A cohort study of self-perception of ageing and all-cause mortality among older adults in China: a multiple mediators analysis.

BACKGROUND: Positive self-perception of aging (SPA) is a well-known predictor of longevity, while how and to what extent SPA is linked with all-cause mortality among older adults is still unclear. This study aims to elucidate the relationship between positive SPA and all-cause mortality and its potential mediators among Chinese older adults. METHODS: This is a 20-year dynamic cohort study conducted among 22,957 older adults aged ≥ 65 years old from a nationally representative sample. Positive SPA was measured using a validated 7-item scale. Potential mediators including health behaviors and social participation were collected using a self-reported questionnaire. Cox proportional hazards regression models were conducted to examine the association between positive SPA and all-cause mortality. A mediation analysis was conducted to determine whether health behaviors and social participation mediated the association between SPA and all-cause mortality. RESULTS: Throughout follow-up (median [interquartile range], 46 [21-84] months), all-cause mortality was 87.4%. Compared with older adults with the lowest quartile positive SPA, hazard ratio(HR) of all-cause mortality among older adults with the second, third, and fourth quartile of positive SPA was 0.96(95%CI:0.93-1.00), 0.93(95%CI:0.90-0.99), and 0.92(95%CI:0.87-0.96) respectively after controlling for all potential mediators and covariates. The mediation analysis showed that regular daily vegetable intake, physical activity, and high social participation explained 41.1-48.5% of the variance in the association between positive SPA and all-cause mortality. CONCLUSIONS: In this cohort study, we found that high positive SPA was associated with decreased all-cause mortality directly, and indirectly through healthy lifestyle behaviors and social participation. These findings suggest that interventions targeted at promoting or maintaining positive SPA may contribute to healthy ageing among older adults in China.

How does urbanization affect the cognitive function among older adults: A geospatial analysis in China.

There has been a plethora of studies on urbanization and older adults, and more recent ones on how older adults adapt to this process with their cognitive competence. Yet it has been unclear about the relationship between them, like how the level and rate of urbanization affect the cognitive function among older adults. This study sourced, formed, and analyzed a set of geospatial big datasets from different sources, such as the Chinese Longitudinal Healthy Longevity Survey (CLHLS) data, and the NPP/VIIRS nighttime light (NTL) data. Results showed a generally negative linear association between the rate of urbanization and cognitive performance among older adults in China. The "U" shaped non-linear relationship between urbanization level and cognitive function, as well as the tipping point, were identified. At the same time, it should be noted that mediators such as education, physical activity, social activity, and community elderly service might be able to mitigate these negative associations. Furthermore, older adults living in eastern regions or urban areas appeared to have better cognitive function than those living in mid-western regions or rural areas in China. The findings also pointed to the importance of focusing on older adults with poor cognitive health status in rapidly urbanizing areas.

Bi-directional association between outdoor or social activities and cognitive function: do the PM2.5 exposure catalyze the detrimental inactivity-poor cognition cycle?

BACKGROUND: Previous research has shown that lack of leisure activities, either outdoor or social activities, impedes cognitive function. However, the interrelationship between poor cognition and deficient activities is understudied. In addition, whether exposure to air pollution, such as PM2.5, can accelerate the detrimental 'inactivity-poor cognition' cycle, is worthy of investigation. METHODS: We used data from the 2008, 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). We assessed the frequency of outdoor or social activities at each wave. The cognitive function was examined using a China-Modified Mini-mental State Examination. We estimated the residential exposure to fine particular matter (PM2.5) via a satellite-based model. We applied cross-lagged panel (CLP) model to examine the bi-directional relationship between outdoor or social activities and cognitive function. We then examined the effect of PM2.5 exposure with sequent cognitive function and activities using generalized estimation equation (GEE) model. FINDINGS: Overall, we observed significant bi-directional associations between outdoor or social activities and cognitive function. Participants with better cognitive function in the last wave were more likely to engage in outdoor or social activities in the following wave (outdoor activities: ß = 0.37, 95% CI [0.27,0.48], P < 0.01; social activities: ß = 0.05, 95% CI [0.02,0.09] P < 0.01). Meanwhile, higher engagement in outdoor or social activities in the last wave was associated with more favorable cognitive function in the following wave (outdoor activities: ß = 0.06, 95% CI [0.03,0.09], P < 0.01; social activities: ß = 0.10, 95% CI [0.03,0.18], P < 0.01). Notably, an increase in PM2.5 exposure during the preceding year was significantly associated with a declining cognitive function (ß = -0.05, 95% CI [-0.08,-0.03], P < 0.01), outdoor activities (ß = -0.02, 95% CI [-0.04, -0.01], P < 0.01) and social activities (ß = -0.02, 95% CI [-0.02, -0.01], P < 0.01) in the current year; the lagged effects of the PM2.5 exposure in the past year of the last wave on activities and cognitive function of the following wave were also observed. INTERPRETATION: Our findings not only indicate the bi-directional links between the frequency of outdoor or social activities and cognitive function, but also report that PM2.5 exposure plays a role in catalyzing the detrimental inactivity-poor cognition cycle. Future research should investigate whether the policy-driven interventions, such as clean air policies, can break the unfavorable activity-cognition cycle, and thereby promoting health from the dual gains in leisure activities and cognition.

