Social isolation and likelihood of becoming centenarians: evidence from the Chinese longitudinal healthy longevity survey.

BACKGROUND: Social isolation, defined as an individual's lack of social connections, is particularly prevalent among older adults. However, its association with health outcomes among the oldest-old population (aged 80 and above) was understudied. AIMS: To examine the association between social isolation and the likelihood of becoming a centenarian among the oldest-old people in China, aiming to provide novel insights into promoting healthy aging and longevity. METHODS: Using data from The Chinese Longitudinal Healthy Longevity Survey, conducted in 22 provinces in mainland China since 1998, we performed a community-based, prospective nested case-control study. The primary outcome was survival to the age of 100 by 2018 (the end of follow-up). Information on social isolation and other covariates was collected via a questionnaire at baseline. The degree of social isolation was categorized as low, moderate, and high. Included (n = 5,716) were 1,584 identified centenarians and 4,132 controls (deceased before reaching 100 years), matched by age, sex, and year of entry. A conditional logistic regression model was used to evaluate the association between social isolation and the likelihood of becoming a centenarian, adjusting for demographic factors, lifestyle factors, chronic disease, potential disability, optimistic attitude, and perceived loneliness. RESULTS: Individuals with the highest social isolation score had lower odds of becoming centenarians (adjusted OR:0.82; 95% CI: 0.68, 0.98), relative to those with the least social isolation (P-value < 0.05), and this association persisted in sensitivity analyses. The association was more pronounced among ever smokers, compared to never smokers (P-value = 0.001). We did not observe significant interactions between social isolation and other covariates (P-value > 0.05 for all). CONCLUSIONS: This study highlights the inverse association between social isolation and the likelihood of becoming a centenarian, emphasizing the need for public health initiatives to combat isolation in the older population.

Leisure-time activities and disability among Chinese community-dwelling oldest old: evidence from the Chinese Longitudinal Healthy Longevity Study.

With the acceleration of population aging, disability in older adults is a growing public health problem; however, little is known about the role of specific leisure-time activities in affecting disability. This study prospectively examined the association of leisure-time activities with disability among the Chinese oldest old. A total of 14 039 adults aged 80 years or older (median age of 89.8 years) were enrolled from the Chinese Longitudinal Healthy Longevity Survey from 1998 to 2014. Disability was defined as the presence of concurrent impairment in activities of daily living and physical performance. Cox proportional hazards models were used to estimate the associations between leisure-time activities and disability. During a mean of 4.2 years (2.7 years) of follow-up, 4487 participants developed disability. Compared with participants who never engaged in leisure-time activities, participants who engaged in almost daily activities, including gardening, keeping domestic animals or pets, playing cards or mahjong, reading books or newspapers, and watching TV or listening to the radio had a lower risk of disability, with HRs of 0.78 (0.69-0.88), 0.64 (0.58-0.70), 0.74 (0.63-0.86), 0.74 (0.65-0.84), and 0.84 (0.77-0.90), respectively. Moreover, the risk of disability gradually decreased with participation in an increasing number of those leisure-time activities (P for trend <0.001). Frequent engagement in leisure-time activities was associated with a lower risk of disability among the Chinese oldest old. This study highlights the importance of incorporating a broad range of leisure-time activities into the daily lives of older adults.

Association between dietary diversity changes and frailty among Chinese older adults: findings from a nationwide cohort study.

BACKGROUND: Dietary diversity has been suggested as a potential preventive measure against frailty in older adults, but the effect of changes in dietary diversity on frailty is unclear. This study was conducted to examine the association between the dietary diversity score (DDS) and frailty among older Chinese adults. METHODS: A total of 12,457 adults aged 65 years or older were enrolled from three consecutive and nonoverlapping cohorts from the Chinese Longitudinal Healthy Longevity Survey (the 2002 cohort, the 2005 cohort, and the 2008 cohort). DDS was calculated based on nine predefined food groups, and DDS changes were assessed by comparing scores at baseline and the first follow-up survey. We used 39 self-reported health items to assess frailty. Cox proportional hazard models were performed to examine the association between DDS change patterns and frailty. RESULTS: Participants with low-to-low DDS had the highest frailty incidence (111.1/1000 person-years), while high-to-high DDS had the lowest (41.1/1000 person-years). Compared to the high-to-high group of overall DDS pattern, participants in other DDS change patterns had a higher risk of frailty (HRs ranged from 1.25 to 2.15). Similar associations were observed for plant-based and animal-based DDS. Compared to stable DDS changes, participants with an extreme decline in DDS had an increased risk of frailty, with HRs of 1.38 (1.24, 1.53), 1.31 (1.19, 1.44), and 1.29 (1.16, 1.43) for overall, plant-based, and animal-based DDS, respectively. CONCLUSIONS: Maintaining a lower DDS or having a large reduction in DDS was associated with a higher risk of frailty among Chinese older adults. These findings highlight the importance of improving a diverse diet across old age for preventing frailty in later life.

