Long-term exposure to PM2.5 chemical constituents and diabesity: evidence from a multi-center cohort study in China.

Background: Long-term exposure to PM2.5 is known to increase the risks for diabetes and obesity, but its effects on their coexistence, termed diabesity, remain uncertain. This study aimed to investigate the associations of long-term exposure to PM2.5 and its chemical constituents with the risks for diabesity, diabetes, and obesity. Methods: This cross-sectional study used the baseline data of a multi-center cohort, consisting of three provincially representative cohorts comprising a total of 134,403 participants from the eastern (Fujian Province), central (Hubei Province), and western (Yunnan Province) regions of China. Obesity and diabetes, and diabesity were identified by a body mass index (BMI) ≥28 kg/m2 and fasting plasma glucose (FPG) ≥126 mg/dL. The average concentrations of PM2.5 and five chemical constituents (NO3 -, SO4 2-, NH4 +, organic matter, and black carbon) over participants' residence during the past three years were estimated using machine learning models. Logistic regression models with double robust estimators, Bayesian kernel machine regression, and weighted quantile sum regression were employed to estimate independent and joint effects of PM2.5 chemical constituents on the risks for diabesity, diabetes, and obesity, as well as the differences from the effects on obesity. Stratified analyses were performed to examine effect modification of sociodemographic and lifestyle factors. Findings: There were 129,244 participants with a mean age of 54.1 ± 13.8 years included in the study. Each interquartile range increase in PM2.5 concentration (8.53 µg/m3) was associated with an increased risk for diabesity (OR = 1.23 [1.17, 1.30]), diabetes only (OR = 1.16 [1.13, 1.19]), and obesity only (OR = 1.03 [1.00, 1.05]). Long-term exposure to each PM2.5 chemical constituent was associated with an increased risk for diabesity, where organic matter exposure, with maximum weight (48%), was associated with a higher risk for diabesity (OR = 1.21 [1.16, 1.27]). Among those with obesity, black carbon contributed most (68%) to the joint effect of PM2.5 chemical constituents on diabesity (OR = 1.16 [1.11, 1.22]). Physical activity reduced adverse effects of PM2.5 on diabesity. Also, additive rather than multiplicative effects of obesity on the PM2.5-diabetes association were observed. Interpretation: Long-term exposure to PM2.5 and its chemical constituents was associated with an increased risk for diabesity, stronger than associations for diabetes and obesity alone. The main constituents associated with diabesity and obesity were black carbon and organic matter. Funding: National Natural Science Foundation of China (42271433, 723B2017), National Key R&D Program of China (2023YFC3604702), Fundamental Research Funds for the Central Universities (2042023kfyq04, 2042024kf1024), the Science and Technology Major Project of Tibetan Autonomous Region of China (XZ202201ZD0001G), Science and technology project of Tibet Autonomous Region（XZ202303ZY0007G), Key R&D Project of Sichuan Province (2023YFS0251), Renmin Hospital of Wuhan University (JCRCYG-2022-003), Jiangxi Provincial 03 Special Foundation and 5G Program (20224ABC03A05), Wuhan University Specific Fund for Major School-level Internationalization Initiatives (WHU-GJZDZX-PT07).

Disability level's impact on blood pressure-mortality association in older long-term care adults: evidence from a large Chinese cohort study.

