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RationaleLittle research has evaluated the life course drivers of cognitive aging in South Africa.ObjectivesWe investigated the relationships of self-rated childhood health and father's occupation during childhood with later-life cognitive function score and whether educational attainment mediated these relationships among older South Africans living in a former region of Apartheid-era racial segregation.MethodsData were from baseline assessments of "Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community" (HAALSI), a population-based study of 5059 men and women aged ≥40 years in 2015 in rural Agincourt sub-district, South Africa. Childhood health, father's occupation during childhood, and years of education were self-reported in study interviews. Cognitive measures assessed time orientation, numeracy, and word recall, which were included in a z-standardized latent cognitive function score variable. Linear regression models adjusted for age, sex, and country of birth were used to estimate the total and direct effects of each childhood risk factor, and the indirect effects mediated by years of education.ResultsPoor childhood health predicted lower cognitive scores (total effect = -0.28; 95% CI = -0.35, -0.21, versus good); this effect was not mediated by educational attainment. Having a father in a professional job during childhood, while rare (3% of sample), predicted better cognitive scores (total effect = 0.25; 95% CI = 0.10, 0.40, versus unskilled manual labor, 29% of sample). Half of this effect was mediated by educational attainment. Education was linearly associated with later-life cognitive function score (0.09; 95% CI = 0.09, 0.10 per year achieved).ConclusionIn this post-Apartheid, rural South African context, older adults with poor self-reported childhood health or whose father worked in unskilled manual labor had relatively poor cognitive outcomes. Educational attainment strongly predicted cognitive outcomes, and appeared to be, in part, a mechanism of social stratification in later-life cognitive health in this context.

We investigated whether maternal foreign-born status confers a protective effect against low birthweight (LBW) across US Hispanic/Latino subgroups (i.e., Mexicans, Puerto Ricans, Cubans and Central/South Americans) in the USA, and whether the association between maternal education and LBW varies by Hispanic/Latino subgroup and by foreign-born status. We conducted logistic regression analyses of the 2002 US Natality Detail Data (n = 634,797). Overall, foreign-born Latino women are less likely to have LBW infants than US-born Latino women. The protective effect of foreign-born status is stronger among Latino women with less than high school education. The maternal education gradient is significantly flatter among foreign-born Latino women than among their US-born counterparts (p < 0.001). Patterns among Mexican-origin women account for the overall trends among all Latinos. Foreign-born status (main effect) reduces the risk of LBW among Mexicans by about 21% but does not protect against LBW among other Latino subgroups (i.e., Puerto Ricans, Cubans and Central/South Americans). Among Mexicans and Central South Americans, the protective effect of foreign-born status is stronger among women with low education (i.e., 0-11 and 12 years) than among women with more education (i.e., 13-15 and 16+ years). The educational gradient in LBW is less pronounced among foreign-born Mexicans and Central/South Americans than among their US-born counterparts. As such, maternal foreign-born status and education are associated with LBW, though the direction and strength of these associations vary across Latino subgroups. A 'health paradox' is apparent for foreign-born Mexican and Central/South American women among whom there is a weak maternal educational gradient in LBW. Future research may test hypotheses regarding the mechanisms underlying these variations in LBW among Latino subgroups, i.e., different gradients in sending countries, health selection of immigrants, cultural factors, and social support. Keywords: Low birthweight; Latinos; Hispanics; Education; Immigration; USA; Foreign-born mothers

Prevalence of child undernutrition remains high in many developing countries. In settings with scarce resources, modifiable maternal social conditions may influence feeding and parenting practices, in turn affecting child growth. This study aims to quantify the association between maternal social support and depression to children's physical growth outcomes in Teresina, Piaui, northeast Brazil. Interviews were conducted with a random sample of 595 mothers of children 6-24 months old in four low-income sections of Teresina, Piaui. We collected data on sociodemographic factors, mothers' social support, mothers' depressive symptomatology, and child's weight and recumbent length. Weight-for-height z-scores (WHZ), height-for-age z-scores (HAZ) and weight-for-age z-scores (WAZ) were calculated using the National Center for Chronic Disease Prevention and Health Promotion Center SAS program based on the 2000 Centers for Disease Control reference growth curves. Multivariable linear regression was used to model the association between maternal social support and depression to child growth, adjusting for biological and socio-demographic variables. Interviewer and neighborhood variation was accounted for through the inclusion of random effects. In adjusted models, material support, measured by number of friends or family members available to mothers when needing food or milk, was related to 0.3 higher average WHZ and 0.2 higher average WAZ in their children. Maternal positive social interaction, which reflects engagement in leisure-time activities with others, was associated with 0.3 higher average WHZ. Mothers' affectionate support was related to 0.2 higher average children's WHZ and WAZ, whereas social support for resolving a conflict was associated with 0.2 lower average HAZ. Maternal depression was not associated with child growth. It is concluded that inadequate growth in children may be sensitive to maternal social support. Keywords: Social support: Childhood growth; Depression; Brazil; Nutrition; Mothers