Blood mercury mediates the associations between fish consumption and serum uric acid levels among Chinese adults: A nationally representative study.

Fish consumption can increase purine load in human body, and the enrichment of mercury in fish may affect the glomerular filtration function, both resulting in increased serum uric acid (SUA) levels. The data of blood mercury (BHg), fish consumption frequency and SUA levels of 7653 participants aged 18 years or older was from China National Human Biomonitoring (2017-2018). The associations between fish consumption frequency, ln-transformed BHg and SUA levels were explored through weighted multiple linear regressions. The mediating effect of BHg levels between fish consumption frequency and SUA levels was evaluated by mediation analysis. We found that both the fish consumption frequency and BHg were positively associated with SUA levels in both sexes. Compared to participants who had never consumed fish, participants who consumed fish once a week or more had higher SUA levels [ß (95% confidence interval, CI): 20.39 (2.16, 38.62) in males; ß (95% CI): 10.06 (0.76, 19.37) in females] and ln-transformed BHg [ß (95% CI): 0.97 (0.61, 1.34) in males; ß (95% CI): 0.84 (0.63, 1.05) in females]. Each 1-unit increase in ln-transformed BHg, the SUA levels rose by 4.78 (95% CI: 0.01, 9.54) µmol/L for males and 3.81 (95% CI: 1.60, 6.03) µmol/L for females. The association between fish consumption with SUA levels was mediated by ln-transformed BHg with the percent mediated of 34.66% in males and 26.58% in females. It revealed that BHg played mediating roles in the elevation of SUA levels caused by fish consumption. This study's findings could promote the government to intervene in mercury pollution in fish, so as to ensure the safety of fish consumption.

Associations of Serum Per- and Polyfluoroalkyl Substances with Hyperuricemia in Adults: A Nationwide Cross-Sectional Study.

There has been widespread concern about the health hazards of per- and polyfluoroalkyl substances (PFAS), which may be the risk factor for hyperuricemia with evidence still insufficient in the general population in China. Here, we conducted a nationwide study involving 9,580 adults aged 18 years or older from 2017 to 2018, measured serum concentrations of uric acid and PFAS (PFOA, PFOS, 6:2 Cl-PFESA, PFNA, PFHxS) in participants, to assess the associations of individual PFAS with hyperuricemia, and estimated a joint effect of PFAS mixtures. We found positive associations of higher serum PFAS with elevated odds of hyperuricemia in Chinese adults, with the greatest contribution from PFOA (69.37%). The nonmonotonic dose-response (NMDR) relationships were observed for 6:2 Cl-PFESA and PFHxS with hyperuricemia. Participants with less marine fish consumption, overweight, and obesity may be the sensitive groups to the effects of PFAS on hyperuricemia. We highlight the potential health hazards of legacy long-chain PFAS (PFOA) once again because of the higher weights of joint effects. This study also provides more evidence about the NMDR relationships in PFAS with hyperuricemia and emphasizes a theoretical basis for public health planning to reduce the health hazards of PFAS in sensitive groups.

Analysis of changes in social isolation, loneliness, or both, and subsequent cognitive function among older adults: Findings from a nationwide cohort study.

INTRODUCTION: The study aimed to investigate the associations of changes in social isolation, loneliness, or both, with cognitive function. METHODS: Data were from 7299 older adults in the Chinese Longitudinal Healthy Longevity Survey. We defined four change patterns (no, incident, transient, and persistent) for social isolation and loneliness, and created nine-category variable to represent the joint changes. Tobit regression models and Cox models were performed. RESULTS: Incident, transient, and persistent social isolation or loneliness may accelerate cognitive decline (p < 0.05). Incident, transient, and persistent social isolation were associated with higher cognitive impairment risk, while only persistent loneliness was associated with higher cognitive impairment risk (p < 0.001). Notably, short-term or persistent social isolation was associated with accelerated cognitive decline and incident cognitive impairment, regardless of different loneliness change status (p < 0.05). DISCUSSION: Short-term or persistent social isolation and persistent loneliness may be a salient risk factor for cognitive decline and cognitive impairment. HIGHLIGHTS: Incident, transient, and persistent social isolation were associated with accelerated cognitive decline and higher cognitive impairment risk. Persistent loneliness was associated with accelerated cognitive decline and higher cognitive impairment risk. Short-term or persistent social isolation with concurrent different loneliness change status accelerated cognitive decline and higher cognitive impairment risk.

