Sex differences in age trajectories of physiological dysregulation: inflammation, metabolic syndrome, and allostatic load

Sex Differences in Melanoma

PURPOSE OF REVIEW

The goal of this review has been to elucidate the sex differences in cancer incidence and mortality in cutaneous melanoma. We have evaluated biological and behavioral research to determine where the critical questions exist.

RECENT FINDINGS

The most recent findings, through 2015, are exploratory in nature but seem to indicate that the differences are more likely due to biological variations rather than behavioral. While behavioral studies do show that women are more likely than men to seek health care and practice healthy behaviors, these differences are not sufficiently strong to explain the variation in incidence and mortality in cutaneous melanoma. Evolved differences in the immune systems of females and the role of sex steroid hormones in immunomodulation are two promising avenues for research. Studies in mice demonstrate that the newer immunotherapies are more effective in females and sex steroid hormones, such as estrogen receptor beta are inversely associated with tumor aggressiveness while testosterone increases it.

SUMMARY

Our analysis indicates that biological factors need to be investigated more thoroughly to understand the variation in incidence and mortality in cutaneous melanoma. Such understanding could lead to reducing incidence and mortality for both males and females (male incidence is 27.4 per 100,000; female 16.8 per 100,000; male mortality is 3.9 per 100,000; female mortality 1.6 per 100,000). It is most likely that behavioral differences between the sexes cannot account for the preponderance of male mortality. In addition to the important role of genetic factors, it is critical to evaluate further additional biological factors and their interactions with genetics and behavior.

Independent and joint association of obesity and metabolic syndrome with depression and inflammation

OBJECTIVE

To investigate the separate and combined associations of obesity and metabolic syndrome (MetS) with depression and the role of inflammation.

METHOD

Depression was assessed with the Patient Health Questionnaire-9 (PHQ-9) and was defined with a cutpoint of ≥10. Obesity was defined as body mass index (BMI) ≥30 kg/m2 from measured height and weight. MetS was defined based on the American Heart Association consensus definition. Participants were divided into four groups: healthy normal weight (MHN), metabolically healthy obese (MHO), metabolically unhealthy normal weight (MUN), and metabolic unhealthy obese (MUO). C-Reactive protein was assessed in a subsample.

RESULTS

A total of 18,025 subjects were included in the analysis. Participants with MUO had the highest prevalence of depression compared with the MHN group (14.8% vs. 6.8, p < .001). While both obesity and MetS were independently associated with depression, there was a significant interaction between the two (p < .001), indicating that the associations of obesity and MetS with depression were synergistic. After adjusting for baseline characteristics, compared with the MHN group, the MUO group had the highest odds of depression (odds ratio [OR] = 2.30, 95% CI [2.03, 2.61]), followed by MHO group (OR = 1.51, 95% CI [1.30, 1.74]) and the MUN group (OR = 1.39, 95% CI [1.18, 1.64]). The MUO group also showed the highest level of C-reactive protein, and the latter partially mediated the effect between MUO and depressive symptoms (20.5% of the total effect).

CONCLUSION

Both obesity and MetS are associated with depression independent of each other, but when present together, these conditions have a synergistic association with depression. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Foreign-Born Hispanic Women's Health Patterns in Allostatic Load Converge to U.S.-Born Hispanic Women at a Slower Tempo Compared With Men

OBJECTIVES

We investigated the patterns of foreign-born Hispanic health convergence to U.S.-born Hispanics using an allostatic load index, a subjective biological risk health profile, and we explored whether the health convergence patterns differ by sex.

METHODS

The analytic sample consisted of 3,347 Hispanics from the pooled 2005-2010 National Health and Nutrition Examination Survey. We used negative binomial regression models to investigate the association between duration in the United States and the allostatic load index, while controlling for potential covariates.

RESULTS

Foreign-born Hispanics who had lived in the United States for 0-9 years and 10-19 years had lower levels of allostatic load than U.S.-born Hispanics; however, those who had lived in the United States for 20 or more years had a level of allostatic load similar to their U.S.-born counterparts. The pattern of immigrant health convergence shows a clear sex difference. In the sex-stratified models, we found that foreign-born Hispanic men converged to the level of allostatic load of U.S.-born Hispanic men after having lived in the United States for approximately 10 years. The health convergence pattern qualitatively differed for foreign-born Hispanic women, who remained healthier than U.S.-born Hispanic women regardless of duration in the United States.

CONCLUSIONS

Foreign-born Hispanics are healthier than their U.S.-born counterparts, providing support for the healthy migrant hypothesis. This relatively better health of foreign-born Hispanics disappears with a longer duration in the United States, providing support for the health convergence hypothesis, but is most noticeable for men. Foreign-born Hispanic women converge to U.S.-born Hispanic women's health status at a slower tempo, compared with foreign-born Hispanic men.

Association between neutrophil to lymphocyte ratio and depressive symptoms among Chinese adults: A population study from the TCLSIH cohort study

BACKGROUND

The prevalence of depression in the general population has risen sharply over the past few decades and has become a major health problem throughout the world. Increasing evidence suggests that inflammation plays an important role in the pathogenesis of depression. To better understand the role of inflammation in the pathogenesis of depression we can use the neutrophil-to-lymphocyte ratio (NLR) because it is a simple and effective marker of inflammation and immunity.

METHODS

This cross-sectional study was conducted among adults from the healthy general population in Tianjin, China. NLR was measured according to the complete blood count. Depressive symptoms were assessed using the Zung Self-Rating Depression Scale (SDS), and a cutoff score of 45 was used to indicate the presence of depressive symptoms in the study participants. The relationship between NLR and the prevalence of depressive symptoms was evaluated separately for men and women using the multiple logistic regression analysis.

RESULTS

In the present study, the overall prevalence of depressive symptoms was 17.0% among all participants. In women, the multivariable-adjusted OR of having depressive symptoms was 1.28 (95% CI 1.10, 1.49; p for trend <0.01) for the fifth compared with the first quintile of NLR, and was 1.22 (95% CI 1.07,1.39; p < 0.01) per unit increase of NLR. However, no significant association was found between NLR and depressive symptoms in men.

CONCLUSION

This study suggests that increased NLR levels are independently related to depressive symptoms in women, but not in men. Further research is required to investigate this relationship with longitudinal data to establish the temporal ordering between these variables.

Men Sustain Higher Dysregulation Levels Than Women Without Becoming Frail

The aging process differs in important ways between the sexes, with women living longer but at higher risk for frailty (the male-female health-survival paradox). The underlying biological mechanisms remain poorly understood, but may relate to sex differences in physiological dysregulation patterns. Here, using biomarkers from two longitudinal cohort studies (InCHIANTI and BLSA) and one cross-sectional survey (NHANES), we assess sex differences in trajectories of dysregulation globally and for five physiological systems: oxygen transport, electrolytes, hematopoiesis, lipids, and liver/kidney function. We found higher dysregulation levels in men, both globally and in the oxygen transport and hematopoietic systems (p < .001 for all), though differences for other systems were mixed (electrolytes) or absent (lipids and liver/kidney). There was no clear evidence for sex differences in rates of change in dysregulation with age. Although risk of frailty and mortality increase with dysregulation, there was no evidence for differences in these effects between sexes. These findings imply that the greater susceptibility of women to frailty is not simply due to a tolerance for higher dysregulation; rather, it may actually be men that have a greater tolerance for dysregulation, creating a male-female dysregulation-frailty paradox. However, the precise physiological mechanisms underlying the sex differences appear to be diffuse and hard to pin down.