Previous research has suggested that socio-economic status (SES) differences in mortality are only partially explained by differences in life-style, psychological and social factors. Seven year mortality data (1988-1995) from the MacArthur Study of Successful Aging, a longitudinal study of adults, aged 70-79, from New Haven, CT; East Boston, MA; and Durham, NC; were used to test the hypothesis that a cumulative measure of biological dysregulation ('allostatic load'), reflecting multiple, regulatory systems, would serve as a further mediator of SES differences in mortality. Logistic regression analyses revealed that a cumulative index of biological risk explained 35.4% of the difference in mortality risk between those with higher versus lower SES (as measured by less than high school education versus high school or greater educational attainment). Importantly, the cumulative index provided independent explanatory power, over and above a measure of doctor-diagnosed disease, though the latter also contributed to education-related variation in mortality risks. The summary measure of biological risk also accounted for more variance than individual biological parameters, suggesting the potential value of a multi-systems view of biological pathways through which SES ultimately affects morbidity and mortality. Keywords: Socio-economic status; Mortality; Allostatic load; Education; USA

The purpose of this study of mid-life and older women was to assess the relation between informal care provision and depressive symptoms, taking into account concurrent demands on women's time (including multiple caregiving roles and employment outside the home) as well as participants' access to potentially supportive social ties. This cross-sectional study included women ages 46-71, free from major disease, who provided complete health and social information in the 1992 Nurses' Health Study follow-up survey (n = 61,383). In logistic regression models predicting depressive symptoms, we examined the interaction between employment outside the home and informal care provision for a disabled or ill spouse or parent. We also investigated level of social ties, measured with the Berkman-Syme Social Network Index, as a potential modifier of the association between informal care provision and depressive symptoms. In all analyses, higher weekly time commitment to informal care for a spouse or parent was associated with increased risk of depressive symptoms. This relationship persisted whether women were not employed outside the home, were employed full-time, or were employed part-time. Higher weekly time commitment to informal care provision was associated with increased risk of depressive symptoms whether women were socially integrated or socially isolated. However, both informal care provision and social ties were potent independent correlates of depressive symptoms. Therefore, women who reported high spousal care time commitment and few social ties experienced a dramatic elevation in depressive symptoms, compared to women with no spousal care responsibilities and many social ties (OR for depressive symptoms = 11.8; 95% CI 4.8, 28.9). We observed the same pattern among socially isolated women who cared for their parent(s) many hours per week, but the association was not as strong (OR for depressive symptoms = 6.5; 95% CI 3.4, 12.7). In this cross-sectional study, employment status did not seem to confer additional mental health risk or benefit to informal caregivers, while access to extensive social ties was associated with more favorable caregiver health outcomes. Keywords: Caregivers; Mental health; Depressive symptoms; Social ties; Employment; USA

Social networks and social support are strongly associated with health, yet the pathways between social relations and health are not well understood. In one of the very few studies on this issue conducted in France, we used data from the French GAZEL cohort of employees of the national gas and electricity company, to (1) explore the relationship between the structure and function of the social environment upon self-reported health and (2) test the hypothesis that social relations directly affect health. In a prospective analysis over a 12-month follow-up period, we found that a lack of social support and dissatisfaction with social relations are predictive of poor health status, while weak social networks are not. Thus, functional aspects of social relations are better predictors of poor health than the structure of social interactions. Low social support was an independent risk factor for poor health in men and women: for men the effect was strongest among individuals who held a high occupational status, for women among those in high and low occupational groups. This study suggests that in France social relations exert an independent effect on health, modified by gender and socio-economic factors. Our results indicate that both clinicians in their practice and researchers may do well to focus increased attention on the health impact of social support. Keywords: Social networks; Social support; Self-reported health; Gazel cohort; France

It is widely recognized that social relationships and affiliation have powerful effects on physical and mental health. When investigators write about the impact of social relationships on health, many terms are used loosely and interchangeably including social networks, social ties and social integration. The aim of this paper is to clarify these terms using a single framework. We discuss: (1) theoretical orientations from diverse disciplines which we believe are fundamental to advancing research in this area; (2) a set of definitions accompanied by major assessment tools; and (3) an overarching model which integrates multilevel phenomena. Theoretical orientations that we draw upon were developed by Durkheim whose work on social integration and suicide are seminal and John Bowlby, a psychiatrist who developed attachment theory in relation to child development and contemporary social network theorists. We present a conceptual model of how social networks impact health. We envision a cascading causal process beginning with the macro-social to psychobiological processes that are dynamically linked together to form the processes by which social integration effects health. We start by embedding social networks in a larger social and cultural context in which upstream forces are seen to condition network structure. Serious consideration of the larger macro-social context in which networks form and are sustained has been lacking in all but a small number of studies and is almost completely absent in studies of social network influences on health. We then move downstream to understand the influences network structure and function have on social and interpersonal behavior. We argue that networks operate at the behavioral level through four primary pathways: (1) provision of social support; (2) social influence; (3) on social engagement and attachment; and (4) access to resources and material goods. Keywords: Social integration; Social networks; Social support; Mortality; Health status; Social epidemiology

While the health promoting influences of social networks have been shown in a number of studies, little attention has been paid to measurement issues within the field of epidemiology. The purpose of this paper is to propose a new set of measures of social networks for use in epidemiological research on the elderly. We use confirmatory factor analysis to test a multidimensional model of social networks using data from a large epidemiologic study of community-dwelling adults age 65 and over (U.S.A.). Confirmatory factor analysis conducted using LISREL showed that our model provides a good fit to the data after several adjustments for correlated measurement error were introduced. Based on this analysis, we developed new measures of four dimensions and a summary index of social networks. Bivariate relationships between our new measures and several sociodemographic variables of interest are also presented. Key words - social networks, aging, psychosocial factors