Healthy Lifestyle and the Likelihood of Becoming a Centenarian.

Importance: Previous studies have reported that lifestyle factors were associated with life expectancy and/or mortality, but most of them studied the middle-aged or older age groups (aged ≥60 years), and few focused on people aged 80 years or older. Objectives: To examine healthy lifestyle and the likelihood of becoming centenarians among people aged 80 years or older in China. Design, Settings, and Participants: Using data from the Chinese Longitudinal Healthy Longevity Survey, a nationally representative and one of the largest prospective cohorts targeting people aged 80 years or older established in 1998, a community-based, prospective nested case-control study was performed. Data were analyzed from December 1, 2022, to April 15, 2024. Exposures: A healthy lifestyle score for 100 (HLS-100, ranging from 0 to 6), including smoking, exercise, and dietary diversity, was constructed, with higher scores indicating potentially better health outcomes. Main Outcomes and Measures: The primary outcome was survivorship to becoming a centenarian by 2018 (the end of follow-up). Information on sociodemographic characteristics, lifestyle factors, and other covariates was collected. Results: The sample comprised 5222 individuals (61.7% women, mean [SD] age, 94.3 [3.3] years), including 1454 identified centenarians and 3768 controls (died before becoming centenarians) matched by age, sex, and year of entry. During a median follow-up of 5 (IQR, 3-7) years, 373 of 1486 individuals among the lowest HLS-100 (0-2) group and 276 of 851 individuals among the highest HLS-100 (5-6) group became centenarians. The adjusted odds ratio (AOR) comparing the highest vs the lowest HLS-100 groups was 1.61 (95% CI, 1.32-1.96; P < .001 for trend). An association was noted when we further treated centenarians with relatively healthy status as the outcome, as evaluated by self-reported chronic conditions, physical and cognitive function, and mental wellness (AOR, 1.54; 95% CI, 1.05-2.26). Similar results were observed in other sensitivity analyses. Conclusions and Relevance: In this case-control study of Chinese older adults, adhering to a healthy lifestyle appears to be important even at late ages, suggesting that constructing strategic plans to improve lifestyle behaviors among all older adults may play a key role in promoting healthy aging and longevity.

Positive Associations of Perfluoroalkyl and Polyfluoroalkyl Substances With Hypertension May Be Attenuated by Endogenous Sex Hormones: A Nationally Representative Cross-Sectional Study.

BACKGROUND: Perfluoroalkyl and polyfluoroalkyl substance (PFAS) has endocrine-disrupting properties and may affect blood pressure. Endogenous hormones also play a crucial role in the progression of hypertension. However, their interaction with hypertension remains to be explored. METHODS: This study included 10 794 adults aged ≥18 years from the China National Human Biomonitoring program. Weighted multiple logistic regression and linear regression were used to examine the associations of serum PFAS with hypertension, diastolic blood pressure, and systolic blood pressure. Joint effects of PFAS mixtures on hypertension, diastolic blood pressure, and systolic blood pressure were evaluated using quantile-based g-computation. Additive and multiplicative interactions were used to assess the role of PFAS with testosterone and estradiol on hypertension. RESULTS: The prevalence of hypertension in Chinese adults was 35.50%. Comparing the fourth quartile with the first quartile, odds ratio (95% CI) of hypertension were 1.53 (1.13-2.09) for perfluorononanoic acid, 1.40 (1.03-1.91) for perfluorodecanoic acid, 1.34 (1.02-1.78) for perfluoroheptane sulfonic acid, and 1.46 (1.07-1.99) for perfluorooctane sulfonic acid. Moreover, PFAS mixtures, with perfluorononanoic acid contributing the most, were positively associated with hypertension, diastolic blood pressure, and systolic blood pressure. PFAS and endogenous hormones had an antagonistic interaction in hypertension. For example, the relative excess risk ratio, attributable proportion, and synergy index for perfluorononanoic acid and estradiol were -3.61 (-4.68 to -2.53), -1.65 (-2.59 to -0.71), and 0.25 (0.13-0.47), respectively. CONCLUSIONS: Perfluorononanoic acid, perfluorodecanoic acid, perfluoroheptane sulfonic acid, perfluorooctane sulfonic acid, and PFAS mixtures showed positive associations with hypertension, systolic blood pressure, and diastolic blood pressure. Positive associations of PFAS with hypertension might be attenuated by increased levels of endogenous sex hormones.