Conservation of physiological dysregulation signatures of aging across primates

Two major goals in the current biology of aging are to identify general mechanisms underlying the aging process and to explain species differences in aging. Recent research in humans suggests that one important driver of aging is dysregulation, the progressive loss of homeostasis in complex biological networks. Yet, there is a lack of comparative data for this hypothesis, and we do not know whether dysregulation is widely associated with aging or how well signals of homeostasis are conserved. To address this knowledge gap, we use unusually detailed longitudinal biomarker data from 10 species of nonhuman primates housed in research centers and data from two human populations to test the hypotheses that (a) greater dysregulation is associated with aging across primates and (b) physiological states characterizing homeostasis are conserved across primates to degrees associated with phylogenetic proximity. To evaluate dysregulation, we employed a multivariate distance measure, calculated from sets of biomarkers, that is associated with aging and mortality in human populations. Dysregulation scores positively correlated with age and risk of mortality in most nonhuman primates studied, and signals of homeostatic state were significantly conserved across species, declining with phylogenetic distance. Our study provides the first broad demonstration of physiological dysregulation associated with aging and mortality risk in multiple nonhuman primates. Our results also imply that emergent signals of homeostasis are evolutionarily conserved, although with notable variation among species, and suggest promising directions for future comparative studies on dysregulation and the aging process.

Allostatic Load: Importance, Markers, and Score Determination in Minority and Disparity Populations

Allostatic load is a physiological measure of the cumulative burden of stress on the body assessed by markers of physiological dysregulation. It is a multisystem construct that quantifies biological risk which leads to poor health and maladaptive trajectories. In this overview, which is based on a presentation made at the Flip the Script: Understanding African American Women's Resilience in the Face of Allostatic Load meeting at Ohio State University in August 2018, we build upon previous reviews by discussing four key aspects of allostatic load, specifically its: (1) importance, (2) operationalization, (3) use in minority health and health disparities research, and (4) value in such research. Operationalized in various ways, allostatic load is composed of 10 original markers and additional markers deriving from research among minority and disparity populations. The markers represent four biological systems: (1) cardiovascular, (2) metabolic, (3) inflammatory, and (4) neuroendocrine. System-specific racial/ethnic and sex-based differences have been observed. An overall score can be determined using sample-generated or empirically derived clinically relevant cut points. In summary, allostatic load provides an overall and a body system-specific mechanistic link between exposures to stressors and health outcomes that may help explain health disparities among minority populations.

Association between allostatic load and health behaviours: a latent class approach

Background

Allostatic load (AL) has been characterised in many ways throughout the literature; however, its relationship to health behaviours has only been studied in limited populations. We aimed to uncover qualitative patterns of biological indicators in AL and determine if those patterns were associated with certain health behaviours.

Methods

We conducted latent class analysis using biological indicators from a multiethnic population. We fit latent class regression of class on health behaviours (smoking, poor diet, physical activity and alcohol use) to measure the association between each latent class of AL and each health behaviour.

Results

Four classes, ‘Metabolic+Cholesterol, ‘Blood Pressure’, ‘Metabolic+Blood Pressure’ and ‘Low’, were found in the sample. Latent class regression showed that physical activity and alcohol use were significantly associated with the ‘Metabolic+Blood Pressure’ class.

Conclusion

Less physical activity was required to improve AL than was previously found. Low to moderate alcohol use was beneficial for lower AL. Implications of the amount of physical activity necessary to lower AL is discussed.

Neighbourhood characteristics and cumulative biological risk: evidence from the Jamaica Health and Lifestyle Survey 2008: a cross-sectional study

OBJECTIVE

To examine whether neighbourhood characteristics are associated with cumulative biological risk (CBR) and sex differences in CBR in a nationally representative sample in Jamaica, a small island developing country with increasing prevalence of non-communicable diseases (NCDs).

DESIGN

Cross-sectional study SETTING: A population-based cross-sectional survey, the Jamaica Health and Lifestyle Survey 2008 (JHLS II) recruited persons at their homes over a 4 month period from all 14 parishes and 113 neighbourhoods defined as enumeration districts (EDs).

PARTICIPANTS

2544 persons aged 15-74 years old from the 2008 Jamaica Health and Lifestyle Survey (JHLS II), who completed interviewer-administered questionnaires and had biomarkers assessed, and whose home addresses could be reliably geocoded.

PRIMARY OUTCOME

A summary measure CBR was created using seven markers-systolic and diastolic blood pressure readings, waist circumference, body mass index, total cholesterol, fasting blood glucose levels and self-reported asthma. Weighted multilevel models examined clustering, using the intraclass correlation coefficient (ICC), of CBR across neighbourhoods and the impact of neighbourhood characteristics (recreational space availability and neighbourhood disorder) on CBR.

RESULTS

Women had significantly higher mean CBR scores than men across all age groups. There was significant clustering of CBR by ED, and among women versus men (ICC: F=6.9%, M=0.7%). Women living in more disordered neighbourhoods were 26% more likely to have high CBR as those in less disordered ones (aOR=1.26, 95% CI=1.08 to 1.47; p<0.05). Individuals living in EDs with greater recreational space availability were 25% less likely to have a high CBR (aOR=0.75, 95% CI=0.64 to 0.90; p<0.05).

CONCLUSIONS

Policy-makers in Jamaica should pay greater attention to neighbourhood factors such as recreational space availability and neighbourhood disorder that may contribute to CBR in any effort to curtail the epidemic of NCDs.

Differences between Men and Women in Mortality and the Health Dimensions of the Morbidity Process

BACKGROUND

Do men have worse health than women? This question is addressed by examining sex differences in mortality and the health dimensions of the morbidity process that characterize health change with age. We also discuss health differences across historical time and between countries.

CONTENT

Results from national-level surveys and data systems are used to identify male/female differences in mortality rates, prevalence of diseases, physical functioning, and indicators of physiological status. Male/female differences in health outcomes depend on epidemiological and social circumstances and behaviors, and many are not consistent across historical time and between countries. In all countries, male life expectancy is now lower than female life expectancy, but this was not true in the past. In most countries, women have more problems performing instrumental activities of daily living, and men do better in measured performance of functioning. Men tend to have more cardiovascular diseases; women, more inflammatory-related diseases. Sex differences in major cardiovascular risk factors vary between countries-men tend to have more hypertension; women, more raised lipids. Indicators of physiological dysregulation indicate greater inflammatory activity for women and generally higher cardiovascular risk for men, although women have higher or similar cardiovascular risk in some markers depending on the historical time and country.

SUMMARY

In some aspects of health, men do worse; in others, women do worse. The lack of consistency across historical times and between countries in sex differences in health points to the complexity and the substantial challenges in extrapolating future trends in sex differences.

Inflammation in individuals with schizophrenia - Implications for neurocognition and daily function

Individuals with schizophrenia display substantial deficits in neurocognition, resulting in poor daily functioning and disability. Recent reports have suggested that neurocognitive dysfunction in this population is linked to increased inflammation. However, there is paucity of evidence supporting this link, as well as lack of information about the putative link of inflammation to daily functioning. We examined neurocognition (MCCB) and daily functioning (SLOF), as well as inflammatory markers (TNF-α, IL-6, IL-1β, and IL-12p70) in 41 individuals with schizophrenia. Poor neurocognition was significantly associated with increased peripheral TNF-α and IL-12p70 (r = -0.44 and r = -0.38, respectively, controlling for BMI, depression and antipsychotic medication). Notably, difficulties with daily functioning were significantly associated with increased peripheral TNF-α (r = -0.51) and a trend with increased IL-12p70. Our findings support previous hypotheses linking neurocognitive impairment to increased inflammation in individuals with schizophrenia. Our results extend these associations in this population, linking inflammation to poor daily functioning in this population.