The impact of carbon emissions from lag fertilization on wheat production.

This study examines the influence of lag fertilization techniques on Pakistani wheat production, highlighting the need to understand and mitigate the environmental impacts of farming methods. The basic purpose of this study is to investigate the impact of CO2 emission from fertilization and other factors on wheat production in Pakistan, using a time series of data from 1990 to 2020. CO2 emission from fertilization (CO2EF) is estimated using the default values provided by the IPCC guidelines. The ARDL approach analyses the short-run and long-run effects of CO2EF, technology level, energy use, agricultural land, and agricultural labor on wheat production. The results show that all factors have significantly impacted wheat production in Pakistan at levels of 1% and 5% significance, both in the short and long run. These findings suggest that reducing CO2EF, technology level, energy use, agricultural land, and agricultural labor on wheat production can help to increase wheat production in Pakistan. The study also highlights the importance of adopting sustainable and efficient fertilization practices, exploring alternative fertilizers, and using crop rotation systems to mitigate the adverse effects of carbon emissions from nitrogen fertilization, energy use, and the use of technology. These measures can contribute to a more sustainable and climate-resilient agriculture sector in Pakistan.

Genetic associations with longevity are on average stronger in females than in males.

It is long observed that females tend to live longer than males in nearly every country. However, the underlying mechanism remains elusive. In this study, we discovered that genetic associations with longevity are on average stronger in females than in males through bio-demographic analyses of genome-wide association studies (GWAS) dataset of 2178 centenarians and 2299 middle-age controls of Chinese Longitudinal Healthy Longevity Study (CLHLS). This discovery is replicated across North and South regions of China, and is further confirmed by North-South discovery/replication analyses of different and independent datasets of Chinese healthy aging candidate genes with CLHLS participants who are not in CLHLS GWAS, including 2972 centenarians and 1992 middle-age controls. Our polygenic risk score analyses of eight exclusive groups of sex-specific genes, analyses of sex-specific and not-sex-specific individual genes, and Genome-wide Complex Trait Analysis using all SNPs all reconfirm that genetic associations with longevity are on average stronger in females than in males. Our discovery/replication analyses are based on genetic datasets of in total 5150 centenarians and compatible middle-age controls, which comprises the worldwide largest sample of centenarians. The present study's findings may partially explain the well-known male-female health-survival paradox and suggest that genetic variants may be associated with different reactions between males and females to the same vaccine, drug treatment and/or nutritional intervention. Thus, our findings provide evidence to steer away from traditional view that "one-size-fits-all" for clinical interventions, and to consider sex differences for improving healthcare efficiency. We suggest future investigations focusing on effects of interactions between sex-specific genetic variants and environment on longevity as well as biological function.

Trends in the prevalence of cognitive impairment at old age in China, 2002-2018.