Metabolic obesity phenotypes and all-cause mortality among the Chinese oldest-old population: a prospective cohort study.

BACKGROUND: The obesity paradox has been reported among older adults. However, whether the favorable effect of obesity is dependent on metabolic status remains largely unknown. We aimed to explore the association of metabolic obesity phenotypes and their changes with all-cause mortality among the Chinese oldest-old population. METHODS: This prospective cohort study included 1207 Chinese oldest old (mean age: 91.8 years). Metabolic obesity phenotypes were determined by central obesity and metabolic status, and participants were classified into metabolically healthy obesity (MHO), metabolically unhealthy obesity (MUO), metabolically healthy non-obesity (MHN), and metabolically unhealthy non-obesity (MUN). The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated by Cox regression models. RESULTS: During 5.3 years of follow-up, 640 deaths were documented. Compared with non-obesity, obesity was associated with a decreased mortality risk among participants with metabolically healthy (HR, 0.75; 95% CI, 0.63-0.91) while this association was insignificant among metabolically unhealthy. Compared to MHO, MHN (HR, 1.27; 95% CI, 1.06-1.53) and MUN (HR, 1.49; 95% CI, 1.10-2.02) were significantly associated with an increased mortality risk. Compared to those with stable MHO, those transited from MHO to MUO demonstrated a higher mortality risk (HR, 1.81; 95% CI, 1.06-3.11). CONCLUSIONS: MHO predicts better survival among the Chinese oldest-old population. These findings suggest that ensuring optimal management of metabolic health is beneficial and taking caution in weight loss based on the individual body weight for the metabolically healthy oldest-old adults.

Associations between socioeconomic status and rates of blood pressure changes among Chinese older adults: a longitudinal community-based cohort study.

OBJECTIVES: The relationships between socioeconomic status (SES) and blood pressure changes among older adults in China remain unclear. This study aimed to examine the associations between SES and rates of blood pressure changes among Chinese older adults. STUDY DESIGN: Community-based, prospective, longitudinal cohort study. METHODS: This study included 13,541 participants aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey between 2002 and 2018. SES was assessed by educational level, occupation, household yearly per capita income, and financial support. The estimated annual changes (EACs) of blood pressure were computed as the difference in blood pressure levels between any two adjacent surveys divided by the time interval. Associations between SES and EACs of blood pressure were evaluated using generalised estimating equations. RESULTS: Lower SES was significantly associated with greater annual increases of blood pressure among Chinese older adults. The effect of SES on EACs of blood pressure was more pronounced among non-hypertensive participants. Compared to EACs among non-hypertensive participants with high SES, multivariable-adjusted EACs among those with low SES increased by 0.57 mmHg (95% confidence interval [CI]: 0.16, 0.99), 0.32 mmHg (95% CI: 0.07, 0.57), and 0.40 mmHg (95% CI: 0.13, 0.66) for systolic blood pressure, diastolic blood pressure, and mean arterial pressure, respectively. CONCLUSIONS: This study revealed strong associations between SES and EACs of blood pressure among Chinese older adults, especially in the non-hypertensive population. Findings suggest that prevention strategies for hypertension should pay more attention to the older population with low SES.

Dietary seafood as a potential modifier in the relationship between per- and polyfluoroalkyl substances (PFASs) burden and prediabetes/diabetes: Insights from a nationally representative cross-sectional study.