BACKGROUND: Evidence of the optimal blood pressure (BP) target for older adults with disability in long-term care is limited. We aim to analyze the associations of BP with mortality in older adults in long-term care setting with different levels of disability. METHODS: This prospective cohort study was based on the government-led long-term care programme in Chengdu, China, including 41,004 consecutive disabled adults aged ≥ 60 years. BP was measured during the baseline survey by trained medical personnel using electronic sphygmomanometers. Disability profile was assessed using the Barthel index. The association between blood pressure and mortality was analyzed with doubly robust estimation, which combined exposure model by inverse probability weighting and outcome model fitted with Cox regression. The non-linearity was examined by restricted cubic spline. The primary endpoint was all-cause mortality, and the secondary endpoints were cardiovascular and non-cardiovascular mortality. RESULTS: The associations between systolic blood pressure (SBP) and all-cause mortality were close to a U-shaped curve in mild-moderate disability group (Barthel index ≥ 40), and a reversed J-shaped in severe disability group (Barthel index < 40). In mild-moderate disability group, SBP < 135 mmHg was associated with elevated all-cause mortality risks (HR 1.21, 95% CI, 1.10-1.33), compared to SBP between 135 and 150 mmHg. In severe disability group, SBP < 150 mmHg increased all-cause mortality risks (HR 1.21, 95% CI, 1.16-1.27), compared to SBP between 150 and 170 mmHg. The associations were robust in subgroup analyses in terms of age, gender, cardiovascular comorbidity and antihypertensive treatment. Diastolic blood pressure (DBP) < 67 mmHg (HR 1.29, 95% CI, 1.18-1.42) in mild-moderate disability group and < 79 mmHg (HR 1.15, 95% CI, 1.11-1.20) in severe disability group both demonstrated an increased all-cause mortality risk. CONCLUSION: The optimal SBP range was found to be higher in older individuals in long-term care with severe disability (150-170mmHg) compared to those with mild to moderate disability (135-150mmHg). This study provides new evidence that antihypertensive treatment should be administered cautiously in severe disability group in long-term care setting. Additionally, assessment of disability using the Barthel index can serve as a valuable tool in customizing the optimal BP management strategy. TRIAL REGISTRATION: Chinese Clinical Trial Registry (Registration Number: ChiCTR2100049973).

Relationship of long-term exposure to air pollutant mixture with metabolic-associated fatty liver disease and subtypes: A retrospective cohort study of the employed population of Southwest China.

BACKGROUND: While evidence suggests that PM2.5 is associated with overall prevalence of Metabolic (dysfunction)-Associated Fatty Liver Disease (MAFLD), effects of comprehensive air pollutant mixture on MAFLD and its subtypes remain unclear. OBJECTIVE: To investigate individual and joint effects of long-term exposure to comprehensive air pollutant mixture on MAFLD and its subtypes. METHODS: Data of 27,699 participants of the Chinese Cohort of Working Adults were analyzed. MAFLD and subtypes, including overweight/obesity, lean, and diabetes MAFLD, were diagnosed according to clinical guidelines. Concentrations of NO3-, SO42-, NH4+, organic matter (OM), black carbon (BC), PM2.5, SO2, NO2, O3 and CO were estimated as a weighted average over participants' residential and work addresses for the three years preceding outcome assessment. Logistic regression and weighted quantile sum regression were used to estimate individual and joint effects of air pollutant mixture on presence of MAFLD. RESULTS: Overall prevalence of MAFLD was 26.6 % with overweight/obesity, lean, and diabetes MAFLD accounting for 92.0 %, 6.4 %, and 1.6 %, respectively. Exposure to SO42-, NO3-, NH4+, BC, PM2.5, NO2, O3and CO was significantly associated with overall MAFLD, overweight/obesity MAFLD, or lean MAFLD in single pollutant models. Joint effects of air pollutant mixture were observed for overall MAFLD (OR = 1.10 [95 % CI: 1.03, 1.17]), overweight/obesity (1.09 [1.02, 1.15]), and lean MAFLD (1.63 [1.28, 2.07]). Contributions of individual air pollutants to joint effects were dominated by CO in overall and overweight/obesity MAFLD (Weights were 42.31 % and 45.87 %, respectively), while SO42- (36.34 %), SO2 (21.00 %) and BC (12.38 %) were more important in lean MAFLD. Being male, aged above 45 years and smoking increased joint effects of air pollutant mixture on overall MAFLD. CONCLUSIONS: Air pollutant mixture was associated with MAFLD, particularly the lean MAFLD subtype. CO played a pivotal role in both overall and overweight/obesity MAFLD, whereas SO42- were associated with lean MAFLD.

Mortality risk of people living with HIV under hypothetical intervention scenarios of PM2.5 and HIV severity: a prospective cohort study.

