Population aging has emerged as a major demographic trend around the globe. Aging is a process th... more Population aging has emerged as a major demographic trend around the globe. Aging is a process that is determined by millions of genetic factors. The identification of the set of genetic factors that has a significant role in the aging process is a highly challenging task. This paper studies the association between genetic factors and the aging rate. We first calculate the so-called polygenic risk score (PRS) by following a well-designed algorithm for the selection of the significant single nucleotide polymorphisms (SNPs) and subsequently considering a weighted sum of those significant SNPs. Next, we construct a new mortality model, which allows the aging rate to depend on the PRS. Our statistical analysis is based on a rich dataset from the Health and Retirement Study.
Objective:A suboptimal diet and nutritional deficiencies can have important influences on health ... more Objective:A suboptimal diet and nutritional deficiencies can have important influences on health with significant impact among older adults. This study aims to assess the presence of suboptimal dietary intake among older Americans and identify risk and protective factors influencing diet quality.Design:Cross-sectional secondary analysis.Setting:USA.Participants:A nationally representative sample of 5614 community-dwelling older adults over age 54 in the Health and Retirement Study – Health Care and Nutrition Survey.Results:Overall, only 10·7 % of respondents had a good quality diet (Healthy Eating Index score 81 and above); the majority had diets considered poor or needing improvement. Less than 50 % of respondents met dietary guidelines and nutritional goals for most individual food groups and nutrients. Respondents with low socio-economic status, fewer psychosocial resources and those who had limited access to healthy food outlets were more likely to have a diet of suboptimal qual...
We aimed to evaluate associations between a comprehensive set of factors, including genetics and ... more We aimed to evaluate associations between a comprehensive set of factors, including genetics and childhood and adulthood circumstances, and a novel aging measure, Phenotypic Age (PhenoAge), which has been shown to capture mortality and morbidity risk in the U.S. population. Using data from 2339 adults (aged 51+) from the U.S. Health and Retirement Study, we found that together all 11 study domains (4 childhood and adulthood circumstances domains, 5 polygenic scores [PGSs] domains, and 1 demographics, and 1 behaviors domains) accounted for about 30% of variance in PhenoAge after accounting for chronological age. Among the 4 circumstances domains, adulthood adversity was the largest contributor (9%), while adulthood socioeconomic status (SES), childhood adversity, and childhood SES accounted for 2.8%, 2.1%, 0.7%, respectively. All PGSs contributed 3.8% of variance in PhenoAge (after accounting for chronological age). Further, using Hierarchical Clustering, we identified 6 distinct sub...
International journal of public health, Jan 11, 2016
To estimate prevalence of diabetes mellitus (DM), success in diagnosing, and methods of diabetes ... more To estimate prevalence of diabetes mellitus (DM), success in diagnosing, and methods of diabetes management in China. China Health and Retirement Longitudinal Study, a representative survey of the Chinese population at least 45Â years old, is used to estimate diabetes and prediabetes prevalence, diagnosis, and treatment and their associations with residence, socioe-conomic, and demographic factors. Almost 60Â % of middle-aged and elderly Chinese have prediabetes or diabetes in 2011-2012. DM prevalence increases with age, but the oldest group is least likely to be diagnosed. Prevalence is higher with higher body mass index, fasting cholesterol, and larger waist circumference. Higher prevalence is found in urban areas among residents with urban registration status (the Chinese administrative registration system or hukou), especially in coastal regions. Better rates of diagnosis, management, and education regarding diabetes are strongly associated with urban hukou, living in coastal area...
Marital quality is an important factor for understanding the relationship between marriage and he... more Marital quality is an important factor for understanding the relationship between marriage and health. Low-quality relationships may not have the same health benefits as high-quality relationships. To understand the association between marital quality and health, we examined associations between two indicators of marital quality (marital support and marital strain) and two biomarkers of inflammation (interleukin-6 and C-reactive protein) among men and women in long-term marriages using data from the Survey of Midlife in the United States (N = 542). Lower levels of spousal support were associated with higher levels of inflammation among women but not men. Higher levels of spousal strain were weakly and inconsistently associated with higher levels of inflammation among women and men; the effects were diminished with the addition of psychosocial and behavioral covariates. These findings suggest marital quality is an important predictor of inflammation, especially among women.