While seafood is recognized for its beneficial effects on glycemic control, concerns over elevated levels of per- and polyfluoroalkyl substances (PFASs) may deter individuals from its consumption. This study aims to elucidate the relationship between seafood intake, PFASs exposure, and the odds of diabetes. Drawing from the China National Human Biomonitoring data (2017-2018), we assessed the impact of PFASs on the prevalence of prediabetes and diabetes across 10851 adults, including 5253 individuals (48.1%) reporting seafood consumption. Notably, seafood consumers exhibited PFASs levels nearly double those of non-consumers. Multinomial logistic regression identified significant positive associations between serum PFASs concentrations and prediabetes (T3 vs. T1: ORPFOA: 1.64 [1.08-2.49], ORPFNA: 1.59 [1.19-2.13], ORPFDA: 1.56 [1.13-2.17], ORPFHxS: 1.58 [1.18-2.12], ORPFHpS: 1.73 [1.24-2.43], ORPFOS: 1.51 [1.15-1.96], OR6:2 Cl-PFESA: 1.58 [1.21-2.07]). Significant positive association were also found between PFHpS, PFOS, and diabetes. RCS curves indicated significant non-linear relationships between log-transformed PFOA, PFUnDA, PFOS, 6:2 Cl-PFESA, and FBG levels. Subgroup analyses revealed that seafood consumption significantly mitigated the associations between PFASs burdens and prediabetes/diabetes. These findings suggest a protective role of dietary seafood against the adverse effects of PFASs exposure on glycemic disorders, offering insights for dietary interventions aimed at mitigating diabetes risks associated with PFASs.

Body mass index, waist circumference, and mortality in subjects older than 80 years: a Mendelian randomization study.

BACKGROUND AND AIMS: Emerging evidence has raised an obesity paradox in observational studies of body mass index (BMI) and health among the oldest-old (aged ≥80 years), as an inverse relationship of BMI with mortality was reported. This study was to investigate the causal associations of BMI, waist circumference (WC), or both with mortality in the oldest-old people in China. METHODS: A total of 5306 community-based oldest-old (mean age 90.6 years) were enrolled in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) between 1998 and 2018. Genetic risk scores were constructed from 58 single-nucleotide polymorphisms (SNPs) associated with BMI and 49 SNPs associated with WC to subsequently derive causal estimates for Mendelian randomization (MR) models. One-sample linear MR along with non-linear MR analyses were performed to explore the associations of genetically predicted BMI, WC, and their joint effect with all-cause mortality, cardiovascular disease (CVD) mortality, and non-CVD mortality. RESULTS: During 24 337 person-years of follow-up, 3766 deaths were documented. In observational analyses, higher BMI and WC were both associated with decreased mortality risk [hazard ratio (HR) 0.963, 95% confidence interval (CI) 0.955-0.971 for a 1-kg/m2 increment of BMI and HR 0.971 (95% CI 0.950-0.993) for each 5 cm increase of WC]. Linear MR models indicated that each 1 kg/m2 increase in genetically predicted BMI was monotonically associated with a 4.5% decrease in all-cause mortality risk [HR 0.955 (95% CI 0.928-0.983)]. Non-linear curves showed the lowest mortality risk at the BMI of around 28.0 kg/m2, suggesting that optimal BMI for the oldest-old may be around overweight or mild obesity. Positive monotonic causal associations were observed between WC and all-cause mortality [HR 1.108 (95% CI 1.036-1.185) per 5 cm increase], CVD mortality [HR 1.193 (95% CI 1.064-1.337)], and non-CVD mortality [HR 1.110 (95% CI 1.016-1.212)]. The joint effect analyses indicated that the lowest risk was observed among those with higher BMI and lower WC. CONCLUSIONS: Among the oldest-old, opposite causal associations of BMI and WC with mortality were observed, and a body figure with higher BMI and lower WC could substantially decrease the mortality risk. Guidelines for the weight management should be cautiously designed and implemented among the oldest-old people, considering distinct roles of BMI and WC.

Associations of environmental cadmium exposure with kidney damage: Exploring mediating DNA methylation sites in Chinese adults.