Trajectories of allostatic load among older Americans and Britons: longitudinal cohort studies

BACKGROUND

Difference in life expectancy between males and females has been suggested to rest on sex difference in physiological dysregulation. But allostatic load, a physiological index, has not been carefully examined for an extended period beyond middle age. We aim to draw longitudinal trajectories of allostatic load in a national sample of older Americans and Britons; also to examine sex-based trajectories and factors behind their differences.

METHODS

We studied men and women aged ≥50 years participating in the Health and Retirement Study Waves 8-11, 2006-2012 (N = 15,583 person-years) and the English Longitudinal Study of Ageing Waves 2, 4 and 6, 2004-2012 (N = 14,765 person-years). Because of the difference in provenance, we included different number of biomarkers to calculate allostatic load in HRS and ELSA. In HRS we used 8 biomarkers (systolic and diastolic blood pressure, haemoglobin A1c, high-density lipoprotein, total cholesterol, waist circumference, cystatin C, and C-reactive protein), while ELSA allostatic load was constructed from 10 biomarkers (systolic and diastolic blood pressure, haemoglobin A1c, high-density lipoprotein, total cholesterol, waist circumference, BMI, triglyceride, fibrinogen and C-reactive protein). A growth curve model was fitted to repeated observations of allostatic load, demographic characteristics, socioeconomic position, comorbidities and health behaviours (smoking, drinking, and physical exercise). To account for attrition, a joint model was applied.

RESULTS

The analysis showed that allostatic load increases linearly with age in the U.S. However, there are different levels for males and females. In England allostatic load follows such different paths that their trajectories cross in later life.

CONCLUSIONS

Sex-based trajectories of allostatic load showed distinct female advantage and are mostly consistent with female advantage in life expectancy.

The involvement of estrogen receptors α and β in the in vitro effects of 17β-estradiol on secretory profile of peritoneal macrophages from naturally menopausal female and middle-aged male rats

The systemic and extra- gonadal levels of 17β-estradiol (E2) change during aging, and affect the expression of estrogen receptors (ERs) in the immune cells of both females and males. The age-related cessation of ovarian function in females, as well as the tissue-specific expression of enzyme aromatase (estrogen synthase which significantly rises with the advancing age) in both males and females, both determine the concentration of E2 to which immune cells may be exposed. The present study was set up to investigate the direct influence of E2 in vitro on the secretory profile of peritoneal macrophages from young and naturally menopausal female rats, and from young and middle-aged male rats. The involvement of receptor(s) responsible for mediating the effects of E2 in vitro was examined by use of antagonists specific for ERα or ERβ. Whereas in macrophages from young female rats E2 treatment diminished interleukin (IL)-1β secretion, it increased it in young males, and the middle-aged females. The in vitro E2 treatment increased tumor necrosis factor (TNF)-α release by macrophages from young rats of both sexes, while it increased macrophage IL-6 release independently of both sex and age. At the same time, E2 decreased hydrogen peroxide (H₂O₂) production in macrophages from females, and increased it in male rats of both ages, whereas it diminished nitric oxide (NO) release in all experimental groups. Inspite of the sex- and age-specific effects of E2 on macrophage urea release, E2 did not affect the NO/urea ratio in macrophages from female rats, and diminished it in macrophages from both young and middle-aged male rats. Independently of the sex and age, E2 stimulated the release of inflammatory cytokines predominantly via macrophage ERα, and inhibited the IL-1β release in young females via ERβ. In contrast, E2 increased macrophage H₂O₂ and urea production by activating ERβ, but diminished their release via ERα. Our study may contribute to better understanding of the complex role(s) that E2 may play in innate immunity during aging, and that are dependent of sex.

Relationships between low-grade peripheral inflammation and psychotropic drugs in schizophrenia: results from the national FACE-SZ cohort

Low-grade inflammation has repeatedly been associated with schizophrenia (SZ) and in particular with cognitive impairment. Female gender, overweight and tobacco smoking have been suggested as risk factors to increase inflammation while preclinical inconsistent findings have been found regarding the association with psychotropic drugs. The aim of this study was to explore if psychotropic drugs were associated with inflammation in SZ and to determine which psychotropic drug was associated with inflammation in stable SZ subjects while considering clinical confounding factors. Participants were consecutively included in the network of the FondaMental Expert Centers for Schizophrenia and received a thorough clinical assessment, including recording of current treatment. High-sensitivity CRP (hs-CRP) was measured for each participant as a proxy to define peripheral low-grade inflammation. The zero-inflated Poisson regression model estimated the relationship between low-grade inflammation and psychotropic drug. Four hundred and five stabilized, community-dwelling SZ subjects (mean age = 32.6 years, 74% male gender) have been included. In total, 148 participants (36.5%) were found with undetectable blood hs-CRP level. The probability of having an undetectable CRP was associated with a lower body mass index (p < 0.0001) and no cyamemazine add-on antipsychotic therapy (p = 0.001). The other 257 participants (63.5%) were found to have low-grade inflammation (hs-CRP > 0 mg/L). Low-grade inflammation was significantly associated with female gender (p = 0.004), higher body mass index (p < 0.0001), current tobacco smoking (p < 0.0001), clomipramine (p = 0.04), quetiapine (p < 0.0001) and hypnotic (p = 0.0006) consumption while decreased hs-CRP blood levels was associated with aripiprazole (p = 0.004) and valproate/valpromide (p = 0.03) consumption. The present study suggests that some psychotropic drugs (quetiapine, cyamemazine, clomipramine) may be associated with increased peripheral low-grade inflammation in SZ patients while others (aripiprazole, valproate) may be associated with decreased peripheral low-grade inflammation. These results should be replicated in SZ and non-SZ populations and the biological underpinnings should be further explored.

The Intersection of Sex Differences, Tobacco Use, and Inflammation: Implications for Psychiatric Disorders

PURPOSE OF REVIEW

Tobacco use, sex differences, and psychiatric disorders are associated with altered immune function. There are also sex differences in tobacco use and psychiatric disorders. This review summarizes findings from the small, but growing literature examining sex differences in the effects of tobacco use on inflammation and the implications for psychiatric disorders.

RECENT FINDINGS

We identified four studies that tested the interaction between sex and tobacco/nicotine on inflammation. Although males and females generally exhibited differential tobacco-induced immune responses, the pattern varied depending on the sample (rodents vs. humans) and the method to evaluate inflammation. Evidence suggests that sex modulates the effects of tobacco smoke on inflammation. Many inflammation markers associated with sex differences and tobacco use are related to psychiatric disorders. We propose a model in which sex, tobacco use, and inflammation interact to increase risk for psychiatric disorders. Future studies are needed to examine the mechanisms that explain this relationship.

The Confluence of Sex Hormones and Aging on Immunity

The immune systems of post-pubescent males and females differ significantly with profound consequences to health and disease. In many cases, sex-specific differences in the immune responses of young adults are also apparent in aged men and women. Moreover, as in young adults, aged women develop several late-adult onset autoimmune conditions more frequently than do men, while aged men continue to develop many cancers to a greater extent than aged women. However, sex differences in the immune systems of aged individuals have not been extensively investigated and data addressing the effectiveness of vaccinations and immunotherapies in aged men and women are scarce. In this review, we evaluate age- and sex hormone-related changes to innate and adaptive immunity, with consideration about how this impacts age- and sex-associated changes in the incidence and pathogenesis of autoimmunity and cancer as well as the efficacy of vaccination and cancer immunotherapy. We conclude that future preclinical and clinical studies should consider age and sex to better understand the ways in which these characteristics intersect with immune function and the resulting consequences for autoimmunity, cancer, and therapeutic interventions.

