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Despite myriad efforts among social scientists, epidemiologists, and clinicians to identify variables with strong linkages to mortality, few researchers have evaluated statistically the relative strength of a comprehensive set of predictors of survival. Here, we determine the strongest predictors of five-year mortality in four national, prospective studies of older adults. We analyze nationally representative surveys of older adults in four countries with similar levels of life expectancy: England (n = 6113, ages 52+), the US (n = 2023, ages 50+), Costa Rica (n = 2694, ages 60+), and Taiwan (n = 1032, ages 53+). Each survey includes a broad set of demographic, social, health, and biological variables that have been shown previously to predict mortality. We rank 57 predictors, 25 of which are available in all four countries, net of age and sex. We use the area under the receiver operating characteristic curve and assess robustness with additional discrimination measures. We demonstrate consistent findings across four countries with different cultural traditions, levels of economic development, and epidemiological transitions. Self-reported measures of instrumental activities of daily living limitations, mobility limitations, and overall self-assessed health are among the top predictors in all four samples. C-reactive protein, additional inflammatory markers, homocysteine, serum albumin, three performance assessments (gait speed, grip strength, and chair stands), and exercise frequency also discriminate well between decedents and survivors when these measures are available. We identify several promising candidates that could improve mortality prediction for both population-based and clinical populations. Better prognostic tools are likely to provide researchers with new insights into the behavioral and biological pathways that underlie social stratification in health and may allow physicians to have more informed discussions with patients about end-of-life treatment and priorities. [ABSTRACT FROM AUTHOR]

Telomere length has generated substantial interest as a potential predictor of aging-related diseases and mortality. Some studies have reported significant associations, but few have tested its ability to discriminate between decedents and survivors compared with a broad range of well-established predictors that include both biomarkers and commonly collected self-reported data. Our aim here was to quantify the prognostic value of leukocyte telomere length relative to age, sex, and 19 other variables for predicting five-year mortality among older persons in three countries. We used data from nationally representative surveys in Costa Rica (N = 923, aged 61+), Taiwan (N = 976, aged 54+), and the U.S. (N = 2672, aged 60+). Our study used a prospective cohort design with all-cause mortality during five years post-exam as the outcome. We fit Cox hazards models separately by country, and assessed the discriminatory ability of each predictor. Age was, by far, the single best predictor of all-cause mortality, whereas leukocyte telomere length was only somewhat better than random chance in terms of discriminating between decedents and survivors. After adjustment for age and sex, telomere length ranked between 15th and 17th (out of 20), and its incremental contribution was small; nine self-reported variables (e.g., mobility, global self-assessed health status, limitations with activities of daily living, smoking status), a cognitive assessment, and three biological markers (C-reactive protein, serum creatinine, and glycosylated hemoglobin) were more powerful predictors of mortality in all three countries. Results were similar for cause-specific models (i.e., mortality from cardiovascular disease, cancer, and all other causes combined). Leukocyte telomere length had a statistically discernible, but weak, association with mortality, but it did not predict survival as well as age or many other self-reported variables. Although telomere length may eventually help scientists understand aging, more powerful and more easily obtained tools are available for predicting survival. [ABSTRACT FROM AUTHOR]

Recent studies have found mixed results regarding the association between leukocyte telomere length (LTL)--thought to be a marker of cellular aging--and all-cause mortality. Some studies have reported a significant inverse relationship, but others have not, perhaps in part owing to insufficient power. We examine the relationship using data from a nationally representative sample of older Taiwanese (54+ in 2000), which is larger (n = 942) than most previous studies, and which includes comprehensive information on potential confounders including white blood cell distribution and inflammatory markers. Results from a Cox hazards model demonstrate a small, but significant, association between LTL and mortality that is independent of age, sex, and lifestyle factors. White blood cell distribution, especially the proportion of neutrophils, is an important predictor of LTL; however, the association between LTL and mortality changes little controlling for white blood cell distribution. In contrast, the association between LTL and mortality weakens considerably (by 48%) after adjustment for inflammatory markers and homocysteine. Our results suggest that the relationship between short telomeres and mortality is tied to inflammation and homocysteine. Longitudinal studies are needed to explore bidirectional influences resulting from the fact that inflammation leads to shorter leukocyte telomeres, which in turn results in senescence, which exacerbates inflammation. [ABSTRACT FROM AUTHOR]