Adverse experiences in early life have the ability to "get under the skin" and affect f... more Adverse experiences in early life have the ability to "get under the skin" and affect future health. This study examined the relative influence of adversities during childhood and adulthood in accounting for individual differences in pro-inflammatory gene expression in late life. Using a pilot-sample from the Health and Retirement Study (NÂ =Â 114) aged from 51 to 95, OLS regression models were run to determine the association between a composite score from three proinflammatory gene expression levels (PTGS2, ILIB, and IL8) and 1) childhood trauma, 2) childhood SES, 3) childhood health, 4) adult traumas, and 5) low SES in adulthood. Our results showed that only childhood trauma was found to be associated with increased inflammatory transcription in late life. Furthermore, examination of interaction effects showed that childhood trauma exacerbated the influence of low SES in adulthood on elevated levels of inflammatory gene expression-signifying that having low SES in adultho...
American journal of human biology : the official journal of the Human Biology Council
Concepts such as Allostatic Load, Framingham Risk Score, and Biological Age were developed to com... more Concepts such as Allostatic Load, Framingham Risk Score, and Biological Age were developed to combine information from multiple measures into a single latent variable that can be used to quantify a person's biological state. Given these varying approaches, the goal of this article is to compare how well these three measures predict subsequent all-cause and disease-specific mortality within a large nationally representative U.S. sample. Our study population consisted of 9,942 adults, ages 30 and above from National Health and Nutrition Examination Survey III. Receiver Operating Characteristic curves and Cox Proportional Hazard models for the whole sample and for stratified age groups were used to compare how well Allostatic Load, Framingham Risk Score, and Biological Age predict ten-year all-cause and disease-specific mortality in the sample, for whom there were 1,076 deaths over 96,420 person years of exposure. Overall, Biological Age predicted 10-year mortality more accurately ...
This study examined the influence of insulin resistance and inflammation on the association betwe... more This study examined the influence of insulin resistance and inflammation on the association between body composition and cognitive performance in older adults, aged 60-69 and aged 70 and older. Subjects included 1127 adults from NHANES 1999-2002. Body composition was categorized based on measurements of muscle mass and waist circumference as sarcopenic nonobese, nonsarcopenic obese, sarcopenic obese, and normal. Using OLS regression models, our findings suggest body composition is not associated with cognitive functioning in adults ages 60-69; however, for adults aged 70 and over, sarcopenia and obesity, either independently or concurrently, were associated with worse cognitive functioning relative to non-sarcopenic non-obese older adults. Furthermore, insulin resistance accounted for a significant proportion of the relationship between cognitive performance and obesity, with or without sarcopenia. Additionally, although high CRP was significantly associated with poorer cognitive fu...
The journals of gerontology. Series B, Psychological sciences and social sciences, 2015
There is growing interest in understanding how exposures in the residential environment relate to... more There is growing interest in understanding how exposures in the residential environment relate to cognitive function in older adults. The goal of this study is to determine if neighborhood-level exposure to fine particulate matter air pollution (PM2.5) is associated with cognitive function in a diverse, national sample of older U.S. adults. We use cross-sectional data on non-Hispanic black and white men and women aged 55 and older from the 2001/2002 Americans' Changing Lives Study (N = 780). EPA air monitoring data were linked to respondents using census tract identifiers. Cognitive function was assessed with tests of working memory and orientation. Negative binomial regression models were used to examine the association between PM2.5 and the number of errors on the cognitive assessment. Older adults living in areas with high concentrations of PM2.5 had an error rate 1.5 times greater than those exposed to lower concentrations, net of individual and neighborhood-level demographi...
Alzheimer’s disease (AD) extracts a heavy societal toll. The value of medical advances that delay... more Alzheimer’s disease (AD) extracts a heavy societal toll. The value of medical advances that delay onset of AD could be significant. Using data from nationally representative samples from the Health and Retirement Study (1998–2008) and Aging Demographics and Memory Study (2001–2009), we estimate the prevalence and incidence of AD and the formal and informal health care costs associated with it. We use microsimulation to project future prevalence and costs of AD under different treatment scenarios. We find from 2010 to 2050, the number of individuals ages 70+ with AD increases 153%, from 3.6 to 9.1 million, and annual costs increase from $307 billion ($181B formal, $126B informal costs) to $1.5 trillion. 2010 annual per person costs were $71,303 and double by 2050. Medicare and Medicaid are paying 75% of formal costs. Medical advances that delay onset of AD for 5 years result in 41% lower prevalence and 40% lower cost of AD in 2050. For one cohort of older individuals, who would go on...