Allostatic load as a predictor of grey matter volume and white matter integrity in old age: The Whitehall II MRI study

The allostatic load index quantifies the cumulative multisystem physiological response to chronic everyday stress, and includes cardiovascular, metabolic and inflammatory measures. Despite its central role in the stress response, research of the effect of allostatic load on the ageing brain has been limited. We investigated the relation of mid-life allostatic load index and multifactorial predictors of stroke (Framingham stroke risk) and diabetes (metabolic syndrome) with voxelwise structural grey and white matter brain integrity measures in the ageing Whitehall II cohort (N = 349, mean age = 69.6 (SD 5.2) years, N (male) = 281 (80.5%), mean follow-up before scan = 21.4 (SD 0.82) years). Higher levels of all three markers were significantly associated with lower grey matter density. Only higher Framingham stroke risk was significantly associated with lower white matter integrity (low fractional anisotropy and high mean diffusivity). Our findings provide some empirical support for the concept of allostatic load, linking the effect of everyday stress on the body with features of the ageing human brain.

Gender Differences in Biological Function in Young Adulthood: An Intragenerational Perspective

Sex/gender differences in health are a function of social and biological factors, and their interplay over the life course. Despite a large body of research documenting sex/gender as a determinant of health behavior and outcomes, far less scholarship examines how these differences are reflected in physiologic function-an important mediator through which social experiences "get under the skin"-in young adulthood. Using nationally representative, longitudinal data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), we examine the relationship between gender and biological function (inflammation and immunosuppression) in young adulthood. Second, we examine the contribution of social and economic circumstances in childhood and early adulthood to gender differences in health. The findings reveal strong gender differences in physiologic function, which are robust to the inclusion of many indicators of the social environment, in both inflammation and immune function.

Gender differences in the pathways from childhood disadvantage to metabolic syndrome in adulthood: An examination of health lifestyles

We investigate whether socioeconomic status (SES) in childhood shapes adult health lifestyles in domains of physical activity (leisure, work, chores) and diet (servings of healthy [i.e., nutrient-dense] vs. unhealthy [energy-dense] foods). Physical activity and food choices vary by gender and are key factors in the development of metabolic syndrome (MetS). Thus, we examined gender differences in the intervening role of these behaviors in linking early-life SES and MetS in adulthood. We used survey data (n = 1054) from two waves of the Midlife in the U.S. Study (MIDUS 1 and 2) and biomarker data collected at MIDUS 2. Results show that individuals who were disadvantaged in early life are more likely to participate in physical activity related to work or chores, but less likely to participate in leisure-time physical activity, the domain most consistently linked with health benefits. Women from low SES families were exceedingly less likely to complete recommended amounts of physical activity through leisure. Men from low SES consumed more servings of unhealthy foods and fewer servings of healthy foods. The observed associations between childhood SES and health lifestyles in adulthood persist even after controlling for adult SES. For men, lack of leisure-time physical activity and unhealthy food consumption largely explained the association between early-life disadvantage and MetS. For women, leisure-time physical activity partially accounted for the association, with the direct effect of childhood SES remaining significant. Evidence that material deprivation in early life compromises metabolic health in adulthood calls for policy attention to improve economic conditions for disadvantaged families with young children where behavioral pathways (including gender differences therein) may be shaped. The findings also underscore the need to develop gender-specific interventions in adulthood.

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Physical activity and healthy diet have been recommended to prevent/treat metabolic syndrome (MetS).

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Childhood SES is associated with development of MetS via physical activity and diet.

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Gender is key to understanding the behavioral pathways linking childhood SES and MetS.

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Low childhood SES is associated with unhealthy diet for men and insufficient leisure-time activity for both genders.

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Leisure-time activity and unhealthy diet mediate the effect of childhood SES on MetS, particularly for men.

Social Disadvantage, Severe Child Abuse, and Biological Profiles in Adulthood

Guided by the stress process model and the life course perspective, we hypothesize: (1) that childhood abuse is concentrated, in terms of type and intensity, among socially disadvantaged individuals, and (2) that experiencing serious abuse contributes to poor biological profiles in multiple body systems in adulthood. Data came from the Biomarker subsample of Midlife in the United States (2004-2006). We used latent class analysis to identify distinct profiles of childhood abuse, each reflecting a combination of type and severity. Results indicate that disadvantaged groups, women, and those from disadvantaged families are at greater risk of experiencing more severe and multiple types of abuse. Those with more severe and multifaceted childhood abuse show greater physiological dysregulation. Childhood abuse experiences partially accounted for the social status differences in physiological profiles. Our findings underscore that differential exposure to serious childhood stressors plays a significant role in gender and class inequalities in adult health.

Social Inequalities in Inflammation: Age Variations in Older Persons

OBJECTIVE

Systemic inflammation is an important risk factor for cardiovascular diseases and inequalities by race/ethnicity, gender, and education have been documented. However, there is incomplete knowledge as to how these disparities present across age, especially in late life. This study assesses whether differences in C-reactive protein (CRP), a marker of inflammation, are contingent on age among older persons.

METHOD

Data are from the 2006/2008 Health and Retirement Study ( n = 10,974) biomarker assessment. CRP was regressed on interactions between age and other status characteristics.

RESULTS

Racial/ethnic differences in inflammation do not vary significantly by age. However, gender and education differences are greatest at younger ages and then narrow steadily with increasing age.

DISCUSSION

There is considerable heterogeneity in how disparities in inflammation present across age and characteristics such as race/ethnicity, gender, and education. Understanding status differences in the influence of age on factors affecting late-life health is useful for health disparities research.

Index of cardiometabolic health: a new method of measuring allostatic load using electronic health records

OBJECTIVE

We developed a measure of allostatic load from electronic medical records (EMRs), which we named "Index of Cardiometabolic Health" (ICMH).

METHODS

Data were collected from participants' EMRs and a written survey in 2005. We computed allostatic load scores using the ICMH score and two previously described approaches.

RESULTS

We included 1865 employed adults who were 25-59 years old. Although the magnitude of the association was small, all methods of were predictive of SF-12 physical component subscales (all p < 0.001).

CONCLUSION

We found that the ICMH had similar relationships with health-related quality of life as previously reported in the literature.

Does one size fit all? The role of body mass index and waist circumference in systemic inflammation in midlife by race and gender

OBJECTIVE

This study investigates the associations of body mass index (BMI) and waist circumference (WC) with markers of systemic inflammation in midlife by race and gender.

DESIGN

Data were obtained from the Survey of Midlife in the United States, a cross-sectional, observational study of Americans 35 years old or older (White men: N = 410; White women: N = 490; Black men: N = 58; Black women: N = 117). Inflammation was measured by concentrations of fibrinogen and C-reactive protein (CRP) in fasting plasma and concentrations of E-selectin and interleukin-6 (IL-6) in fasting serum. Anthropometric data were used to obtain BMI and WC. Socio-demographic and health-related factors were assessed with a survey. Multivariate models by race and gender were estimated to test the roles of BMI and WC for each inflammation marker.

RESULTS

Compared to White men, Black women have higher BMI and higher levels of all four inflammation markers; White women have lower BMI, lower WC, and lower E-selectin and fibrinogen but higher CRP; and Black men have higher fibrinogen. After adjusting for socio-demographic and health-related covariates as well as perceived discrimination, WC is associated with all four markers of inflammation among White men and women; with three markers (fibrinogen, CRP, and IL-6) of inflammation among Black women; and with CRP (and marginally with fibrinogen and E-selectin) among Black men. BMI is associated with higher CRP and fibrinogen among Black men (marginally so for White men) but not for women of either race.

CONCLUSIONS

WC shows more consistent associations with inflammation markers than BMI, although the relationships vary by inflammation marker and population group. Our findings suggest that WC is a risk factor for systemic inflammation among White and Black men and women, and BMI is an additional risk factor for Black men.