The proliferation of biosocial surveys has increased the importance of weighing the costs and benefits of adding biomarker collection to population-based surveys. A crucial question is whether biomarkers offer incremental value beyond self-reported measures, which are easier to collect and impose less respondent burden. We use longitudinal data from a nationally representative sample of older Taiwanese (aged 54+ in 2000, examined in 2000 and 2006 with mortality follow-up through 2011) to address that question with respect to predicting all-cause mortality. A summary measure of biomarkers improves mortality prediction (as measured by the area under the receiver operating characteristic curve) compared with self-reports alone, but individual biomarkers perform better than the summary score. We find that incorporating change in biomarkers over a six-year period yields a small improvement in mortality prediction compared with one-time measurement. But, is the incremental value worth the costs? [ABSTRACT FROM AUTHOR]

Allostatic load theory implies a relationship between exposure to psychological stress and multi-system physiological dysregulation. We used data from population-based samples of men and women in Russia (Moscow; n = 1800; age, mean 68.6 years), Taiwan ( n = 1036; 65.6 years) and the United States (US; n = 1054; 58.0 years) -- which are likely to vary widely with respect to levels of stress exposure and biological markers -- to determine the magnitude of the association between perceived stress and physiological dysregulation. The measure of overall dysregulation was based on 15 markers including standard cardiovascular/metabolic risk factors as well as markers of inflammation and neuroendocrine activity. Subjective psychological stress was measured by the perceived stress scale. Only the Moscow sample demonstrated a positive association with overall dysregulation in both sexes. In the US, we found an association among women but not men. Among the Taiwanese, who report the lowest perceived stress, there was no association in women but an unexpected inverse relationship in men. The effects also varied across system-level subscores: the association with perceived stress was most consistent for standard cardiovascular/metabolic factors. Perceived stress was associated with inflammation and neuroendocrine activity in some samples. Although the evidence that perceived stress is the primary source of physiological dysregulation is generally modest, it was stronger in Russia where the level of perceived stress was particularly high. For Russia only, we had information about heart function based on a 24 h ambulatory electrocardiogram; perceived stress was consistently associated with heart rate dysregulation in Russian men and women. [ABSTRACT FROM AUTHOR]

Abstract: The Russian population continues to face political and economic challenges, has experienced poor general health and high mortality for decades, and has exhibited widening health disparities. The physiological factors underlying links between health and socioeconomic position in the Russian population are therefore an important topic to investigate. We used data from a population-based survey of Moscow residents aged 55 and older (n = 1495), fielded between December 2006 and June 2009, to address two questions. First, are social disparities evident across different clusters of biomarkers? Second, does biological risk mediate the link between socioeconomic status and health? Health outcomes included subscales for general health, physical function, and bodily pain. Socioeconomic status was represented by education and an index of material resources. Biological risk was measured by 20 biomarkers including cardiovascular, inflammatory, and neuroendocrine markers as well as heart rate parameters from 24-h ECG monitoring. For both sexes, the age-adjusted educational disparity in standard cardiovascular risk factors was substantial (men: standardized β = −0.16, 95% CI = −0.23 to −0.09; women: β = −0.25, CI = −0.32 to −0.18). Education differences in inflammation were also evident in both men (β = −0.17, CI = −0.25 to −0.09) and women (β = −0.09, CI = −0.17 to −0.01). Heart rate parameters differed by education only in men (β = −0.10, CI = −0.18 to −0.02). The associations between material resources and biological risk scores were generally weaker than those for education. Social disparities in neuroendocrine markers were negligible for men and women. In terms of mediating effects, biological risk accounted for more of the education gap in general health and physical function (19–36%) than in bodily pain (12–18%). Inclusion of inflammatory markers and heart rate parameters—which were important predictors of health outcomes—may explain how we accounted for more of the social disparities than previous studies. [Copyright &y& Elsevier]