Although education is consistently related to better cognitive performance, findings on the relat... more Although education is consistently related to better cognitive performance, findings on the relationship between education and age-associated cognitive change have been conflicting. Using measures of multiple cognitive domains from four waves of the Asset and Health Dynamics of the Oldest Old study, a representative sample of Americans aged 70 years and older, the authors performed growth curve modeling to examine the relationships between education, initial cognitive score, and the rate of decline in cognitive function. More years of education were linked to better initial performance on each of the cognitive tests, and higher levels of education were linked to slower decline in mental status. However, more education was unrelated to the rate of decline in working memory, and education was associated with somewhat faster cognitive decline on measures of verbal memory. These findings highlight the role of early-life experiences not only in long-term cognitive performance but also in...
Proceedings of the National Academy of Sciences, 2008
The male disadvantage in infant mortality underwent a surprising rise and fall in the 20th centur... more The male disadvantage in infant mortality underwent a surprising rise and fall in the 20th century. Our analysis of 15 developed countries shows that, as infant mortality declined over two centuries, the excess male mortality increased from 10% in 1751 to >30% by approximately 1970. Remarkably, since 1970, the male disadvantage in most countries fell back to lower levels. The worsening male disadvantage from 1751 until 1970 may be due to differential changes in cause-specific infant mortality by sex. Declines in infant mortality from infections and the shift of deaths to perinatal conditions favored females. The reduction in male excess infant mortality after 1970 can be attributed to improved obstetric practices and neonatal care. The additional male infants who survived because of better conditions were more likely to be premature or have low birth weight, which could have implications for their health in later life. This analysis provides evidence of marked changes in the sex ...
Population aging has emerged as a major demographic trend around the globe. Aging is a process th... more Population aging has emerged as a major demographic trend around the globe. Aging is a process that is determined by millions of genetic factors. The identification of the set of genetic factors that has a significant role in the aging process is a highly challenging task. This paper studies the association between genetic factors and the aging rate. We first calculate the so-called polygenic risk score (PRS) by following a well-designed algorithm for the selection of the significant single nucleotide polymorphisms (SNPs) and subsequently considering a weighted sum of those significant SNPs. Next, we construct a new mortality model, which allows the aging rate to depend on the PRS. Our statistical analysis is based on a rich dataset from the Health and Retirement Study.
Objective:A suboptimal diet and nutritional deficiencies can have important influences on health ... more Objective:A suboptimal diet and nutritional deficiencies can have important influences on health with significant impact among older adults. This study aims to assess the presence of suboptimal dietary intake among older Americans and identify risk and protective factors influencing diet quality.Design:Cross-sectional secondary analysis.Setting:USA.Participants:A nationally representative sample of 5614 community-dwelling older adults over age 54 in the Health and Retirement Study – Health Care and Nutrition Survey.Results:Overall, only 10·7 % of respondents had a good quality diet (Healthy Eating Index score 81 and above); the majority had diets considered poor or needing improvement. Less than 50 % of respondents met dietary guidelines and nutritional goals for most individual food groups and nutrients. Respondents with low socio-economic status, fewer psychosocial resources and those who had limited access to healthy food outlets were more likely to have a diet of suboptimal qual...
We aimed to evaluate associations between a comprehensive set of factors, including genetics and ... more We aimed to evaluate associations between a comprehensive set of factors, including genetics and childhood and adulthood circumstances, and a novel aging measure, Phenotypic Age (PhenoAge), which has been shown to capture mortality and morbidity risk in the U.S. population. Using data from 2339 adults (aged 51+) from the U.S. Health and Retirement Study, we found that together all 11 study domains (4 childhood and adulthood circumstances domains, 5 polygenic scores [PGSs] domains, and 1 demographics, and 1 behaviors domains) accounted for about 30% of variance in PhenoAge after accounting for chronological age. Among the 4 circumstances domains, adulthood adversity was the largest contributor (9%), while adulthood socioeconomic status (SES), childhood adversity, and childhood SES accounted for 2.8%, 2.1%, 0.7%, respectively. All PGSs contributed 3.8% of variance in PhenoAge (after accounting for chronological age). Further, using Hierarchical Clustering, we identified 6 distinct sub...