INTRODUCTION: China has the world's largest number of older adults with cognitive impairment (CI). We aimed to examine secular trends in the prevalence of CI in China from 2002 to 2018. METHODS: Generalized estimating equations (GEE) was used to assess changes in CI trend in 44,154 individuals (72,027 observations) aged 65 to 105 years old. RESULTS: The prevalence of CI increased from 2002 to 2008 and then decreased until 2018. The age-standardized prevalence increased from 25.7% in 2002, 26.1% in 2005, to 28.2% in 2008, then decreased to 26.0% in 2011, 25.3% in 2014, and 24.9% in 2018. Females and those ≥ 80 years old had greater CI prevalence. DISCUSSION: The prevalence of CI showed an inverted U shape from early 2000s to late 2010s with a peak in 2008. Follow-up studies are needed to confirm the decreasing trend after 2008 and examine the contributing factors and underlying mechanisms of this trend. HIGHLIGHTS: Generalized estimating equations (GEE) were used to assess trends of changes in cognitive impairment (CI). CI prevalence in China increased from 2002 to 2008 and then decreased until 2018. Females and those ≥ 80 years old had greater CI prevalence. Stroke, diabetes, and cigarette smoking were risk factors for CI.

Assessing the carbon emission performance of digital greening synergistic transformation: evidence from the dual pilot projects in China.

Digital greening synergistic transformation (DGST) is a new engine for achieving dual carbon targets. Using panel data from 281 Chinese cities between 2003 and 2019, this study investigates the effect and transmission mechanism of the DGST on carbon emission performance. It is based on the quasi-natural experiments of the dual pilot projects "Broadband China" and "Low-carbon City", as well as the multi-period difference-in-difference method. The empirical findings are as follows: (1) DGST, represented by the dual pilot projects, effectively enhances carbon emission performance. Compared to the isolated "Broadband China" and "Low-Carbon City" pilot projects, establishing dual pilot projects generates a more pronounced carbon emission reduction effect through synergistic effects. (2) In terms of dynamic effects, the carbon emission reduction effect in dual pilot cities appears in the first year following initiation, indicating a certain temporal aspect to this effect. (3) Mechanism analysis reveals that the impact of DGST on carbon emission performance is channeled through two pathways: industrial structural adjustment and low-carbon technology innovation. (4) The positive impact of DGST on carbon emission performance exhibits heterogeneity, primarily present in cities with higher levels of financial technology, human capital, and new infrastructure development. It implies that the implementation of DGST necessitates adequate human, financial, and material support. In conclusion, this research contributes empirical evidence for further exploring policy synergies, offering support for achieving dual carbon targets through DGST.

Leisure Participation and Cognitive Impairment Among Healthy Older Adults in China.

Leisure participation is beneficial to various health outcomes. This study examined a comprehensive list of leisure activities in relation to incidence of cognitive impairment among healthy older adults (65+) in China. Using data from the 2002 to 2018 Chinese Longitudinal Healthy Longevity Survey, we found that most of the leisure activities were protective of cognitive decline and three leisure activities (watching TV, doing housework, and playing cards/mah-jong) stood out as the most important ones. Additionally, our results revealed subgroup variations in the association between leisure participation and cognitive function: Leisure activities such as reading newspapers/books (not significant for the illiterate), gardening (not significant for the illiterate), and regular exercise (not significant for the rural residents) had different effects across different demographic social groups. Our findings suggest that intervention programs designed to prevent cognitive decline for older adults should consider subgroup and cultural variations in order to yield the best outcomes.

Association of Long-term Exposure to Ambient Air Pollution With Cognitive Decline and Alzheimer's Disease-Related Amyloidosis.

BACKGROUND: Air pollution induces neurotoxic reactions and may exert adverse effects on cognitive health. We aimed to investigate whether air pollutants accelerate cognitive decline and affect neurobiological signatures of Alzheimer's disease (AD). METHODS: We used a population-based cohort from the Chinese Longitudinal Healthy Longevity Survey with 31,573 participants and a 10-year follow-up (5878 cognitively unimpaired individuals in Chinese Longitudinal Healthy Longevity Survey followed for 5.95 ± 2.87 years), and biomarker-based data from the Chinese Alzheimer's Biomarker and Lifestyle study including 1131 participants who underwent cerebrospinal fluid measurements of AD-related amyloid-ß (Aß) and tau proteins. Cognitive impairment was determined by education-corrected performance on the China-Modified Mini-Mental State Examination. Annual exposures to fine particulate matter (PM2.5), ground-level ozone (O3), and nitrogen dioxide (NO2) were estimated at areas of residence. Exposures were aggregated as 2-year averages preceding enrollments using Cox proportional hazards or linear models. RESULTS: Long-term exposure to PM2.5 (per 20 µg/m3) increased the risk of cognitive impairment (hazard ratio, 1.100; 95% CI: 1.026-1.180), and similar associations were observed from separate cross-sectional analyses. Exposures to O3 and NO2 yielded elevated risk but with nonsignificant estimates. Individuals exposed to high PM2.5 manifested increased amyloid burdens as reflected by cerebrospinal fluid-AD biomarkers. Moreover, PM2.5 exposure-associated decline in global cognition was partly explained by amyloid pathology as measured by cerebrospinal fluid-Aß42/Aß40, P-tau/Aß42, and T-tau/Aß42, with mediation proportions ranging from 16.95% to 21.64%. CONCLUSIONS: Long-term exposure to PM2.5 contributed to the development of cognitive decline, which may be partly explained by brain amyloid accumulation indicative of increased AD risk.