Objectives: To compare the effects of relaxation practice and other exercise on a multisystem measure of physiologic dysregulation in a national sample of older Taiwanese. Design: The study was a cross-sectional survey. Settings/location: The study was conducted in Taiwan. Subjects: A population-based sample of 1036 adults aged 53 and older completed an in-home interview and in-hospital physical examination. The final model is based on 934 respondents with complete data. Outcome measures: The outcome measures were overall dysregulation, based on 26 biomarkers, and subscores for cardiovascular/metabolic risk factors and inflammatory markers. Results: After adjustment for age and sex, overall dysregulation is 0.35 of a standard deviation (SD) lower for practitioners of relaxation techniques compared with nonpractitioners. The effect of exercise is smaller: 0.19 SD difference between those who exercise regularly and those who do not exercise. Similar effects of relaxation practice and regular exercise were found on inflammation, but smaller effects for cardiovascular/metabolic risk factors. In the presence of controls for sociodemographic characteristics, medication use, and a wide range of self-reported and interviewer-assessed health indicators, the effect of relaxation practice is attenuated but remains sizable (-0.19 of a SD for overall dysregulation); regular exercise has a comparable effect (-0.16 of a SD). The effects are similar for the inflammation subscore, but not significant for cardiovascular/metabolic risk factors after adjusting for health status. Conclusions: The physiologic benefits of relaxation practice that have been demonstrated in small experimental studies are also evident in the general population of older Taiwanese who practice these techniques in everyday life. Relaxation practice is associated with lower levels of physiologic dysregulation, particularly with respect to inflammation. Among this sample of older adults, the effect appears to be at least as large as that for exercise. Older people with limited ability to engage in vigorous exercise may especially welcome such information. [ABSTRACT FROM AUTHOR]

Abstract: We evaluated the association between two aspects of social relationships and six inflammatory markers in Taiwan and the U.S. These two countries share similar levels of current life expectancy, but exhibit important differences in social structure. The data comprised population based samples from Taiwan (aged 53+; n =962) and the U.S. (aged 35–86; n =990) collected between 2003 and 2009. Circulating levels of interleukin-6 (IL-6), C-reactive protein (CRP), fibrinogen, and soluble forms of intercellular adhesion molecule 1, E-selectin, and IL-6 receptor (sIL-6R) were measured in fasting blood samples. A social integration score was based on marital status, contact with family and friends, church attendance, and other social participation. A perceived social support index was based on questions regarding the availability of care and support from family and friends. Linear regression models tested the association between these two measures and each inflammatory marker controlling for sociodemographic characteristics, obesity, medication use, and baseline health status. After adjusting for potential confounders, social integration had a significant but weak inverse association with CRP in Taiwan. Perceived social support was significant in two of 12 models, and the coefficient was positive (i.e., higher support was associated with higher CRP and sIL-6R in the U.S.). We found no evidence that the coefficients for social relationship measures varied by sex or age. Our results yielded limited evidence of a weak association between two dimensions of social relationships and six inflammatory markers in Taiwan and the U.S. Given that the literature suggests a strong link between social relationships and mortality, and that inflammation plays an important role in the leading causes of death, we had expected to find consistent and moderately strong associations between social relationships and inflammatory markers. The small effect sizes and lack of robustness across markers were surprising. [Copyright &y& Elsevier]

Purpose: Short and long sleep duration and sleep quality are associated with health including all-cause mortality, cardiovascular disease, diabetes, and obesity. Inflammation may play a role in mediating these associations. Methods: We examined associations between inflammation and self-reported sleep characteristics in 1020 respondents of the 2000 and 2006 Social Environment and Biomarkers of Aging Study, a nationally representative survey of Taiwanese adults ages 53 and over. Regression models were used to estimate cross-sectional relationships between inflammation (interleukin-6, C-reactive protein, fibrinogen, e-selectin, soluble intercellular adhesion molecule-1, albumin, and white blood cell count) and a modified Pittsburgh Sleep Quality Index, index subcomponents, and self-reported sleep duration. Change in inflammatory markers between 2000 and 2006 was also used to predict long or short sleep duration in 2006. Results: Inflammation was not related to the overall index of sleep quality. However, longer sleep (>8 hr) was associated with higher levels of inflammation. These associations remained after adjustment for waist circumference, self-reported health decline, diabetes, arthritis/rheumatism, heart disease, and depressive symptoms. Increases in inflammation between 2000 and 2006 were associated with long but not short sleep duration in 2006 for several markers. Conclusions: Long sleep duration may be a marker of underlying inflammatory illness in older populations. Future studies should explore whether inflammation explains observed relationships between long sleep and mortality. [ABSTRACT FROM AUTHOR]