International journal of public health, Jan 11, 2016
To estimate prevalence of diabetes mellitus (DM), success in diagnosing, and methods of diabetes ... more To estimate prevalence of diabetes mellitus (DM), success in diagnosing, and methods of diabetes management in China. China Health and Retirement Longitudinal Study, a representative survey of the Chinese population at least 45Â years old, is used to estimate diabetes and prediabetes prevalence, diagnosis, and treatment and their associations with residence, socioe-conomic, and demographic factors. Almost 60Â % of middle-aged and elderly Chinese have prediabetes or diabetes in 2011-2012. DM prevalence increases with age, but the oldest group is least likely to be diagnosed. Prevalence is higher with higher body mass index, fasting cholesterol, and larger waist circumference. Higher prevalence is found in urban areas among residents with urban registration status (the Chinese administrative registration system or hukou), especially in coastal regions. Better rates of diagnosis, management, and education regarding diabetes are strongly associated with urban hukou, living in coastal area...
Marital quality is an important factor for understanding the relationship between marriage and he... more Marital quality is an important factor for understanding the relationship between marriage and health. Low-quality relationships may not have the same health benefits as high-quality relationships. To understand the association between marital quality and health, we examined associations between two indicators of marital quality (marital support and marital strain) and two biomarkers of inflammation (interleukin-6 and C-reactive protein) among men and women in long-term marriages using data from the Survey of Midlife in the United States (N = 542). Lower levels of spousal support were associated with higher levels of inflammation among women but not men. Higher levels of spousal strain were weakly and inconsistently associated with higher levels of inflammation among women and men; the effects were diminished with the addition of psychosocial and behavioral covariates. These findings suggest marital quality is an important predictor of inflammation, especially among women.
Adverse experiences in early life have the ability to "get under the skin" and affect f... more Adverse experiences in early life have the ability to "get under the skin" and affect future health. This study examined the relative influence of adversities during childhood and adulthood in accounting for individual differences in pro-inflammatory gene expression in late life. Using a pilot-sample from the Health and Retirement Study (NÂ =Â 114) aged from 51 to 95, OLS regression models were run to determine the association between a composite score from three proinflammatory gene expression levels (PTGS2, ILIB, and IL8) and 1) childhood trauma, 2) childhood SES, 3) childhood health, 4) adult traumas, and 5) low SES in adulthood. Our results showed that only childhood trauma was found to be associated with increased inflammatory transcription in late life. Furthermore, examination of interaction effects showed that childhood trauma exacerbated the influence of low SES in adulthood on elevated levels of inflammatory gene expression-signifying that having low SES in adultho...
American journal of human biology : the official journal of the Human Biology Council
Concepts such as Allostatic Load, Framingham Risk Score, and Biological Age were developed to com... more Concepts such as Allostatic Load, Framingham Risk Score, and Biological Age were developed to combine information from multiple measures into a single latent variable that can be used to quantify a person's biological state. Given these varying approaches, the goal of this article is to compare how well these three measures predict subsequent all-cause and disease-specific mortality within a large nationally representative U.S. sample. Our study population consisted of 9,942 adults, ages 30 and above from National Health and Nutrition Examination Survey III. Receiver Operating Characteristic curves and Cox Proportional Hazard models for the whole sample and for stratified age groups were used to compare how well Allostatic Load, Framingham Risk Score, and Biological Age predict ten-year all-cause and disease-specific mortality in the sample, for whom there were 1,076 deaths over 96,420 person years of exposure. Overall, Biological Age predicted 10-year mortality more accurately ...