Environmental exposure is widely recognized as the primary sources of Cadmium (Cd) in the human body, and exposure to Cd is associated with kidney damage in adults. Nevertheless, the role of DNA methylation in Cd-induced kidney damage remains unclear. This study aimed to investigate the epigenome-wide association of environmental Cd-related DNA methylation changes with kidney damage. We included 300 non-smoking adults from the China in 2019. DNA methylation profiles were measured with Illumina Infinium MethylationEPIC BeadChip array. Linear mixed-effect model was employed to estimate the effects of urinary Cd with DNA methylation. Differentially methylated positions (DMPs) associated with urinary Cd were then tested for the association with kidney damage indicators. The mediation analysis was further applied to explore the potential DNA methylation based mediators. The prediction model was developed using a logistic regression model, and used 1000 bootstrap resampling for the internal validation. We identified 27 Cd-related DMPs mapped to 20 genes after the adjustment of false-discovery-rate for multiple testing among non-smoking adults. 17 DMPs were found to be associated with both urinary Cd and kidney damage, and 14 of these DMPs were newly identified within the Chinese. Mediation analysis revealed that DNA methylation of cg26907612 and cg16848624 mediated the Cd-related reduced kidney damage. In addition, ten variables were selected using the LASSO regression analysis and were utilized to develop the prediction model. It found that the nomogram model predicted the risk of kidney damage caused by environmental Cd with a corrected C-index of 0.779. Our findings revealed novel DMPs associated with both environmental Cd exposure and kidney damage among non-smoking adults, and developed an easy-to-use nomogram-illustrated model using these novel DMPs. These findings could provide a theoretical basis for formulating prevention and control strategies for kidney damage from the perspective of environmental pollution and epigenetic regulation.

Associations of low-density lipoprotein cholesterol with all-cause and cause-specific mortality in older adults in China.

CONTEXT: Limited information was available on detailed associations of low-density lipoprotein cholesterol (LDL-C) with all-cause and cause-specific mortality in older adults. METHODS: This prospective cohort study included a representative sample of 211,290 adults aged 65 or older, who participated in Shenzhen Healthy Aging Research 2018-2019. The vital status of the participants by 31 December, 2021 was determined. We estimated the hazard ratios (HR) with 95% confidence intervals for all-cause or cause-specific mortality using multivariable Cox proportional hazards models and Cox models with restricted cubic spline(RCS) . RESULTS: The median follow-up time was 3.08 years. A total of 5,333 participants were confirmed to have died. Among them, 2,303 cardiovascular disease (CVD) deaths and 1,881 cancer deaths occurred. Compared to those with LDL-C of 100-129 mg/dL, the all-cause mortality risk was significantly higher for individuals with LDL-C level that was very low (< 70 mg/dL) or low (70-99 mg/dL). Compared with individuals with the reference LDL-C level, the multivariable-adjusted HR for CVD-specific mortality was 1.327 for those with very low LDL-C level (< 70 mg/dL), 1.437 for those with high LDL-C level (160 mg/dL ≦ LDL-C < 190mg/dL), 1.528 for those with very high LDL-C level (≥ 190 mg/dL). Low LDL-C level (70-99 mg/dL) and very low LDL-C level (< 70 mg/dL) were also associated with increased cancer mortality and other-cause mortality, respectively. The results from RCS curve showed similar results. CONCLUSION: Considering the risk of all-causes mortality and cause-specific mortality, we recommended 100-159 mg/dL as the optimal range of LDL-C among older adults in China.

Associations between serum per- and polyfluoroalkyl substances and thyroid hormones in Chinese adults: A nationally representative cross-sectional study.

Disruption of thyroid homeostasis has been indicated in human studies on the effects of per- and polyfluoroalkyl substances (PFASs). However, limited research exists on this topic within the general Chinese population. Based on a substantial and representative sample of the Chinese adult population, our study provides insight into how PFASs specifically affect thyroid homeostasis. The study included 10 853 participants, aged 18 years and above, sampled from nationally representative data provided by the China National Human Biomonitoring (CNHBM). Weighted multiple linear regression and restricted cubic spline (RCS) models were used to explore the associations between eight individual PFAS concentrations and total thyroxine (T4), total triiodothyronine (T3), and the T4/T3 ratio. Bayesian kernel machine regression (BKMR) and quantile-based g-computation (qgcomp) were employed to explore the joint and independent effects of PFASs on thyroid homeostasis. Both individual PFASs and PFAS mixtures exhibited a significant inverse association with serum T3 and T4 levels, and displayed a positive association with the T4/T3 ratio. Perfluoroundecanoic acid (PFUnDA) [-0.07 (95 % confidence interval (CI): -0.08, -0.05)] exhibited the largest change in T3 level. PFUnDA also exhibited a higher weight compared to other PFAS compounds in qgcomp models. Additionally, a critical exposure threshold for each PFAS was identified based on nonlinear dose-response associations; beyond these thresholds, the decreases in T3 and T4 levels plateaued. Specifically, for perfluoroheptane sulfonic acid (PFHpS) and 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA), an initial decline in hormone levels was observed, followed by a slight increase when concentrations surpassed 0.7 ng/mL and 2.5 ng/mL, respectively. Sex-specific effects were more pronounced in females, and significant associations were observed predominantly in younger age groups. These insights contribute to our understanding of how PFAS compounds impact thyroid health and emphasize the need for further research and environmental management measures to address these complexities.