Identifying how biological parameters change with age can provide insights into the physiological determinants of disease and, ultimately, death. Most prior studies of age-related change in biomarkers are based on cross-sectional data, small or selective samples, or a limited number of biomarkers. We use data from a nationally representative longitudinal sample of 639 Taiwanese aged 54 and older in 2000 to assess changes over a six-year period in a wide range of biomarkers. Markers that increased most with age were glycoslyated hemoglobin, interleukin-6, and norepinephrine. Markers that decreased most with age were diastolic blood pressure and creatinine clearance. For example, glycoslyated hemoglobin increased by 8% to 13%, depending on sex and age at baseline, over this six-year period. Several standard clinical risk factors exhibited little evidence of age-related change. Further research is needed to determine whether the observed variation between individuals in biomarker changes represents differences in underlying physiological function that are predictive of future health and survival. [ABSTRACT FROM PUBLISHER]

Abstract: Despite a myriad of studies examining the relationship between socioeconomic status and health outcomes, few have assessed the extent to which biological markers of chronic disease account for social disparities in health. Studies that have examined this issue have generally been based on surveys in wealthy countries that include a small set of clinical markers of cardiovascular disease. The availability of recent data from nationally representative surveys of older adults in Costa Rica and Taiwan that collected a rich set of biomarkers comparable to those in a recent US survey permits us to explore these associations across diverse populations. Similar regression models were estimated on three data sets – the Social Environment and Biomarkers of Aging Study in Taiwan, the Costa Rican Study on Longevity and Healthy Aging, and the Health and Retirement Study in the USA – in order to assess (1) the strength of the associations between educational attainment and a broad range of biomarkers; and (2) the extent to which these biomarkers account for the relationships between education and two measures of health status (self-rated health, functional limitations) in older populations. The estimates suggest non-systematic and weak associations between education and high risk biomarker values in Taiwan and Costa Rica, in contrast to generally negative and significant associations in the US, especially among women. The results also reveal negligible or modest contributions of the biomarkers to educational disparities in the health outcomes. The findings are generally consistent with previous research suggesting stronger associations between socioeconomic status and health in wealthy countries than in middle-income countries and may reflect higher levels of social stratification in the US. With access to an increasing number of longitudinal biosocial surveys, researchers may be better able to distinguish true variations in the relationship between socioeconomic status and health across different settings from methodological differences. [Copyright &y& Elsevier]

The inclusion of biomarkers in social surveys such as the Panel Study of Income Dynamics (PSID) has the potential to answer many elusive questions in social science and public health, including the much-studied relationship between socioeconomic status and health. This article reviews the potential inclusion of biomarkers of cardiovascular and metabolic risk in the PSID. We first discuss the considerable analytical benefits of adding these biomarkers to the PSID, including the exploration of life course hypotheses and the potential to test causal relationships between the social environment and biological systems. Next, we review evidence on the reliability of self-reports of cardiovascular and metabolic risk factors, concluding that the potential bias from relying on self-reports may be substantial. Based on evidence of biological importance as well as practical considerations of ease of in-home collection, our first tier of recommended biomarkers includes measured height, weight, waist and hip circumference, diastolic and systolic blood pressure, resting heart rate, total and high-density lipoprotein (HDL) cholesterol, glycosylated hemoglobin (HbA1c), C-reactive protein (CRP), and cystatin C. Additional markers of secondary priority are also discussed. [ABSTRACT FROM AUTHOR]

Background. Few studies focus on "preclinical" warning signs associated with mortality. In this article, we investigate associations between all-cause mortality and two clusters of biological risk factors: (i) standard clinical measures related to cardiovascular disease and metabolic function; and (ii) nonclinical measures pertaining to hypothalamic-pituitary-adrenal axis activity, sympathetic nervous system activity, and inflammatory response. Methods. Data come from the 2000 Social Environment and Biomarkers of Aging Stud,. a national sample of Taiwanese persons aged 54 years or older; 1497 persons were interviewed in their homes, and 1023 participated in a hospital examination. The analysis is based on 927 respondents with complete information. Logistic regression models describe the association between biomarkers and the 3-year probability of dying. Results. Although both groups of biomarkers are significantly associated with mortality, the model with neuroendocrine and immune biomarkers has better explanatory and discriminatory power than the one with clinical measures. The association between these nonclinical measures and mortality remains strong after adjustment for the clinical markers, suggesting that the physiological effects of the nonclinical biomarkers are broader than those captured by the cardiovascular and metabolic system measures included here. Conclusions. Nonclinical markers are likely to provide warning signs of deteriorating health and function beyond what can be learned from conventional markers. Our findings are consistent with those of recent studies that (i) demonstrate the importance of neuroendocrine and immune system markers for survival, and (ii) indicate that standard clinical variables are less predictive of mortality in older than in younger populations. [ABSTRACT FROM AUTHOR]