This study estimated and compared mortality risks among people living with HIV (PLWH) under the real-world and hypothetical scenarios of PM2.5 concentrations and HIV severity. An open cohort from all PLWH receiving antiretroviral therapy in Sichuan during 2010-2019 was constructed, resulting in 541,515 person-years. Annual mean concentrations of PM2.5 were estimated and linked to PLWH by their residential address. The parametric g-formula were used to assess 3- and 5-year mortality risks under the real-world and hypothetical scenarios of PM2.5 (10-35, 35-50, 50-75 µg/m3) and CD4 concentrations (0-200, 200-500, 500-800, 800-1100 counts/µl). The estimated 3- and 5-year mortality risks among the PLWH were 14.43 % and 19.38 %, respectively, which would decrease substantially when annual PM2.5 concentration were reduced to between 10 and 35 µg/m3 (risk difference [RD] = -3.23 % and - 4.06 %) and would increase when PM2.5 concentration were elevated to between 50 and 75 µg/m3 (RD = 3.59 % and 5.04 %). The mortality risk would increase when CD4 concentration were reduced to <200 counts/µl (RD = 15.90 % and 20.27 %) and would decrease when CD4 concentration were ≥ 200 counts/µl, especially to between 800 and 1100 counts/µl (RD = -9.01 % and - 11.75 %). The elevated concentration of PM2.5 may disproportionately affect individuals with immune deficiency, especially those with more severity. The findings would serve as justifications for future intervention design and policy making to alleviate air pollution and improve environmental justice and health equity.

Toward a Prognostic Model for Mortality Risk in Older People Living With HIV: A Prospective Cohort Study From Southwestern China.

OBJECTIVE: The existing prognostic models for mortality risk in people living with HIV (PLWH) may not be applicable for older PLWH because the risk factors were confined to biomarkers and clinical variables. We developed and validated a nomogram for the prognosis of all-cause mortality in older PLWH based on comprehensive predictors. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: We included 824 participants aged ≥50 years (mean age, 64.0 ± 7.6 years) from 30 study sites in Sichuan, China, and followed up from Nov 2018 to Mar 2021. METHODS: Data on demographics, biomarkers, and clinical indicators were extracted from the registry; mental and social factors were assessed by a survey. Elastic net was used to select predictors. A nomogram was developed based on Cox proportional hazards regression model to visualize the relative effect size (points) of the selected predictors. The prognostic index (PI) was calculated by summing points of all predictors to quantify mortality risk. RESULTS: Predictive performance of PI from the nomogram was good, with area under the curve of 0.76 for the training set, and 0.77 for the validation set. Change in CD4 count, virological failure in antiretroviral therapy, and living with comorbidities were robust predictors. Depressive symptoms were an important predictor in men, those aged ≥65 years, and those with time of diagnosis <1 year; low social capital was an additional predictor in people aged <65. Mortality risk increased approximately 10-fold among participants whose PI was in the fourth quartile compared with those in the first quartile (hazard ratio, 9.5; 95% CI, 2.9-31.5). CONCLUSION AND IMPLICATIONS: Although biological and clinical factors are crucial predictors, mental and social predictors are essential for specific groups. The developed nomogram is useful for identifying risk factors and groups at risk of mortality in older PLWH.

Long-term effects of PM2.5 constituents on metabolic syndrome and mediation effects of serum uric acid.

Exposure to particulate matter with aerodynamic diameter ≤2.5 µm (PM2.5) was associated with the risk for metabolic syndrome (MetS) in the general population, but the contributions of individual PM2.5 constituents to this association and the potential pathway between PM2.5 constituents and MetS risk are not well elaborated. This study aimed to investigate associations between PM2.5 constituents and MetS in general populations, relative importance of PM2.5 constituents to and mediation effects of serum uric acid (SUA) on those associations. The 48,148 participants from a provincially representative cohort established in southwest China were included. The 3-year average concentrations of PM2.5 and its constituents (nitrate [NO3-], sulfate [SO42-], ammonium [NH4+], organic matter [OM], and black carbon [BC]) were estimated using a series of machine-learning models. Multivariate logistic regression and weighted quantile sum regression were used to estimate effects of independent PM2.5 constituents on MetS and their contributions to the joint effect. Mediation analysis examined the potential mediation effects of SUA on the associations between PM2.5 constituents and MetS. Each interquartile range (IQR) increase in the concentration of PM2.5 constituents was all positively associated with the increased MetS odds, including SO42- (OR = 1.15 [1.11, 1.19]]), NO3- (OR = 1.12 [1.08, 1.16]), NH4+ (OR = 1.13 [1.09, 1.17]), OM (OR = 1.09 [1.06, 1.13]), and BC (OR = 1.09 [1.06, 1.13]). Their joint associations on MetS were mainly attributed to SO42- (weight=46.1%) and NH4+ (44.0%). The associations of PM2.5 constituents with abnormal MetS components were mainly attributed to NH4+ for elevated BP (51.6%) and reduced HDL-C (97.0%), SO42- for elevated FG (68.9%), NO3- for elevated TG (51.0%), and OM for elevated WC (63.0%). Percentages mediated by SUA for the associations of PM2.5, SO42-, NO3-, and BC with MetS were 13.6%, 13.1%, 10.6%, and 11.1%, respectively. Long-term exposure to PM2.5 constituents, mainly NH4+ and SO42-, was positively associated with MetS odds, partially mediated by SUA.

