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1.  TO WHAT EXTENT DO BIOMARKERS ACCOUNT FOR THE LARGE SOCIAL DISPARITIES IN HEALTH IN MOSCOW? 
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-hour 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.
doi:10.1016/j.socscimed.2012.11.022
PMCID: PMC3544298  PMID: 23228966
Russia; biological markers; socioeconomic status; education; health
2.  APOLIPOPROTEIN E AND MEASURED PHYSICAL AND PULMONARY FUNCTION IN OLDER TAIWANESE ADULTS 
The apolipoprotein E (ApoE) gene, which has three common alleles (ε2, ε3, and ε4), has been linked to a number of health outcomes and longevity. The ε2 allele has been reported to have neuroprotective effects, whereas the ε4 allele has been shown to be a risk factor for cardiovascular disease and Alzheimer’s disease in various populations. The relationships between ApoE and mortality and ApoE and physical function, however, are not clearcut. We used the Social Environment and Biomarkers of Aging Study (SEBAS) to examine the relationship between ApoE polymorphisms and physical and pulmonary function in approximately 1,000 Taiwanese adults ages 53 and older in 2006. In the 2006 wave, measures of physical function included self-reported difficulties with respect to activities of daily living (ADLs) and other physical function indicators, as well as performance-based measures of grip strength (kg), 3m walking speed (m/sec), and chair stand speed (stand/sec). Peak expiratory flow (PEF; L/min) rate was also examined as an indicator of pulmonary function. We used logistic regression models to determine the association between ApoE and inability to complete each of the tests of physical and pulmonary function. This revealed no significant association between ApoE carrier status and any of the indicators of function. Among participants able to complete a given task, we next used linear regression models to examine self-reported limitations with ADLs and performance on the given test by ApoE carrier status. Similarly, there were no significant relationships between ApoE carrier status and the measures of function. Our estimates provide further confirmation that the ApoE gene may not be a risk factor for functional decline among older Taiwanese adults.
doi:10.1080/19485565.2013.778703
PMCID: PMC3704952  PMID: 23701536
3.  Do Adults Adjust their Socioeconomic Status Identity in Later Life?* 
Ageing and society  2011;32(4):616-633.
Previous research shows that socioeconomic status (SES) identity, also referred to as perceived or subjective social status, is shaped by objective measures of status, socio-cultural influences and psychological attributes and predicts current and future well-being. Prior studies, however, have not examined whether older adults reassess their SES identity over time. In this study, we use two assessments of subjective social status measured six years apart in a sample of older Taiwanese adults to: 1) determine the degree to which respondents adjust their perceptions of social rank; and 2) identify the characteristics of individuals who are most likely to revise their assessments. We find that many older Taiwanese adults reassess their SES identity, but most respondents show small to moderate levels of change. Females, more highly educated respondents, and those who have a positive economic outlook tend to revise their subjective social status upward relative to their respective counterparts; those who become widowed during the period adjust their rankings downward compared with those who do not become widowed. These findings suggest that SES identity may be dynamic, highlighting the importance of collecting information on socioeconomic status identity at multiple points in the life course.
doi:10.1017/S0144686X11000432
PMCID: PMC3745029  PMID: 23956477
subjective social status; older adults; Taiwan
4.  Relaxation Practice and Physiologic Regulation in a National Sample of Older Taiwanese 
Abstract
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.
doi:10.1089/acm.2010.0598
PMCID: PMC3405452  PMID: 22775201
5.  Social Relationships and Inflammatory Markers: An Analysis of Taiwan and the U.S. 
Social science & medicine (1982)  2012;74(12):1891-1899.
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.
doi:10.1016/j.socscimed.2012.02.020
PMCID: PMC3348237  PMID: 22483707
Social relationships; social support; inflammation markers; Taiwan; USA
6.  Apolipoprotein E, biomarkers, and mortality in Taiwanese older adults 
Atherosclerosis  2011;219(1):349-354.
Polymorphisms of the apolipoprotein E gene (ApoE) have been associated with health and longevity. Numerous studies have linked ApoE to health outcomes including cardiovascular disease and mortality, but far fewer studies have examined the relationship of ApoE to other biological markers of health. This study investigates the relationship between ApoE and mortality, as well as ApoE and a set of biomarkers related to cardiovascular and immune function, in a population-based sample of Taiwanese adults ages 54+. ApoE ε2 carriers were less likely to have at-risk levels of high-density lipoprotein (HDL-C) and total cholesterol (total-C) than non-carriers (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.25-0.83 and OR 0.45, 95% CI 0.29-0.71, respectively). ApoE ε4 carriers were less likely to have elevated levels of C-reactive protein (CRP) than non-carriers (OR 0.62, 95% CI 0.39-0.96). ApoE genotype was not, however, associated with mortality after 8-years of follow-up. Our findings confirm the association between ApoE ε2 and cholesterol levels, suggesting a potential protective effect of ApoE ε2 on blood lipids. They also contribute to reports on the relationship between ApoE ε4 carrier status and lower CRP levels.
doi:10.1016/j.atherosclerosis.2011.07.100
PMCID: PMC3225086  PMID: 21840004
Apolipoprotein E; Cholesterol; C-reactive protein; Mortality
7.  Age-Related Changes in Biomarkers: Longitudinal Data from a Population-Based Sample 
Research on aging  2011;33(3):312-326.