Abstract: We investigate whether a multi-system measure of physiological dysregulation based on 16 biological measures is associated with deterioration in physical and mental health over a 3-year period. The data come from a national survey of persons 54 and older in Taiwan that collected standard clinical markers related to cardiovascular and metabolic function and “non-clinical” measures pertaining to the immune, neuroendocrine and sympathetic nervous systems. The dysregulation score counts the number of biomarkers for which values are in the lowest or highest decile. Statistical models examine whether dysregulation predicts four health outcomes (survival, physical functioning, cognitive functioning and depressive symptoms), in the presence of extensive controls for baseline health. The estimates reveal significant associations between dysregulation and health for each outcome, although there is variability across outcomes. The associations are often attenuated in the presence of health controls, underscoring the importance of longitudinal analysis. This study extends previous research on the health consequences of physiological dysregulation by considering a broader range of outcomes and biomarkers in a non-Western population-based sample. Our analysis suggests that such dysregulation provides early warning signs of a broad range of comorbidities. [Copyright &y& Elsevier]

Objectives: To test the relation between socioeconomic status (SES) and biomarkers of chronic stress, including basal cortisol, and to test whether these biomarkers account for the relation between SES and health outcomes. Design: Cross sectional study using data from the 2000 social and environmental biomarkers of aging study (SEBAS). Setting: Taiwan. Participants: Nationally representative sample of 972 men and women aged 54 and older. Main outcome measures: Highest risk quartiles for 13 biomarkers representing functioning of the neuroendocrine system, immune/inflammatory systems, and the cardiovascular system: cortisol, adrenaline (epinephrine), noradrenaline (norepinephrine), serum dihydroepiandrosterone sulphate (DHEA-S), insulin-like growth factor 1 (IGF1), interleukin 6 (IL6), albumin, systolic blood pressure, diastolic blood pressure, waist-hip ratio, total cholesterol-HDL ratio, HDL cholesterol, and glycosylated haemoglobin; self reported health status (1–5) and self reported mobility difficulties (0–6). Results: Lower SES men have greater odds of falling into the highest risk quartile for only 2 of 13 biomarkers, and show a lower risk for 3 of the 13 biomarkers, with no association between SES and cortisol. Lower SES women have a higher risk for many of the cardiovascular risk factors, but a lower risk for increased basal readings of adrenaline, noradrenaline, and cortisol. Inclusion of all 13 biological markers does not explain the relation between SES and health outcomes in the sample. Conclusions: These data do not support the hypothesis that chronic stress, via sustained activation of stress related autonomic and neuroendocrine responses, is an important mediator in the relation between SES and health outcomes. Most notably, lower SES is not associated with higher basal levels of cortisol in either men or women. These results place an increased burden of proof on researchers who assert that psychosocial stress is an important pathway linking SES and health. [ABSTRACT FROM AUTHOR]

Researchers have had a longstanding interest in understanding the determinants of mortality. This article examines the impact of a broad array of biological markers, together with self-reports of physical and mental health status, on the probability of dying for older adults. The estimates are derived from logistic regression models based on data from a national survey in Taiwan. The analysis confirms previous studies demonstrating the effects of clinical measures related to metabolic syndrome on mortality and identifies detrimental effects of neuroendocrine and immune-system markers. The results reveal that biomarkers provide independent explanatory power in the presence of self-reported health measures. The associations between biomarkers and mortality found here provide new avenues for projecting future mortality and elucidating differences in longevity across populations. [ABSTRACT FROM AUTHOR]