Social Relationships and Inflammatory Markers in the MIDUS Cohort: The Role of Age and Gender Differences

OBJECTIVE

To better understand age and gender differences in associations of social relationships with chronic inflammation.

METHOD

Using a sample of middle-aged and older adults ( N = 963) from the Midlife Development in the United States (MIDUS) biomarker project, we examined interactions of age and gender with structural and functional social network measures in predicting interleukin-6 (IL-6) and C-reactive protein (CRP).

RESULTS

Significant interactions involving age and gender showed that social support was associated with lower IL-6 in older women, whereas perceived positive relationships and social integration were related to lower IL-6 in both men and women of advanced age. Functional measures were associated with higher CRP in both men and women after adjustment for health conditions and behaviors, with some further variation by age.

DISCUSSION

Greater social support may be related to lower IL-6 in older women. Further research is needed to understand observed associations of social support with higher CRP.

Sex-Based Differences in the Determinants of Old Age Life Expectancy: The Influence of Perimenopause

Studies using the sensitive periods framework typically examine the effects of early life exposures on later life health, due to the significant growth and development occurring during the first few years of life. The menopausal transition (i.e., perimenopause) is similarly characterized by rapid physiological change, yet rarely has been tested as a sensitive window in adulthood. Cohort mortality data drawn from three historic populations, Sweden (1751-1919), France (1816-1919), and England and Wales (1841-1919), were analyzed using time series methods to assess whether conditions at midlife significantly influenced or "programmed" later life longevity. Results indicated a significant inverse association between mortality at ages 45-49, the average age range in which perimenopause occurred, and life expectancy at age 60 among females in all three countries. Study findings suggest a degree of plasticity associated with women's aging and, in particular, the age group correlated with perimenopause.

"Inflammaging" and Estradiol among Older U.S. Women: A Nationally Representative Longitudinal Study

Despite accumulating small-sample and clinical evidence on "inflammaging," no population-representative longitudinal studies have specifically examined women's late-life inflammation trends. While a range of studies indicates estradiol's immunomodulation role, evidence is contradictory on whether its effects are pro- or antiinflammatory among older women. Using longitudinal data from the first two waves of the National Social Life, Health and Aging Project-a national probability sample of older U.S. adults aged 57 to 85 years at baseline-this study began to fill these gaps. Findings suggested rather than being a lifelong process, older women's inflammaging may have a biological window that closes with senescence. Moreover, their endogenous estradiol plays a proinflammatory rather than immunoprotective role. Nor does this sex steroid modulate age effects on women's inflammation. More sex-specific basic research is needed on causal mechanisms underlying women's late-life inflammaging patterns.

Allostatic load and pain severity in older adults: Results from the English Longitudinal Study of Ageing

Pain is common in older adults, is frequently experienced as stressful, and is associated with increased morbidity and mortality. Stress regulatory systems are adaptive to challenge and change, allostasis, until demands exceed the adaptive capacity contributing to dysregulation, resulting in a high allostatic load. A high allostatic load is associated with increased risk of morbidity and mortality. Pain severity, based on the average intensity of frequent pain, was hypothesized to be positively associated with AL. Four formulations of AL were investigated. Cross-sectional data from Wave 4 (2008-2009) of the English Longitudinal Study of Aging (ELSA) were analyzed. Covariates in the model included age, sex, education, smoking status, alcohol consumption, activity level, depression and common comorbid health conditions. A total of 5341 individuals were included; mean age 65.3(±9.2) years, 55% female, 62.4% infrequent or no pain, 12.6% mild pain, 19.1% moderate pain, and 5.9% severe pain. Severe pain was associated with greater AL defined by all four formulations. The amount of variance explained by pain severity and the covariates was highest when allostatic load was defined by the high risk quartile (12.9%) and by the clinical value (11.7%). Findings indicate a positive relationship between pain severity and AL. Further investigation is needed to determine if there is a specific AL signature for pain that differs from other health conditions.

Nativity differences in allostatic load by age, sex, and Hispanic background from the Hispanic Community Health Study/Study of Latinos

Allostatic load (AL), an index of biological "wear and tear" on the body from cumulative exposure to stress, has been little studied in US Hispanics/Latinos. We investigated AL accumulation patterns by age, sex, and nativity in the Hispanic Community Health Study/Study of Latinos. We studied 15,830 Hispanic/Latinos of Mexican, Cuban, Dominican, Puerto Rican, Central and South American descent aged 18-74 years, 77% of whom were foreign-born. Consistent with the conceptualization of AL, we developed an index based upon 16 physiological markers that spanned the cardiometabolic, parasympathetic, and inflammatory systems. We computed mean adjusted AL scores using log-linear models across age-groups (18-44, 45-54, 55-74 years), by sex and nativity status. Among foreign-born individuals, differences in AL by duration of residence in the US (<10, ≥10 years) and age at migration (<24, ≥24 years) were also examined. In persons younger than 55 years old, after controlling for socioeconomic and behavioral factors, AL was highest among US-born individuals, intermediate in foreign-born Hispanics/Latinos with longer duration in the US (≥10 years), and lowest among those with shorter duration in the US (<10 years) (P <0.0001 for increasing trend). Similarly, AL increased among the foreign-born with earlier age at immigration. These trends were less pronounced among individuals ≥55 years of age. Similar patterns were observed across all Hispanic/Latino heritage groups (P for interaction=0.5). Our findings support both a "healthy immigrant" pattern and a loss of health advantage over time among US Hispanics/Latinos of diverse heritages.

Anomaly in the education-health gradient: Biomarker profiles among adults with subbaccalaureate attainment levels

This Short Communication builds on recent findings that documented an anomaly in the education–health gradient: adults who attended college but did not earn a BA (the subbaccalaureate group) reported an equal or higher level of health problems than adults with high school (HS) diploma. Our aim is to test whether this anomaly holds when we eliminate potential reporting differences, by examining biomarker levels in the subbaccalaureate vs HS groups.

Using the restricted 1999–2012 NHANES, we estimate models of biomarkers for cardiovascular and metabolic diseases as a function of educational attainment, including three subbaccalaureate levels: “some college”, vocational associate degree (AA), and academic AA.

The data show that adults with “some college” or vocational AA have no systematic advantage over HS graduates in most biomarker indices while academic AA is associated with a significantly better risk profile compared to HS. The findings indicate that the adults with some college and vocational AA degrees do not benefit from their college experience in terms of improved physiological risk profile.

This pattern underscores the need to understand and explain the anomalous health pattern that concerns 28% of American adults in the subbaccalaureate group among whom many reap little health payoffs to postsecondary schooling.

Physiological wear-and-tear and later subjective health in mid-life: Findings from the 1958 British birth cohort

OBJECTIVE

Our body adapts continuously to environmental challenges and stressful conditions. Allostatic load (AL) is a concept that aims to capture the overall physiological wear-and-tear of the body triggered by the repeated activation of compensatory physiological mechanisms as a response to chronic stress. Growing evidence has shown a link between AL and later health decline, morbidity and mortality. However, due to the global physiological effect captured by the AL concept, it is particularly pertinent to examine its association with subsequent health by taking a broad definition of the latter. We examined the association between AL at 44 years and general health as measured by a latent multidimensional measure of subjective health at 50 years integrating sleep patterns, physical and mental health.

METHODS

AL was constructed using 14 biomarkers representing four physiological systems on 7573 members of the 1958 British birth cohort. Health status was captured using self-reported information about subjective health and summarized using a principal component analysis including: seven dimensions of the SF-36 questionnaire of health-related quality of life, the sleep subscale of the Medical Outcomes Study characterizing quality of sleep patterns, and a malaise inventory score detecting depressive symptoms.