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 8-13%, on average, 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.
doi:10.1177/0164027511399105
PMCID: PMC3109912  PMID: 21666867
8.  Demographic and Socioeconomic Status Differences in Perceptions of Difficulty With Mobility in Late Life 
Objectives.
This study assesses whether socioeconomic and demographic differences in reported mobility limitations are attributable to differential perceptions of mobility difficulty that result in the differential use of response categories.
Methods.
Data come from the Social Environment and Biomarkers of Aging Study and its parent study, the Taiwan Longitudinal Study of Aging. Ordered probit models with person-specific cut-points are used to test whether, after controlling for underlying mobility using objective performance measures, cut-points for reporting mobility limitations vary across groups defined by demographic and socioeconomic characteristics.
Results.
Age is the only characteristic that is consistently associated with the location of the cut-points for reporting mobility difficulty: At the same level of underlying mobility difficulty, older adults are more likely than younger adults are to report difficulty with all tasks except short walks. Other variables showed differences but only for one specific activity, for example, urban residents are more likely to report difficulty running than are rural residents with the same underlying level of mobility function.
Discussion.
For most mobility activities, there are no systematic differences in the perception of difficulty by individual characteristics. Thus, for older Taiwanese adults, differences in mobility limitations associated with socioeconomic status are more likely to reflect underlying differences in function than differences in how these groups report the same capacity. The usual loss of mobility with age, however, reflects both a decrease in capacity and a lowering of the threshold for reporting difficulty.
doi:10.1093/geronb/gbq087
PMCID: PMC3107021  PMID: 21098041
Cut-point shifts; Mobility difficulty; Older adults; Taiwan
9.  Biomarkers in population-based studies 
doi:10.1503/cmaj.101429
PMCID: PMC3001497  PMID: 20974717
10.  A new method for estimating smoking-attributable mortality in high-income countries 
Background Cigarette smoking is responsible for a massive loss of life in both developed and developing countries. This article develops an alternative to the Peto–Lopez method for estimating the number or fraction of smoking-attributable deaths in high-income countries.
Methods We use lung cancer death rates as an indicator of the damage caused by smoking. Using administrative data for the population aged ≥50 years from 20 high-income countries in the period from 1950 to 2006, we estimate a negative binomial regression model that predicts mortality from causes other than lung cancer as a function of lung cancer mortality and other variables. Using this regression model, we estimate smoking-attributable deaths based on the difference between observed death rates from lung cancer and expected rates among non-smokers.
Results Combining the estimated number of excess deaths from lung cancer with those from other causes, we find that among males in 1955 the smoking-attributable fraction was highest in Finland (18%); among women, no country exceeded 1%. By 2003, Hungary had the highest fraction of smoking-attributable deaths among males (32%), whereas the USA held that position among women (24%). Our estimates are remarkably similar to those produced by the Peto–Lopez method, a result that supports the validity of each approach.
Conclusions We provide a simple and straightforward method for estimating the proportion of deaths attributable to smoking in high-income countries. Our results demonstrate that smoking has played a central role in levels, trends and international differences in mortality over the past half century.
doi:10.1093/ije/dyp360
PMCID: PMC2915474  PMID: 20032265
Smoking, mortality; smoking/mortality; high-income populations; lung neoplasms; cause of death
11.  The Serotonin Transporter Polymorphism (5-HTTLPR): Allelic Variation and Links with Depressive Symptoms 
Depression and anxiety  2010;27(3):260-269.
Background
We compare the genotype distribution for the serotonin transporter polymorphism (5-HTTLPR) in a sample of older Taiwanese adults with samples of various racial and ethnic groups collected in other studies. We also explore interactions among sex, stressors, and 5-HTTLPR genotype on depressive symptoms in our sample.
Methods
Using a nationally-representative sample of 984 Taiwanese aged 53 and older, we model depressive symptoms as a function of 5-HTTLPR genotype and two classes of stressors: lifetime trauma and recent major life events. We test two- and three-way interactions among stressors, 5 HTTLPR, and sex.