This study examined the influence of insulin resistance and inflammation on the association betwe... more This study examined the influence of insulin resistance and inflammation on the association between body composition and cognitive performance in older adults, aged 60-69 and aged 70 and older. Subjects included 1127 adults from NHANES 1999-2002. Body composition was categorized based on measurements of muscle mass and waist circumference as sarcopenic nonobese, nonsarcopenic obese, sarcopenic obese, and normal. Using OLS regression models, our findings suggest body composition is not associated with cognitive functioning in adults ages 60-69; however, for adults aged 70 and over, sarcopenia and obesity, either independently or concurrently, were associated with worse cognitive functioning relative to non-sarcopenic non-obese older adults. Furthermore, insulin resistance accounted for a significant proportion of the relationship between cognitive performance and obesity, with or without sarcopenia. Additionally, although high CRP was significantly associated with poorer cognitive fu...
The journals of gerontology. Series B, Psychological sciences and social sciences, 2015
There is growing interest in understanding how exposures in the residential environment relate to... more There is growing interest in understanding how exposures in the residential environment relate to cognitive function in older adults. The goal of this study is to determine if neighborhood-level exposure to fine particulate matter air pollution (PM2.5) is associated with cognitive function in a diverse, national sample of older U.S. adults. We use cross-sectional data on non-Hispanic black and white men and women aged 55 and older from the 2001/2002 Americans' Changing Lives Study (N = 780). EPA air monitoring data were linked to respondents using census tract identifiers. Cognitive function was assessed with tests of working memory and orientation. Negative binomial regression models were used to examine the association between PM2.5 and the number of errors on the cognitive assessment. Older adults living in areas with high concentrations of PM2.5 had an error rate 1.5 times greater than those exposed to lower concentrations, net of individual and neighborhood-level demographi...
Alzheimer’s disease (AD) extracts a heavy societal toll. The value of medical advances that delay... more Alzheimer’s disease (AD) extracts a heavy societal toll. The value of medical advances that delay onset of AD could be significant. Using data from nationally representative samples from the Health and Retirement Study (1998–2008) and Aging Demographics and Memory Study (2001–2009), we estimate the prevalence and incidence of AD and the formal and informal health care costs associated with it. We use microsimulation to project future prevalence and costs of AD under different treatment scenarios. We find from 2010 to 2050, the number of individuals ages 70+ with AD increases 153%, from 3.6 to 9.1 million, and annual costs increase from $307 billion ($181B formal, $126B informal costs) to $1.5 trillion. 2010 annual per person costs were $71,303 and double by 2050. Medicare and Medicaid are paying 75% of formal costs. Medical advances that delay onset of AD for 5 years result in 41% lower prevalence and 40% lower cost of AD in 2050. For one cohort of older individuals, who would go on...
Although education is consistently related to better cognitive performance, findings on the relat... more Although education is consistently related to better cognitive performance, findings on the relationship between education and age-associated cognitive change have been conflicting. Using measures of multiple cognitive domains from four waves of the Asset and Health Dynamics of the Oldest Old study, a representative sample of Americans aged 70 years and older, the authors performed growth curve modeling to examine the relationships between education, initial cognitive score, and the rate of decline in cognitive function. More years of education were linked to better initial performance on each of the cognitive tests, and higher levels of education were linked to slower decline in mental status. However, more education was unrelated to the rate of decline in working memory, and education was associated with somewhat faster cognitive decline on measures of verbal memory. These findings highlight the role of early-life experiences not only in long-term cognitive performance but also in...
Proceedings of the National Academy of Sciences, 2008
The male disadvantage in infant mortality underwent a surprising rise and fall in the 20th centur... more The male disadvantage in infant mortality underwent a surprising rise and fall in the 20th century. Our analysis of 15 developed countries shows that, as infant mortality declined over two centuries, the excess male mortality increased from 10% in 1751 to >30% by approximately 1970. Remarkably, since 1970, the male disadvantage in most countries fell back to lower levels. The worsening male disadvantage from 1751 until 1970 may be due to differential changes in cause-specific infant mortality by sex. Declines in infant mortality from infections and the shift of deaths to perinatal conditions favored females. The reduction in male excess infant mortality after 1970 can be attributed to improved obstetric practices and neonatal care. The additional male infants who survived because of better conditions were more likely to be premature or have low birth weight, which could have implications for their health in later life. This analysis provides evidence of marked changes in the sex ...
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