RESULTS

Higher AL score was gradually associated with worse subjective health, after taking into account classic confounders.

CONCLUSIONS

Using a physiological index to grasp how the environment can "get under the skin" leading to poor health is of great interest, permitting a better understanding of life course origins of disease and social gradients in health.

Sex differences in immune responses

Males and females differ in their immunological responses to foreign and self-antigens and show distinctions in innate and adaptive immune responses. Certain immunological sex differences are present throughout life, whereas others are only apparent after puberty and before reproductive senescence, suggesting that both genes and hormones are involved. Furthermore, early environmental exposures influence the microbiome and have sex-dependent effects on immune function. Importantly, these sex-based immunological differences contribute to variations in the incidence of autoimmune diseases and malignancies, susceptibility to infectious diseases and responses to vaccines in males and females. Here, we discuss these differences and emphasize that sex is a biological variable that should be considered in immunological studies.

Investigating the Burden of Chronic Pain: An Inflammatory and Metabolic Composite

Background. Chronic pain is associated with increased morbidity and mortality, predominated by cardiovascular disease and cancer. Investigating related risk factor measures may elucidate the biological burden of chronic pain. Objectives. We hypothesized that chronic pain severity would be positively associated with the risk factor composite. Methods. Data from 12,982 participants in the 6th Tromsø study were analyzed. Questionnaires included demographics, health behaviors, medical comorbidities, and chronic pain symptoms. The risk factor composite was comprised of body mass index, fibrinogen, C-reactive protein, and triglycerides. Chronic pain severity was characterized by frequency, intensity, time/duration, and total number of pain sites. Results. Individuals with chronic pain had a greater risk factor composite than individuals without chronic pain controlling for covariates and after excluding inflammation-related health conditions (p < 0.001). A significant "dose-response" relationship was demonstrated with pain severity (p < 0.001). In individuals with chronic pain, the risk factor composite varied by health behavior, exercise, lower levels and smoking, and higher levels. Discussion. The risk factor composite was higher in individuals with chronic pain, greater with increasing pain severity, and influenced by health behaviors. Conclusions. Identification of a biological composite sensitive to pain severity and adaptive/maladaptive behaviors would have significant clinical and research utility.

Trajectories of the healthy ageing phenotype among middle-aged and older Britons, 2004-2013

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Women had a wider distribution of the healthy ageing phenotype than men had.

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Women started at higher levels and then declined more steeply, leading to crossover in the trajectories of the healthy ageing phenotype.

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Social gradients in the healthy ageing phenotype were significant.

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Smoking and physical activity were strongly associated with the trajectories.

Objectives

Since the ageing population demands a response to ensure older people remain healthy and active, we studied the dynamics of a recently proposed healthy ageing phenotype. We drew the phenotype’s trajectories and tested whether their levels and rates of change are influenced by health behaviours, comorbidities and socioeconomic positions earlier in the life course.

Design and outcomes

The English Longitudinal Ageing Study, a prospective, nationally representative sample of people aged ≥50 years, measured a set of eight biomarkers which make up the outcome of the healthy ageing phenotype three times over nearly a decade (N₂₀₀₄ = 5009, N₂₀₀₈ = 5301, N₂₀₁₃ = 4455). A cluster of health behaviours, comorbidities and socioeconomic positions were also measured repeatedly. We assessed the phenotype’s distribution non-parametrically, then fitted linear mixed models to phenotypic change and further examined time interactions with gender and socioeconomic position. We ran additional analyses to test robustness.

Results

Women had a wider distribution of the healthy ageing phenotype than men had. The phenotype declined annually by −0.242 (95% confidence interval [CI]: −0.352, −0.131). However, there was considerable heterogeneity in the levels and rates of phenotypic change. Women started at higher levels, then declined more steeply by −0.293 (CI: −0.403, −0.183) annually, leading to crossover in the trajectories. Smoking and physical activity assessed on the Allied Dunbar scale were strongly associated with the trajectories.

Conclusion

Though marked by secular decline, the trajectories of the healthy ageing phenotype showed distinct socioeconomic gradients. The trajectories were also susceptible to variations in health behaviours, strengthening the case for serial interventions to attain healthy and active ageing.

Social relationships and physiological determinants of longevity across the human life span

Two decades of research indicate causal associations between social relationships and mortality, but important questions remain as to how social relationships affect health, when effects emerge, and how long they last. Drawing on data from four nationally representative longitudinal samples of the US population, we implemented an innovative life course design to assess the prospective association of both structural and functional dimensions of social relationships (social integration, social support, and social strain) with objectively measured biomarkers of physical health (C-reactive protein, systolic and diastolic blood pressure, waist circumference, and body mass index) within each life stage, including adolescence and young, middle, and late adulthood, and compare such associations across life stages. We found that a higher degree of social integration was associated with lower risk of physiological dysregulation in a dose-response manner in both early and later life. Conversely, lack of social connections was associated with vastly elevated risk in specific life stages. For example, social isolation increased the risk of inflammation by the same magnitude as physical inactivity in adolescence, and the effect of social isolation on hypertension exceeded that of clinical risk factors such as diabetes in old age. Analyses of multiple dimensions of social relationships within multiple samples across the life course produced consistent and robust associations with health. Physiological impacts of structural and functional dimensions of social relationships emerge uniquely in adolescence and midlife and persist into old age.

Inflammation: depression fans the flames and feasts on the heat

Depression and inflammation fuel one another. Inflammation plays a key role in depression's pathogenesis for a subset of depressed individuals; depression also primes larger cytokine responses to stressors and pathogens that do not appear to habituate. Accordingly, treatment decisions may be informed by attention to questions of how (pathways) and for whom (predispositions) these links exist, which are the focus of this article. When combined with predisposing factors (moderators such as childhood adversity and obesity), stressors and pathogens can lead to exaggerated or prolonged inflammatory responses. The resulting sickness behaviors (e.g., pain, disturbed sleep), depressive symptoms, and negative health behaviors (e.g., poor diet, a sedentary lifestyle) may act as mediating pathways that lead to further, unrestrained inflammation and depression. Depression, childhood adversity, stressors, and diet can all influence the gut microbiome and promote intestinal permeability, another pathway to enhanced inflammatory responses. Larger, more frequent, or more prolonged inflammatory responses could have negative mental and physical health consequences. In clinical practice, inflammation provides a guide to potential targets for symptom management by signaling responsiveness to certain therapeutic strategies. For example, a theme across research with cytokine antagonists, omega-3 fatty acids, celecoxib, and exercise is that anti-inflammatory interventions have a substantially greater impact on mood in individuals with heightened inflammation. Thus, when inflammation and depression co-occur, treating them in tandem may enhance recovery and reduce the risk of recurrence. The bidirectional links between depression, inflammation, and disease suggest that effective depression treatments could have a far-reaching impact on mood, inflammation, and health.

Sex Differences in Depression: Does Inflammation Play a Role?

Women become depressed more frequently than men, a consistent pattern across cultures. Inflammation plays a key role in initiating depression among a subset of individuals, and depression also has inflammatory consequences. Notably, women experience higher levels of inflammation and greater autoimmune disease risk compared to men. In the current review, we explore the bidirectional relationship between inflammation and depression and describe how this link may be particularly relevant for women. Compared to men, women may be more vulnerable to inflammation-induced mood and behavior changes. For example, transient elevations in inflammation prompt greater feelings of loneliness and social disconnection for women than for men, which can contribute to the onset of depression. Women also appear to be disproportionately affected by several factors that elevate inflammation, including prior depression, somatic symptomatology, interpersonal stressors, childhood adversity, obesity, and physical inactivity. Relationship distress and obesity, both of which elevate depression risk, are also more strongly tied to inflammation for women than for men. Taken together, these findings suggest that women's susceptibility to inflammation and its mood effects may contribute to sex differences in depression. Depression continues to be a leading cause of disability worldwide, with women experiencing greater risk than men. Due to the depression-inflammation connection, these patterns may promote additional health risks for women. Considering the impact of inflammation on women's mental health may foster a better understanding of sex differences in depression, as well as the selection of effective depression treatments.