Anti-Inflammatory Dietary Diversity and Depressive Symptoms among Older Adults: A Nationwide Cross-Sectional Analysis.

The purpose of this study was to associate the anti-inflammatory dietary diversity and depressive symptoms among a nationwide sample of Chinese older adults. We used data from the 2018 wave of Chinese longitudinal healthy longevity survey (CLHLS). We assessed depressive symptoms using the 10 items of the center for epidemiologic studies depression scale (CES-D-10). Based on the dietary diversity index (DDI) generated by previous studies, we construct two novel indicators: the protein-enriched dietary diversity index diet (PEDDI) and the anti-inflammatory dietary diversity index diet (AIDDI). We used multivariate logistic models to evaluate the associations of DDI, PEDDI, and AIDDI with depressive symptoms, statistically adjusted for a range of potential confounders. A total of 12,192 participants (mean age 83.6 years) were included in the analysis. We found that participants with a higher score of DDI (OR = 0.91, 95% CI: 0.89-0.92) and PEDDI (OR = 0.91, 95% CI: 0.88-0.93) showed lower odds of having depressive symptoms, while the association between AIDDI and depressive symptoms was more marked (OR = 0.80, 95% CI: 0.78-0.83). The associations remained in subgroup analyses and sensitivity analyses. The results indicate that intaking diversified diet, particularly anti-inflammatory foods, may be associated with a lower risk of depressive symptoms. The findings of this study, if confirmed as causal, provide evidence that an intervention of adopting an anti-inflammatory diversified diet may reduce the burden of depression among older adults.

The Effects of "Diet-Smoking-Gender" Three-Way Interactions on Cognitive Impairment among Chinese Older Adults.

Investigations on gender variations in the risk factors of cognitive impairment are required to promote future precision medicine among older adults, as well as to contribute to a better understanding of the "male-female health-survival paradox". With this study, we aimed to investigate the effects of "diet-smoking-gender" three-way interactions on cognitive impairments among Chinese older adults. We conducted a 16-year prospective cohort study among 15,953, 15,555, 16,849, 9716, 7116, and 13,165 older adults from the 2002, 2005, 2008-2009, 2011-2012, 2014, and 2017-2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), respectively. Cognitive impairment was measured by the Mini-Mental State Examination (MMSE). The dietary diversity score (DDS) was calculated using the CLHLS food frequency questionnaire. Generalized estimating equations (GEE) were used to assess the "diet-smoking-gender" three-way interaction effects on cognitive impairment across the six waves of CLHLS. We found that higher dietary diversity was associated with lower probability of cognitive impairment among older adults (OR = 0.92; 95%CI = 0.90, 0.98). However, smoking behavior may negatively influence the protective effect of higher dietary diversity on cognitive function among females (OR = 1.26; 95%CI = 1.07, 1.49). Our findings imply that we should take gender differences and lifestyle behaviors into consideration in implementing dietary interventions to improve cognitive function among older adults.

Associations of Humidity and Temperature With Cataracts Among Older Adults in China.

