alive. Controlling for age, sex, and education, there were significant main effects for the number of life events, as well as the three parental living status variables in comparison to the both dead category. There is evidence for mediation with life events and weekly stress events, but not with global stress. DISCUSSION: The results show that there is a pattern on longevity in African American families that intersects with their stress experiences. Further examination of how generational patterns of stress are passed down is warranted.

Distinct functions of social support and cognitive function among older adults.

UNLABELLED: BACKGROUND/STUDY CONTEXT: Social support has been shown to buffer cognitive decline in older adults; however, few studies have examined the association of distinct functions of perceived social support and cognitive function. The current study examined the relations between distinct functions of social support and numerous cognitive domains in older adults. METHODS: Data were derived from a cross-sectional, correlational study of cardiovascular risk factors, cognitive function, and neuroimaging. The participants were 175 older adults with a mean age of 66.32. A number of neuropsychological tests and the Interpersonal Support Evaluation List were administered. Multiple linear regression analyses were conducted to determine cross-sectional relations of social support to cognitive function after controlling for age, gender, education, depressive symptomatology, systolic blood pressure, body mass index, total cholesterol, and fasting glucose. RESULTS: No significant positive relations were found between distinct functions of social support and cognitive function in any domain; however, inverse relations emerged such that greater social support across several functions was associated with poorer nonverbal memory and response inhibition. CONCLUSION: Results suggest that the receipt of social support may be a burden for some older adults. Within the current study, fluid cognitive abilities reflected this phenomenon. The mechanism through which social support is associated with poorer cognitive function in some domains deserves further exploration.

African-American TOMM40'523-APOE haplotypes are admixture of West African and Caucasian alleles.

BACKGROUND: Several studies have demonstrated a lower apolipoprotein E4 (APOE ε4) allele frequency in African-Americans, but yet an increased age-related prevalence of AD. An algorithm for prevention clinical trials incorporating TOMM40'523 (Translocase of Outer Mitochondria Membrane) and APOE depends on accurate TOMM40'523-APOE haplotypes. METHODS: We have compared the APOE and TOMM40'523 phased haplotype frequencies of a 9.5 kb TOMM40/APOE genomic region in West African, Caucasian, and African-American cohorts. RESULTS: African-American haplotype frequency scans of poly-T lengths connected in phase with either APOE ε4 or APOE ε3 differ from both West Africans and Caucasians and represent admixture of several distinct West African and Caucasian haplotypes. A new West African TOMM40'523 haplotype, with APOE ε4 connected to a short TOMM40'523 allele, is observed in African-Americans but not Caucasians. CONCLUSION: These data have therapeutic implications for the age of onset risk algorithm estimates and the design of a prevention trial for African-Americans or other mixed ethnic populations.

Sleep behaviors in older African American females reporting nonmalignant chronic pain: understanding the psychosocial implications of general sleep disturbance.

This study examined factors that influence sleep quality in older African American women (N = 181) reporting chronic pain. Participants completed a series of questions assessing demographic and behavioral characteristics, health status, pain intensity, and sleep disturbance. Findings indicated that younger participants and those experiencing poorer physical functioning reported more difficulty sleeping due to pain. Similarly, participants who reported being awakened from sleep due to pain were younger and experienced greater pain intensity. Understanding the relationship between sleep and pain in this group of women may be useful in promoting effective disease management and sleep awareness among patients, caregivers, and healthcare professionals.

Age and Sex Differences in the Genetic Architecture of Measures of Subjective Health: Relationships With Physical Health, Depressive Symptoms, and Episodic Memory.

OBJECTIVES: Subjective health (SH) is not just an indicator of physical health, but also reflects active cognitive processing of information about one's own health and has been associated with emotional health measures, such as neuroticism and depression. Behavior genetic approaches investigate the genetic architecture of SH, that is, genetic and environmental influences on individual differences in SH and associations with potential components such as physical, cognitive, and emotional health. Previous twin analyses have been limited by sex, sample size, age range, and focus on single covariates. METHODS: The current analysis used data from 24,173 adults ranging in age from 40 to 90 years from the international Interplay of Genes and Environment across Multiple Studies consortium to investigate the genetic architecture of 3 measures of SH: self-rated health, health compared to others, and impact of health on activities. Independent pathways model of SH included physical health, depressive symptoms, and episodic memory, with age, sex, and country included as covariates. RESULTS: Most or all of the genetic variance for SH measures were shared with physical health, depressive symptoms, and episodic memory. Genetic architecture of SH differed across measures, age groups (40-65, 66-90), and sexes. Age comparisons indicated stronger correlations with all 3 covariates in older adults, often resulting from greater shared genetic variance. DISCUSSION: The predictive value of SH has been amply demonstrated. The higher genetic contributions to associations between SH and its components in older adults support the increasing conceptualization with age of SH as an intuitive summation of one's vital reserve.

A registry of adult African American twins: the Carolina African American Twin Study of Aging.

Twin studies have seldom addressed ethnicity as one of the possible factors that create unique combinations of genetic and environmental influences. The major objective of the Carolina African American Twin Study of Aging is to identify the proportion of the genetic and environmental sources of individual variation in measures of health and behavioral factors in a sample of adult African Americans. Drawn from birth records from the State of North Carolina, this in-person study used public records to identify a cohort of twins between 22 and 92 years of age (X = 49.82 yrs, SD = 14.62), 39.7% of which were men. Members of non-intact twin pairs and siblings were also recruited to explore alternative models to the classic twin design. To date, the project has contributed to knowledge about blood pressure, forced expiratory volume, chronic illness, body mass index, and waist-hip ratio memory, personality, social, and demographic factors, mortality, and mental health.