Results
This sample exhibits higher frequency of S/S and lower frequency of L/L genotype than Western samples, but the distribution is comparable to those in East Asian populations. Nearly 9% carry an allele (XL) that has rarely been reported in the literature. Although the gene-environment (GxE) interaction with recent major life events is not significant, our results suggest that trauma has a worse effect on depressive symptoms for those with S/S or S/L genotype than for those who do not carry the S allele (p<0.05). We find no evidence that this GxE interaction varies by sex.
Conclusions
Previous studies of this GxE interaction have been inconclusive, perhaps because interactions between genotype and stressful events are more prominent under extreme stressors. Our findings underscore the need to move beyond a bi-allelic parameterization of the 5-HTTLPR polymorphism and raise questions about why East Asian populations exhibit low rates of depression despite a high frequency of the S allele.
doi:10.1002/da.20660
PMCID: PMC2841212  PMID: 20196101
SLC6A4 protein; depressive disorder; life change events; stressful events; Taiwan
12.  Sex differences in the relationship between DHEAS and health 
Experimental gerontology  2007;42(10):979-987.
Dehydroepiandrosterone (DHEA) and its sulfate form (DHEAS) have been the focus of considerable publicity because of their demonstrated associations with a broad range of health outcomes. Yet, knowledge about the effects of endogenous DHEA(S) on health in humans is limited and often inconclusive, largely because few of the studies have been based on prospective surveys of population-representative samples. This analysis uses a national longitudinal survey in Taiwan to investigate whether DHEAS is associated with subsequent changes (2000–2003) in functional limitations, cognitive impairment, depressive symptoms, and global self-rated health. Multivariate regression models based on this older Taiwanese sample show that among men, lower levels of DHEAS are related to declines in mobility and self-assessed health status and increases in depressive symptoms, while both low and very high levels of DHEAS are associated with poor cognitive function. There are no significant associations among women. These findings differ from those in a previous cross-sectional analysis based on the Taiwan study and underscore the importance of using prospective data to examine the effects of DHEAS on health. The evidence based on this and other longitudinal studies suggests that endogenous DHEAS is related to health outcomes for men, but not women, in both Western and non-Western populations.
doi:10.1016/j.exger.2007.05.005
PMCID: PMC2968710  PMID: 17604586
Dehydroepiandrosterone; Dehydroepiandrosterone sulfate; Health; Mental Health; Longitudinal Survey; Aged; Taiwan
13.  The Role of Life Satisfaction and Depressive Symptoms in All-cause Mortality 
Psychology and aging  2009;24(3):696-702.
The objective of our study was to investigate whether life satisfaction and depressive symptoms are independent predictors of mortality in a non-Western sample of adults. The sample included 5,131 adults (aged 50 – 95 at baseline) in Taiwan who participated in the Survey of Health and Living Status of the Near Elderly and Elderly. There were 1,815 deaths recorded over a 10-year period. Higher life satisfaction significantly predicted lower risk of mortality after controlling for age, sex, education, marital status and health status. Depressive symptoms significantly predicted higher risk of mortality. A significant interaction with age revealed that the protective effect of life satisfaction weakened with age. The results suggest that life satisfaction and depressive symptoms independently predict mortality risk in adults.
doi:10.1037/a0016777
PMCID: PMC2759085  PMID: 19739925
life satisfaction; depressive symptoms; mortality; Taiwan
14.  Improving Mortality Prediction Using Biosocial Surveys 
American Journal of Epidemiology  2009;169(6):769-779.
The authors used data from a nationally representative survey of 933 adults aged 54 years or older (mean age = 66.2 years; standard deviation, 8.0) in Taiwan to explore whether mortality prediction at older ages is improved by the use of 3 clusters of biomarkers: 1) standard cardiovascular and metabolic risk factors; 2) markers of disease progression; and 3) nonclinical (neuroendocrine and immune) markers. They also evaluated the extent to which these biomarkers account for the female advantage in survival. Estimates from logistic regression models of the probability of dying between 2000 and 2006 (162 deaths; mean length of follow-up = 5.8 years) showed that inclusion of each of the 3 sets of markers significantly (P = 0.024, P = 0.002, and P = 0.003, respectively) improved discriminatory power in comparison with a base model that adjusted for demographic characteristics, smoking, and baseline health status. The set of disease progression markers and the set of nonclinical markers each provided more discriminatory power than standard risk factors. Most of the excess male mortality resulted from the men being more likely than women to smoke, but each of 3 markers related to disease progression or inflammation (albumin, neutrophils, and interleukin-6) explained more than 10% of excess male mortality.
doi:10.1093/aje/kwn389
PMCID: PMC2732975  PMID: 19147742
biological markers; mortality; risk factors; sex factors; Taiwan

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