Background: The burden of cataracts was substantial in the current aging world. However, few epidemiological studies have examined the associations between climate and weather conditions and cataract in older populations. We aimed to investigate the associations of air relative humidity and temperature with cataracts in older adults in China. Methods: We used the cohort data from 2002, 2005, 2008, 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 62,595 Chinese older adults aged between 65 and 105 years were included in the analyses. City-level annual average air humidity and temperature during 2001 and 2017 (before the survey year) was used to measure population exposure. A cataract was self-reports based on the medical record or the doctor's diagnosis and 8,071 older adults had cataract. Covariates included socio-demographic, health status, lifestyles, and chronic conditions. We adopted the Generalized estimation equation (GEE) model to analyze the associations of relative humidity and temperature with cataracts. Results: We found that the average relative humidity (OR: 0.99; 95% CI: 0.98-0.99) in the past year was inversely associated with cataract likelihoods in older adults and a positive association between temperature (OR: 1.04; 95%CI: 1.03,1.05) in the past year and cataract likelihoods in older adults. The associations were robust in stratified analyses by sex, urban/rural residence, and education level. Furthermore, we found a nonlinear J-shaped relationship between temperature and cataract prevalence. Conclusion: Our findings provide the evidence that higher temperature and low relative humidity may be associated with cataracts in older adults.

Association between outdoor artificial light at night and sleep duration among older adults in China: A cross-sectional study.

BACKGROUND: Light after dusk disrupts the circadian rhythms and shifts the timing of sleep later; but it is unknown whether outdoor artificial light at night (ALAN) affects sleep quality. This study aimed to explore the association between residential outdoor ALAN and sleep duration in a nationally representative sample of Chinese older adults. METHODS: We examined the cross-sectional associations of outdoor ALAN with self-reported sleep duration in 13,474 older adults participating in the 2017-2018 wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Outdoor ALAN exposure was estimated at the residence level using satellite images. We applied generalized linear mixed models to investigate the association between ALAN exposure and sleep duration. We performed stratified analyses by age, sex, education, and household income levels. Moreover, we used multi-level logistic regression models to investigate the effects of ALAN on the short sleep duration (≤6 h) and the long sleep duration (>8 h), respectively, in reference to sleep for >6-8 h per day. RESULTS: We found a significant association between outdoor ALAN intensity and sleep duration. The highest quartile of ALAN was associated with 17.04 (95% CI: 9.42-24.78) fewer minutes of sleep as compared to the lowest quartile. The reductions in sleep duration per quartile change in ALAN were greater in the young old (≥65-85 years) and in those with higher levels of education, and those with higher household income, respectively. We did not detect a sex difference. In addition, those in the highest quartile of ALAN were more likely to report a 25% (95% CI: 10%-42%) increase in short sleep (<6 h), and a 21% (95% CI: 9%-31%) decrease in long sleep (>8 h). CONCLUSIONS: Increasing outdoor nighttime light intensity surrounding residences was associated with shorter sleep duration in older residents in China. This finding implies the importance of urban outdoor artificial light management as a potential means to lower the public health burden of sleep disorders.

Time trend analysis of leisure-time activity participation among young-old adults in China 2002-2018.

BACKGROUND: To examine the time trends of leisure activity engagement among young-old adults aged 65-74 in China over a 16-year period. METHODS: Data for a nationally representative sample of young-old adults was sourced from the 2002-2018 Chinese Longitudinal Healthy Longevity Survey (N = 9504). Generalized estimating equations regressions were implemented to assess temporal trends for 10 different leisure-time activities. We also evaluated time trends for solitary versus social leisure-time activities. RESULTS: Young-old adults were less likely to engage in any form of social activities (e.g. participate in social events) over time, controlling for other confounders such as age, sex, education, income, and health characteristics. Trends in outdoor activities participation and tourism also declined over 2002-2014, but reversed in 2018. In contrast, solitary leisure activities (e.g. watching TV) became more popular. There was a significant spike in the likelihood of keeping pets from 2011 onwards, especially among urbanites. CONCLUSIONS: The future elderly in China have tended towards home-bound and solitary leisure activities over time, which warrants policy attention and public health interventions to reverse such trends.

Long-term ozone exposure and cognitive impairment among Chinese older adults: A cohort study.