Sex differences in the impact of the Mediterranean diet on systemic inflammation

BACKGROUND

Some intervention trials have reported a reduction in systemic inflammation with the Mediterranean diet (MedDiet) while others have observed no effect. Despite the fact that sex differences have been highlighted in the inflammatory regulation, it is still not known whether MedDiet exerts similar effects on systemic inflammation in men and women. The aim of this study was therefore to investigate sex differences in the effects of the MedDiet on high-sensitivity C-reactive protein (hs-CRP).

FINDINGS

Participants were 35 men and 27 premenopausal women (24-53 years) presenting a slightly deteriorated lipid profile. All foods were provided to participants during a 4-week isocaloric MedDiet. At baseline, women had higher hs-CRP concentrations than men (P = 0.03). No sex difference was observed in hs-CRP response to the MedDiet (P for sex-by-time interaction = 0.36), with both men and women experiencing no change (respectively P = 0.62 and P > 0.99). When subgroups were formed according to hs-CRP concentration before the MedDiet phase, men with elevated baseline values (≥2 mg/l) experienced a reduction in hs-CRP over time with the MedDiet (-26.5 %) while an increase was observed in men with lower baseline values (+96.6 %; P for group-by-time interaction = 0.02). This pattern of change was not observed in women.

CONCLUSIONS

Results from this controlled feeding study suggest that men and women have similar effects from the MedDiet on systemic inflammation. The individual's overall inflammatory status seems to influence these effects, but only in men.

TRIAL REGISTRATION

This clinical trial was registered at www.clinicaltrials.gov as NCT01293344 .

Association of allostatic load with brain structure and cognitive ability in later life

Allostatic load (AL) has been proposed as a general framework for understanding the cumulative effects of life stress on individuals. Despite growing interest in AL, limited research has been conducted on aging samples. We consider the association of AL (operationalized by a range of inflammatory, cardiovascular, and metabolic measures) with a range of brain volume measurements and cognitive ability in a large cohort sample of older adults (n = 658, mean age = 72.5 years, standard deviation = 0.7) using structural equation modeling. AL was significantly inversely associated with total brain volume (range of standardized β = -0.16 to -0.20) and white-matter volume (-0.35 to -0.36) and positively with hippocampal volume (0.10-0.15) but not gray-matter volume (0.04). AL was also significantly inversely associated with general cognitive ability (range β = -0.13 to -0.20), processing speed (-0.20 to -0.22), and knowledge (-0.18 to -0.20) but not memory or nonverbal reasoning. The associations of AL with cognitive abilities were not mediated by these brain volume measures. AL did not predict cognitive change from age 11 to approximately age 73. The findings suggest a link between AL and later life brain health and cognitive functioning.

Trends in education gradients of 'preventable' mortality: a test of fundamental cause theory

Fundamental cause theory explains persisting associations between socioeconomic status and mortality in terms of personal resources such as knowledge, money, power, prestige, and social connections, as well as disparate social contexts related to these resources. We review evidence concerning fundamental cause theory and test three central claims using the National Health Interview Survey Linked Mortality Files 1986-2004. We then examine cohort-based variation in the associations between a fundamental social cause of disease, educational attainment, and mortality rates from heart disease, other "preventable" causes of death, and less preventable causes of death. We further explore race/ethnic and gender variation in these associations. Overall, findings are consistent with nearly all features of fundamental cause theory. Results show, first, larger education gradients in mortality risk for causes of death that are under greater human control than for less preventable causes of death, and, second, that these gradients grew more rapidly across successive cohorts than gradients for less preventable causes. Results also show that relative sizes and cohort-based changes in the education gradients vary substantially by race/ethnicity and gender.

Social relationships and hypertension in late life: evidence from a nationally representative longitudinal study of older adults

OBJECTIVE

Social relationships are widely understood to be important for sustaining and improving health and longevity, but it remains unclear how different dimensions of social relationships operate through similar or distinct mechanisms to affect biophysiological markers of aging-related disease over time.

METHOD

This study utilized longitudinal data on a nationally representative sample of older adults from the National Social Life, Health, and Aging Project (2005-2011) to examine the prospective associations between social integration and social support and change in systolic blood pressure (SBP) and hypertension risk over time.

RESULTS

Although both social relationship dimensions have significant physiological impacts, their relative importance differs by outcome. Low social support was predictive of increase in SBP, whereas low social integration was predictive of increase in risk of hypertension.

DISCUSSION

The different roles of relationship characteristics in predicting change in physiological outcomes suggest specific biophysiological stress response and behavioral mechanisms that have important implications for both scientific understandings and effective prevention and control of a leading chronic condition in late life.

Association between inflammatory biomarkers and bone mineral density in a community-based cohort of men and women

OBJECTIVE

Based upon evidence in animal and in vitro studies, we tested the hypothesis that higher serum concentrations of the cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) and the inflammatory marker C-reactive protein (CRP) would be inversely associated with bone mineral density (BMD) in a community-based cohort of men and women, with the strongest associations among postmenopausal women not receiving menopause hormonal therapy (MHT).

METHODS

We ascertained fasting serum concentrations of IL-6, TNFα, and CRP and measured BMD at the femoral neck, trochanter, total femur, and spine (L2-L4) using dual x-ray absorptiometry in 2,915 members of the Framingham Offspring Study (1996-2001). We used multivariable linear regression to estimate the difference (β) in BMD at each bone site associated with a 1-unit increase in log-transformed serum concentrations of IL-6, TNFα, and CRP separately for men (n = 1,293), premenopausal women (n = 231), postmenopausal women receiving MHT (n = 498), and postmenopausal women not receiving MHT (n = 893).

RESULTS

Inflammatory biomarkers were not associated with BMD in men. Among premenopausal women, there were statistically significant, modest inverse associations between IL-6 and trochanter BMD (β = -0.030, P < 0.01) and between CRP and femoral neck (β = -0.015, P = 0.05) and trochanter BMD (β = -0.014, P = 0.04). TNFα was positively associated with spine BMD (β = 0.043, P = 0.01). In postmenopausal women receiving MHT, CRP was positively associated with femoral neck BMD (β = 0.011, P = 0.04). There were no associations among postmenopausal women not receiving MHT.

CONCLUSION

The lack of consistency in our results suggests that elevated circulating concentrations of inflammatory biomarkers may not be a risk factor for low BMD.

Allostatic load and health in the older population of England: a crossed-lagged analysis

OBJECTIVE

Allostatic load, a composite measure of accumulated physical wear and tear, has been proposed as an early sign of physiological dysregulation predictive of health problems, functional limitation, and disability. However, much previous research has been cross sectional and few studies consider repeated measures. We investigate the directionality of associations between allostatic load, self-rated health, and a measure of physical function (walking speed).

METHODS

The sample included men and women 60 and older who participated in Wave 2 (2004) and Wave 4 (2008) of the English Longitudinal Study of Ageing (n = 6132 in Wave 2). Allostatic load was measured with nine biomarkers using a multisystem summary approach. Self-rated health was measured using a global 5 point summary indicator. Time to walk 8 ft was used as a measure of function. We fitted and tested autoregressive cross-lagged models between the allostatic load measure, self-rated health, and walking speed in Waves 2 and 4. Models were adjusted for age, sex, educational level, and smoking status at Wave 2 and for time-varying indicators of marital status, wealth, physical activity, and social support.