We use a population-based representative sample of older Taiwanese to investigate links between respondents' perceived levels of stress and a broad set of biological measures. These biomarkers were collected at a single time (2000) and reflect sympathetic nervous system (SNS)-activity, hypothalamo-pituitary-adrenal (HPA)-activity, immune function, cardiovascular function, and metabolic pathways. We model the relationship between perceived stress and (1) extreme values for each of 16 individual biological indicators; and (2) a measure of cumulative physiological dysregulation based on the full set of biomarkers. We consider two measures of perceived stress, one derived from the 2000 interview and the second based on data from three interviews (1996–2000). Age and sex-adjusted models reveal significant associations between measures of perceived stress and extreme values of cortisol, triglycerides, interleukin-6 (IL-6), dehydroepiandrosterone sulphate (DHEAS) and fasting glucose. Examined individually, numerous biomarkers, including those pertaining to blood pressure and obesity, are not significantly related to perceived stress. Jointly, however, the measure of cumulative physiological dysregulation is associated with both the level of perceived stress at a given time and to a longitudinal measure of perceived stress. Some results suggest that the relationship between level of perceived stress and physiological response is stronger for women than men. [ABSTRACT FROM AUTHOR]

Abstract: The theory of allostatic load [McEwen, B.S., Stellar, E., 1993. Stress and the individual: mechanisms leading to disease. Arch. Intern. Med. 153, 2093–2101] describes how the cumulative experience of emotional challenges and stressful events over the life course may take a significant physiological toll on multiple interrelated systems of the body. Various summary measures of these effects have been proposed in the literature, but few studies focus on systematically evaluating them. We use data from a population-based sample of older Taiwanese to compare the explanatory power and cross-sectional predictive performance of several measures of allostatic load for diverse health outcomes. We find that choices regarding which biomarkers to include in a summary measure and how the measure is formed have modest effects across the basic prediction models we evaluate. Our findings suggest that count-based summary measures incorporating risk at both high and low tails and measures that preserve the continuous properties of the biological variables are strategies that may yield stronger predictions of a wider array of health outcomes than other measures. These fundamental insights are useful for researchers in search of empirical formulations of allostatic load and for those who are focused on the development of improved measurement strategies. [Copyright &y& Elsevier]

We investigate how biological markers of individual responses to stressful experiences are associated with profiles of physical and mental functioning in a national sample of middle-aged and elderly Taiwanese. Data come from a population-based sample of middle-aged and elderly Taiwanese in 2000. The data combine rich biological measures with self-reported information on physical and mental health. Grade of membership methods are used to summarize functional status, and multinomial logit models provide information on the association between biological measures and function. The analysis identifies significant associations between biomarkers of stressful experience and profiles of physical and mental functioning. The estimates reveal the potential importance for health of both low and high values of biological parameters. The findings point to directions for future research regarding development of aggregate measures of cumulative dysregulation across multiple physiological systems. [ABSTRACT FROM AUTHOR]

Purpose: In light of widespread interest in the prognostic value of biomarkers, we apply three discrimination measures to evaluate the incremental value of biomarkers--beyond self-reported measures--for predicting all-cause mortality. We assess whether all three measures--area under the receiver-operating characteristic curve, continuous net reclassification improvement, and integrated discrimination improvement--lead to the same conclusions.Methods: We use longitudinal data from a nationally representative sample of older Taiwanese (n = 639, aged 54 or older in 2000, examined in 2000 and 2006, with mortality follow-up through 2011). We estimate age-specific mortality using a Gompertz hazard model.Results: The broad conclusions are consistent across the three discrimination measures and support the inclusion of biomarkers, particularly inflammatory markers, in household surveys. Although the rank ordering of individual biomarkers varies across discrimination measures, the following is true for all three: interleukin-6 is the strongest predictor, the other three inflammatory markers make the top 10, and homocysteine ranks second or third.Conclusions: The consistency of most of our findings across metrics should provide comfort to researchers using discrimination measures to evaluate the prognostic value of biomarkers. However, because the degree of consistency varies with the level of detail inherent in the research question, we recommend that researchers confirm results with multiple discrimination measures. [ABSTRACT FROM AUTHOR]