Ambient particulate matter pollution has been linked to impaired cognitive performance, but the effect of ambient ozone exposure on cognitive function remains largely unknown. We examined the association of long-term ozone exposure with the risk of cognitive impairment among a national representative cohort of 9,544 Chinese older adults (aged 65 years and over) with baseline normal cognition from the Chinese Longitudinal Healthy Longevity Survey (2005-2018). The ozone exposure of each participant was measured by annual mean ozone concentrations for the county of residence. Cognitive function was assessed by the Chinese version of the Mini-Mental State Examination (MMSE). We defined cognitive impairment as an MMSE score below 18 points accompanied by an MMSE score that declined ≥ 4 points from baseline. Cox proportional hazards models were applied to explore the association of ozone exposure with cognitive impairment. During the mean follow-up time of 6.5 years, 2,601 older adults developed cognitive impairment. Each 10-µg/m3 increase in annual mean ozone exposure was associated with a 10.4% increased risk of cognitive impairment. The exposure-response relationship between ozone exposure and risk of cognitive impairment showed a linear trend. Sensitivity analyses revealed the association to be robust. We found that older adults from Eastern, Central, and Southern China were particularly susceptible. Our results show that ozone is a risk factor for late-life cognitive decline. Reducing ambient ozone pollution may help delay the onset of cognitive impairment among older adults.

The obesity paradox is mostly driven by decreased noncardiovascular disease mortality in the oldest old in China: a 20-year prospective cohort study.

National and international recommendations of healthy body mass index (BMI) are primarily based on evidence in young and middle-aged populations, with an insufficient representation of the oldest old (aged ≥80 years). Here, we report associations between BMI and mortality risk in 27,026 community-dwelling oldest old (mean age, 92.7 ± 7.5 years) in China from 1998 to 2018. Nonlinear curves showed reverse J-shaped associations of BMI with cardiovascular disease (CVD), non-CVD and all-cause mortality, with a monotonic decreased risk up to BMIs in the overweight and mild obesity range and flat hazard ratios thereafter. Compared to normal weight, overweight and obesity were significantly associated with decreased non-CVD and all-cause mortality, but not with CVD mortality. Similar associations were found for waist circumference. Our results lend support to the notion that optimal BMI in the oldest old may be around the overweight or mild obesity range and challenge the application of international and national guidelines on optimal BMI in this age group.

Influences of temperature and humidity on cardiovascular disease among adults 65 years and older in China.

Background: The burden of cardiovascular disease (CVD) on the current aging society in China is substantial. Climate change, including extreme temperatures and humidity, has a detrimental influence on health. However, epidemiological studies have been unable to fully identify the association between climate change and CVD among older adults. Therefore, we investigated the associations between temperature and relative humidity and CVD among older adults in China. Methods: We used cohort data from the China Longitudinal Health and Longevity Survey (CLHLS) conducted in 2002, 2005, 2008, 2011, 2014, and 2018. A total of 39,278 Chinese adults 65 years and older participated in the analyses. The average annual temperatures and relative humidity during 2001 and 2017 (before the survey year) at the city level in China were used as the exposure measures. We selected patients with hypertension, heart disease, and stroke to create a sample of CVD patients. The associations between temperature and relative humidity and CVD were analyzed using the generalized estimation equation (GEE) model. Covariates included sociodemographic factors, health status, lifestyle, and cognitive function. Results: The average annual temperature was negatively correlated with the prevalence of CVD. Every 1°C increase in the average annual temperature reduced the rates of hypertension by 3% [odds ratio (OR): 0.97; 95% confidence interval (CI): 0.96-0.97], heart disease by 6% (OR: 0.94; 95% CI: 0.92-0.95), and stroke by 5% (OR: 0.95; 95% CI: 0.94-0.97). The results of the analyses stratified by sex, urban/rural residence, and educational level were robust. The average annual relative humidity was inversely associated with the likelihood of CVD among older adults. Every 1% increase in the average annual relative humidity reduced the rates of hypertension by 0.4% (OR: 0.996; 95% CI: 0.99-1.00), heart disease by 0.6% (OR: 0.994; 95% CI: 0.99-1.00), and stroke by 0.08% (OR: 0.992; 95% CI: 0.98-1.00). However, the effects were more obvious with higher humidity levels (>70). Conclusion: Our findings suggest that higher temperatures and relative humidity may reduce the risk of CVD among older adults.

Association between allostatic load and mortality among Chinese older adults: the Chinese Longitudinal Health and Longevity Study.