Network analysis of illness perception, stigma, and resilience with cognition in old people living with HIV.

OBJECTIVES: Old people living with HIV (PLWH) are highly susceptible to HIV-related psychological and neurocognitive disorders, which are multidimensional and inseparably intertwined. Despite this, few studies have investigated the interrelationship between these disorders. We aimed to estimate the detailed associations and identify potential intervention points between HIV-related psychological factors and cognitive function in old PLWH. METHODS: This cross-sectional study drew on the Older People with HIV Infections Cohort from 65 communities in Sichuan, China. Three HIV-related psychological factors, including illness perception, HIV stigma perception and resilience, were collected using a self-reported questionnaire. Cognitive function was measured using the MoCA-B scale. Network analysis was used to estimate the interrelationships between HIV-related psychological factors and cognitive function dimensions in old PLWH, and to identify factors that act as bridges in connecting these factors in the network. RESULTS: Of the 1587 old PLWH, 47.0% had mild or severe cognitive function impairment. Network analysis revealed that better visual perception was directly connected with poorer negative self-image (edge weight: 0.13), and poorer illness comprehensibility was connected with poor visual perception (-0.09) and executive functioning (-0.13). The cognitive illness perceptions (bridge strength: 0.41), illness comprehensibility (0.36) and negative self-image (0.39) were identified as bridges connecting HIV-related psychological and cognitive function. CONCLUSIONS: The interconnection of HIV-related illness perception, stigma perception, and resilience with cognition may be achieved through the links of negative self-image, illness comprehensibility and cognitive illness perceptions. These factors may serve as potential non-pharmaceutical action points to improve psychological and cognitive health among old PLWH.

Development and validation of an age-sex-ethnicity-specific metabolic syndrome score in the Chinese adults.

Metabolic syndrome (MetS) is characterized by metabolic dysfunctions and could predict future risk for cardiovascular diseases (CVDs). However, the traditionally defined dichotomous MetS neither reflected MetS severity nor considered demographic variations. Here we develop a continuous, age-sex-ethnicity-specific MetS score based on continuous measures of the five metabolic dysfunctions (waist circumference [WC], triglycerides [TG], high-density lipoprotein cholesterol [HDL-C], mean arterial pressure [MAP], and fasting blood glucose [FBG]). We find that the weights of metabolic dysfunctions in the score vary across age-sex-ethnicity-specific subgroups, with higher weights for TG, HDL-C, and WC. Each unit increase in the score is associated with increased risks for hyperlipidemia, diabetes, and hypertension, and elevated levels of HbA1c, cholesterol, body mass index, and serum uric acid. The score shows high sensitivity and accuracy for detecting CVD-related risk factors and is validated in different geographical regions. Our study would advance early identification of CVD risks and, more broadly, preventive medicine and sustainable development goals.

Association between chronotype and metabolic-associated fatty liver disease in employed adults: A longitudinal study in Southwestern China.