Serum 25-Hydroxyvitamin D and Risk of Disability in Activities of Daily Living among the Oldest-Old: An Observational and Mendelian Randomization Study.

BACKGROUND: Vitamin D deficiency and disability are both prevalent among older adults. However, the association between them has rarely been investigated in the oldest-old subjects (aged ≥80 y), and the causality remains unclear. OBJECTIVE: This study aimed to elucidate the causal effect of vitamin D on the incident risk of disability in activities of daily living (ADL) among Chinese oldest-old based on the 2012-2018 Chinese Healthy Ageing and Biomarkers Cohort Study. METHODS: Serum 25-hydroxyvitamin D [25(OH)D] concentrations and ADL status at baseline and follow-up interviews were documented. Cox regression models were applied among 1427 oldest-old (mean age, 91.2 y) with normal baseline ADL status. One sample Mendelian randomization (MR) analyses were performed on a subset of 941 participants with qualified genetic data, using a 25(OH)D-associated genetic risk score as the genetic instrument. RESULTS: During a median follow-up of 3.4 y, 231 participants developed disability in ADL. Serum 25(OH)D concentration was inversely associated with the risk of disability in ADL [per 10 nmol/L increase hazard ratio (HR) 0.85; 95% CI: 0.75, 0.96]. Consistent results from MR analyses showed that a 10 nmol/L increment in genetically predicted 25(OH)D concentration corresponded to a 20% reduced risk of ADL disability (HR 0.80; 95% CI: 0.68, 0.94). Nonlinear MR demonstrated a monotonic declining curve, with the HRs exhibiting a more pronounced reduction among individuals with 25(OH)D concentrations below 50 nmol/L. Subgroup analyses showed that the associations were more distinct among females and those with poorer health conditions. CONCLUSIONS: Our study supports an inverse causal relationship between serum 25(OH)D concentration and the risk of disability in ADL among Chinese oldest-old. This protective effect was more distinct, especially for participants with vitamin D deficiency. Appropriate measures for improving vitamin D might help reduce the incidence of physical disability in this specific age group.

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.

Mediating Role of Liver Dysfunction in the Association between Arsenic Exposure and Diabetes in Chinese Adults: A Nationwide Cross-Sectional Study of China National Human Biomonitoring (CNHBM) 2017-2018.

Inconsistent results have been reported regarding the association between low-to-moderate arsenic (As) exposure and diabetes. The effect of liver dysfunction on As-induced diabetes remains unclear. The cross-sectional study included 10,574 adults from 2017-2018 China National Human Biomonitoring. Urinary total As (TAs) levels were analyzed as markers of As exposure. Generalized linear mixed models and restricted cubic splines models were used to examine the relationships among TAs levels, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentrations, and diabetes prevalence. Mediating analysis was performed to assess whether liver dysfunction mediated the association between TAs and diabetes. Overall, the OR (95% CI) of diabetes in participants in the second, third, and fourth quartiles of TAs were 1.08 (0.88, 1.33), 1.17 (0.94, 1.45), and 1.52 (1.22, 1.90), respectively, in the fully adjusted models compared with those in the lowest quartile. Serum ALT was positively associated with TAs and diabetes. Additionally, mediation analyses showed that ALT mediated 4.32% of the association between TAs and diabetes in the overall population and 8.86% in the population without alcohol consumption in the past year. This study suggested that alleviating the hepatotoxicity of As could have implications for both diabetes and liver disease.

China's public health initiatives for climate change adaptation.

China's health gains over the past decades face potential reversals if climate change adaptation is not prioritized. China's temperature rise surpasses the global average due to urban heat islands and ecological changes, and demands urgent actions to safeguard public health. Effective adaptation need to consider China's urbanization trends, underlying non-communicable diseases, an aging population, and future pandemic threats. Climate change adaptation initiatives and strategies include urban green space, healthy indoor environments, spatial planning for cities, advance location-specific early warning systems for extreme weather events, and a holistic approach for linking carbon neutrality to health co-benefits. Innovation and technology uptake is a crucial opportunity. China's successful climate adaptation can foster international collaboration regionally and beyond.