BACKGROUND: Allostatic load (AL) has shown that high burden of AL is associated with increased risk of adverse outcomes, but little attention has been paid to China with largest ageing population in the world. OBJECTIVE: This study is to examine the association between AL and all-cause mortality among Chinese adults aged at least 60 years. DESIGN: Population-based prospective cohort study. SETTING: In 2011-2012, an ancillary study, in which a blood test was added, including a total of 2439 participants, was conducted in eight longevity areas in the Chinese Longitudinal Healthy Longevity Survey. PARTICIPANTS: The final analytical sample consisted of 1519 participants (mean±SD age: men 80.5±11.3 years; women 90.2±11.8 years and 53% women). PRIMARY OUTCOME MEASURE: Cox models were used to examine the association between AL and mortality among men and women, separately. Analyses were also adjusted for potential confounders including age, ethnicity, education and marital status, smoking and exercise. RESULTS: Male with a medium AL burden (score: 2-4) and high AL burden (score: 5-9) had a 33% and 118% higher hazard of death, respectively, than those with a low AL burden (score: 0-1). We did not find significant difference between females with different levels of AL burden. CONCLUSION: Higher AL burden was associated with increased all-cause mortality among Chinese men aged at least 60 years. However, we did not find strong association among women. In conclusion, Intervention programmes targeting modifiable components of the AL burden may help prolong lifespan for older adults, especially men, in China.

Type of tea consumption and depressive symptoms in Chinese older adults.

BACKGROUND: Existing research indicates that tea drinking may exert beneficiary effects on mental health. However, associations between different types of tea intake and mental health such as depression have not been fully examined. The purpose of this study was to examine the associations of green tea, fermented tea, and floral tea consumption with depressive symptoms. METHODS: We used data from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey, a nationwide survey on older adults in mainland China. A total of 13,115 participants (mean age 83.7 years, 54.2% were women) with valid responses were included in the analysis. The type (green, fermented [black, Oolong, white, yellow, dark, and compressed teas], and floral) and the frequency of tea consumption were recorded, and depressive symptoms were assessed using 10-item of the Center for Epidemiologic Studies Depression Scale (CES-D-10). We examined the associations between the type and the frequency of tea intake and depression, controlling for a set of demographic, socioeconomic, psychosocial, behavioral, and health-related variables. RESULTS: Overall, intakes of green tea, fermented tea, and floral tea were all significantly associated with lower prevalence of depressive symptoms, independent of other risk factors. Compared with the group of no tea intake, the adjusted ORs of depressive symptoms for daily green tea, fermented tea, and floral tea intake were 0.85 (95% CI: 0.76-0.95), 0.87 (95% CI: 0.76-0.99), and 0.70 (95% CI: 0.59-0.82), respectively. Linear associations were observed between the frequencies of all three types of tea intake and depressive symptoms (P < 0.05 for trends for all three types). The associations of the type and the frequency of tea intake and depressive symptoms were robust in several sensitivity analyses. CONCLUSIONS: Among Chinese older adults, regularly consumed any type of tea (green, fermented, or floral) were less likely to show depressive symptoms, the associations seemed more pronounced among floral tea and green tea drinkers.

Integrated genetic analyses revealed novel human longevity loci and reduced risks of multiple diseases in a cohort study of 15,651 Chinese individuals.

There is growing interest in studying the genetic contributions to longevity, but limited relevant genes have been identified. In this study, we performed a genetic association study of longevity in a total of 15,651 Chinese individuals. Novel longevity loci, BMPER (rs17169634; p = 7.91 × 10-15 ) and TMEM43/XPC (rs1043943; p = 3.59 × 10-8 ), were identified in a case-control analysis of 11,045 individuals. BRAF (rs1267601; p = 8.33 × 10-15 ) and BMPER (rs17169634; p = 1.45 × 10-10 ) were significantly associated with life expectancy in 12,664 individuals who had survival status records. Additional sex-stratified analyses identified sex-specific longevity genes. Notably, sex-differential associations were identified in two linkage disequilibrium blocks in the TOMM40/APOE region, indicating potential differences during meiosis between males and females. Moreover, polygenic risk scores and Mendelian randomization analyses revealed that longevity was genetically causally correlated with reduced risks of multiple diseases, such as type 2 diabetes, cardiovascular diseases, and arthritis. Finally, we incorporated genetic markers, disease status, and lifestyles to classify longevity or not-longevity groups and predict life span. Our predictive models showed good performance (AUC = 0.86 for longevity classification and explained 19.8% variance of life span) and presented a greater predictive efficiency in females than in males. Taken together, our findings not only shed light on the genetic contributions to longevity but also elucidate correlations between diseases and longevity.