There are large socioeconomic disparities in adult mortality in Russia, although the biological mechanisms are not well understood. With data from the study of Stress, Aging, and Health in Russia (SAHR), we use Gompertz hazard models to assess the relationship between educational attainment and mortality among older adults in Moscow and to evaluate biomarkers associated with inflammation, neuroendocrine function, heart rate variability, and clinical cardiovascular and metabolic risk as potential mediators of that relationship. We do this by assessing the extent to which the addition of biomarker variables into hazard models of mortality attenuates the association between educational attainment and mortality. We find that an additional year of education is associated with about 5% lower risk of age-specific all-cause and cardiovascular mortality. Inflammation biomarkers are best able to account for this relationship, explaining 25% of the education-all-cause mortality association, and 35% of the education-cardiovascular mortality association. Clinical markers perform next best, accounting for 13% and 23% of the relationship between education and all-cause and cardiovascular mortality, respectively. Although heart rate biomarkers are strongly associated with subsequent mortality, they explain very little of the education-mortality link. Neuroendocrine biomarkers fail to account for any portion of the link. These findings suggest that inflammation may be important for understanding mortality disparities by socioeconomic status. [ABSTRACT FROM AUTHOR]

The Social Environment and Biomarkers of Aging Study (SEBAS) is a nationally representative longitudinal survey of Taiwanese middle-aged and older adults. It adds the collection of biomarkers and performance assessments to the Taiwan Longitudinal Study of Aging (TLSA), a nationally representative study of adults aged 60 and over, including the institutionalized population. The TLSA began in 1989, with follow-ups approximately every 3 years; younger refresher cohorts were added in 1996 and 2003. The first wave of SEBAS, based on a sub-sample of respondents from the 1999 TLSA, was conducted in 2000. A total of 1023 respondents completed both a face-to-face home interview and, several weeks later, a hospital-based physical examination. In addition to a 12-h (7 pm-7 am) urine specimen collected the night before and a fasting blood specimen collected during the examination, trained staff measured blood pressure, height, weight and waist and hip circumferences. A second wave of SEBAS was conducted in 2006 using a similar protocol to SEBAS 2000, but with the addition of performance assessments conducted by the interviewers at the end of the home interview. Both waves of SEBAS also included measures of health status (physical, emotional, cognitive), health behaviours, social relationships and exposure to stressors. The SEBAS data, which are publicly available at [http://www.icpsr.umich.edu/icpsrweb/NACDA/studies/3792/version/5], allow researchers to explore the relationships among life challenges, the social environment and health and to examine the antecedents, correlates and consequences of change in biological measures and health. [ABSTRACT FROM AUTHOR]

To compare the association between subjective ladder ranking and health measures with the association between objective indices and health measures in older Taiwanese men and women.Cross-sectional study.A population-representative sample of elderly and nearly elderly men and women in Taiwan.The study included 991 participants from the Social Environment and Biomarkers of Aging Study in Taiwan.The information collected included demographic characteristics; subjective ladder score of SES; objective measures of SES, including education, income, and occupation; health behaviors; health-related variables such as self-rated health, basic activity of daily living difficulties, instrumental activity of daily living (IADL) difficulties, and physical activity difficulties; and depression score.Low ladder score was associated with poorer self-rated health and more reported IADL and physical activity difficulties, even after adjustment for objective measures of SES and other covariates. The multiply adjusted odds ratio for a one-quartile difference in ladder score and worse self-rated health was 1.19 (95% confidence interval=1.06–1.33). The associations between subjective ladder ranking and health status were generally stronger in those who had 6 years or less of education than in those who received more education.A simple subjective assessment of one's ranking on the social hierarchy was associated with self-rated health and physical functional status in an older ethnic Chinese population. The associations were independent of the effects of traditional objective measures of SES, such as education, income, and occupation. [ABSTRACT FROM AUTHOR]

Quantification of biological aging is of interest in gerontology as a means to surveil aging rates in the population and to evaluate the effects of interventions to increase healthy life span. Analysis of proposed methods to quantify biological aging has focused on samples of midlife or mixed-age adults in the West. Research is needed to test whether quantifications of biological aging can differentiate aging rates among older adults and if quantifications of biological aging developed in Western samples can differentiate aging rates in non-Western populations. We conducted analysis of Klemera-Doubal method (KDM) Biological Age and homeostatic dysregulation measures of biological aging developed in the U.S. NHANES and tested in a sample of older Taiwanese adults in the Social Environment and Biomarkers of Aging Study. We conducted analysis of physical and cognitive function and mortality, comparing quantifications of biological aging to a biomarker index based on norms within our analysis sample and to participants' ratings of their own health. Results showed that quantifications of biological aging (a) predicted differences in physical and cognitive function and in mortality risk among Taiwanese older adults and (b) performed as well as a traditional biomarker index and participant self-rated health for prediction of these outcomes. [ABSTRACT FROM AUTHOR]