RESULTS

Allostatic load predicted slower walking speed (standardized estimate = -0.08, 95% confidence interval [CI] = -0.10 to -0.05). Better self-rated health predicted faster walking speed (standardized estimate = 0.11, 95% CI = 0.08-0.13) as well as lower allostatic load (standardized estimate = -0.15, 95% CI = -0.22 to -0.09), whereas paths from allostatic load and walking speed to self-rated health were weaker (standardized estimates = -0.05 [95% CI = -0.07 to -0.02] and 0.06 [95% CI = 0.04-0.08]).

CONCLUSIONS

Allostatic load can be a useful risk indicator of subsequent poor health or function.

The influence of body mass index, age and sex on inflammatory disease risk in semi-captive Chimpanzees

Obesity and ageing are emerging issues in the management of captive primates, including Chimpanzees, Pan troglodytes. Studies on humans show that obesity and old age can independently increase the risk of inflammatory-associated diseases indicated by elevated levels of pro-inflammatory cells and proteins in the blood of older or obese compared to levels in younger or non-obese individuals. In humans, sex can influence the outcomes of these risks. Health management of these problems in chimpanzee populations requires an understanding of similarities and differences of factors influencing inflammatory disease risks in humans and in chimpanzees. We examined the relationship between age, sex and Body Mass Index (BMI) with hematological biomarkers of inflammatory disease risk established for humans which include the neutrophil to lymphocyte ratio (NLR), and neutrophil, white blood cell (WBC), platelet microparticle and platelet counts. We found that higher values of NLR, neutrophil count and platelet microparticle count were associated with higher BMI values and older age indicating increased inflammation risk in these groups; a similar pattern to humans. There was a strong sex by age interaction on inflammation risk, with older males more at risk than older females. In contrast to human studies, total WBC count was not influenced by BMI, but like humans, WBC and platelet counts were lower in older individuals compared to younger individuals. Our findings are similar to those of humans and suggest that further insight on managing chimpanzees can be gained from extensive studies of ageing and obesity in humans. We suggest that managing BMI should be an integral part of health management in captive chimpanzee populations in order to partially reduce the risk of diseases associated with inflammation. These results also highlight parallels in inflammation risk between humans and chimpanzees and have implications for understanding the evolution of inflammation related diseases in apes.

Is self-rated health a stable and predictive factor for allostatic load in early adulthood? Findings from the Nord Trøndelag Health Study (HUNT)

Self-rated health (SRH) is a widely used health indicator predicting morbidity and mortality in a wide range of populations. However, little is known about the stability and biological basis of SRH. The aim of this study was to map the stability of SRH from adolescence to early adulthood, and to examine the relationships between SRH and biological dysregulation, in terms of allostatic load (AL). The AL score comprises the eleven biomarkers systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), cholesterol, high-density lipoprotein cholesterol (HDL), triglycerides, waist-hip ratio (WHR), diabetes risk profile, glucose, C-reactive protein (CRP) and body mass index (BMI). Eleven years prospective data from the Nord-Trøndelag Health Study (HUNT), Norway, were utilised. Baseline data were gathered from 9141 adolescents (mean age 15.9 years) in the Young-HUNT I survey (1995-1997) and follow-up data were gathered from the adult HUNT3 survey (2006-2008). Altogether, 1906 respondents completed both questionnaires and clinical measurements in both studies. Cross-tables for SRH at baseline and follow-up showed that SRH remained unchanged in 57% of the respondents. Only 3% of the respondents changed their ratings by two steps or more on a four-level scale. Further, linear regression analyses adjusted for age and gender revealed that SRH in adolescence predicted AL in young adulthood. Similar patterns were found for most of the individual biomarkers. The consistency found in SRH from adolescence to young adulthood, and its association with AL across time, indicate that routines for dealing with SRH early in life may be a central strategy to prevent morbidity in the adult population.

Sex-specific association of RANTES gene -403 variant in Meniere's disease

Several studies have shown the correlation between RANTES gene and inflammatory disorders; the aim of the present study was to investigate the association between RANTES promoter gene polymorphism and Meniere's disease (MD) in an Iranian population. In this study patients with MD comprising definite MD (N = 56) and probable MD (N = 15) were selected according to diagnostic criteria of AAO-HNS. The control group (N = 101) were healthy normal subjects who did not have a history of ear disease and vertigo. PCR-RFLP for RANTES -403G>A has been performed. We found a protective role for RANTES -403A allele in male group in our population. None of the male patients with MD were carrier of allele A which was significantly different from the presence of allele A in the male control group (AA+GA vs. GG: p = 0.0004, OR 0.05, 95 % CI 0.001-0.39). This difference was not significant in female group. There was no significant association between RANTES gene polymorphism and the level of hearing loss. our results showed a sex-specific association between RANTES gene polymorphism and MD but more studies are necessary to further assess this association.

Early maternal age at first birth is associated with chronic diseases and poor physical performance in older age: cross-sectional analysis from the International Mobility in Aging Study

BACKGROUND

Early maternal age at first birth and elevated parity may have long-term consequences for the health of women as they age. Both are known risk factors for obstetrical complications with lifelong associated morbidities. They may also be related to diabetes and cardiovascular disease development.

METHODS

We examine the relationship between early maternal age at first birth, defined as ≤18 years of age, multiparity (>2 births), and poor physical performance (Short Physical Performance Battery≤8) in community samples of women between 65 and 74 years of age from Canada, Albania, Colombia, and Brazil (N=1040). Data were collected in 2012 to provide a baseline assessment for a longitudinal cohort called the International Mobility in Aging Study. We used logistic regression and general linear models to analyse the data.

RESULTS

Early maternal age at first birth is significantly associated with diabetes, chronic lung disease, high blood pressure, and poor physical performance in women at older ages. Parity was not independently associated with chronic conditions and physical performance in older age. After adjustment for study site, age, education, childhood economic adversity and lifetime births, women who gave birth at a young age had 1.75 (95% CI: 1.17-2.64) the odds of poor SPPB compared to women who gave birth>18 years of age. Adjustment for chronic diseases attenuated the association between early first birth and physical performance. Results were weaker in Colombia and Brazil, than Canada and Albania.

CONCLUSIONS

This study provides evidence that adolescent childbirth may increase the risk of developing chronic diseases and physical limitations in older age. Results likely reflect both the biological and social consequences of early childbearing and if the observed relationship is causal, it reinforces the importance of providing contraception and sex education to young women, as the consequences of early pregnancy may be life-long.

Social support, social strain and inflammation: evidence from a national longitudinal study of U.S. adults

Social relationships have long been held to have powerful effects on health and survival, but it remains unclear whether such associations differ by function and domain of relationships over time and what biophysiological mechanisms underlie these links. This study addressed these gaps by examining the longitudinal associations of persistent relationship quality across a ten year span with a major indicator of immune function. Specifically, we examined how perceived social support and social strain from relationships with family, friends, and spouse at a prior point in time are associated with subsequent risks of inflammation, as assessed by overall inflammation burden comprised of five markers (C-reactive protein, interleukin-6, fibrinogen, E-selectin, and intracellular adhesion molecule-1) in a national longitudinal study of 647 adults from the Midlife Development in the United States (1995-2009). Results from multivariate regression analysis show that (1) support from family, friends, and spouse modestly protected against risks of inflammation; (2) family, friend, and total social strain substantially increased risks of inflammation; and (3) the negative associations of social strain were stronger than the positive associations of social support with inflammation. The findings highlight the importance of enriched conceptualizations, measures, and longitudinal analyses of both social and biological stress processes to elucidate the complex pathways linking social relationships to health and illness.