The circadian system is an essential physiological regulator of mammals, and sleep chronotype may be associated with the risk of metabolic disorders. However, evidence regarding the role of sleep chronotype in the development of metabolic-associated fatty liver disease (MAFLD) is scarce, particularly in employed adults. We conducted a longitudinal study of 1,309 employed adults in Southwestern China with a five-year follow-up from 2017 to 2021. MAFLD was assessed by the presence of hepatic steatosis using abdominal ultrasonography, overweight/obese status, diabetes mellitus, metabolic dysregulation, or elevation of high-sensitivity C-reactive protein. Chronotype was assessed by the Morning and Evening Questionnaire-5 (MEQ-5). The logistic random effects model was applied to analyze the 5-year panel data to estimate the association between chronotype and MAFLD, and the potential effect modification of demographics on such association. The MAFLD prevalence of participants was 38.6% at baseline and showed an increasing trend during follow-up (p for trends < 0.05). Compared with morning chronotype, evening chronotype was positively associated with MAFLD (OR = 2.19, 95%CI: [1.09, 4.40]) after controlled for covariates. Age, sex, ethnicity, and educational level did not modify the association between chronotype and MAFLD. These findings suggest that improving circadian rhythms could reduce the risk of MAFLD and chronic disease burden among employed adults.

Associations between long-term exposure to PM2.5 chemical constituents and allergic diseases: evidence from a large cohort study in China.

BACKGROUND: Exposure to air pollutants may cause immune responses and further allergic diseases, but existing studies have mostly, if not all, focused on effects of short-term exposure to PM2.5 on allergic diseases. OBJECTIVES: We estimated associations of long-term exposure to PM2.5 chemical constituents with allergic disease risks and effect modification. METHODS: We used the baseline of a newly established, provincially representative cohort of 51,480 participants in southwest China. The presence of allergic rhinitis, allergic asthma, urticaria, and allergic conjunctivitis was self-reported by following a formed questionnaire in face-to-face interviews. The average concentrations of PM2.5 chemical constituents (NO3-, SO42-, NH4+, organic matter [OM], and black carbon [BC]) over participants' residence were estimated using machine learning models. Logistic regression with double robust estimator and weighted quantile sum regression were used to estimate the effects of PM2.5 chemical constituents on allergic disease risks, as well as relative importance of each PM2.5 chemical constituent. RESULTS: Per interquartile range increase in the concentration of all PM2.5 chemical constituents was associated with the elevated risks for allergic asthma (OR = 1.79 [1.41-2.26]), allergic conjunctivitis (1.54 [1.19-2.00]), urticaria (1.36 [1.25-1.48]), and allergic rhinitis (1.18 [1.11-1.26]). NO3- contributed more to risks for allergic asthma (weight = 46.05 %), urticaria (72.29 %), and allergic conjunctivitis (47.65 %), while NH4+ contributed more to allergic rhinitis (78.07 %). OM contributed most to the risks for allergic asthma (30.81 %) and allergic conjunctivitis (31.40 %). BC was also associated with allergic rhinitis, urticaria, and allergic conjunctivitis, only with a considerable weight for urticaria (24.59 %). Joint effects of PM2.5 chemical constituents on risks for allergic rhinitis and urticaria were stronger in minorities and farmers than their counterparts. CONCLUSION: Long-term exposure to PM2.5 chemical constituents was associated with the increased allergic disease risks, with NO3- and NH4+ accounting for the largest variance of the associations. Our findings would serve as scientific evidence for developing more explicit strategies of air pollution control.

Influences of long-term care insurance on pulmonary and urinary tract infections among older people with disability.

BACKGROUND: Pulmonary infection (PI) and urinary tract infection (UTI) have been the most common cause of hospitalization and most frequent infection respectively in older people with disability (OPWD). Long-term care insurance (LTCI) policy, intending to provide services to reduce the disease burden of OPWD, it remains unclear whether LTCI could reduce PI-, and UTI-related hospitalizations. This quasi-experimental study aimed to assess the influences of LTCI on all-cause, especially PI- and UTI-related hospitalizations among OPWD and the variation across sociodemographic characteristics. METHODS: 32,120 participants in the Chengdu Long-term Care Insurance cohort were considered the intervention group, and 2,704 not covered by the LTCI were in the control group. A total of 3,134,160 hospitalization records were collected between January 2014 and June 2021. A doubly robust difference-in-differences (DID) method was used to estimate the average treatment effect on the treated (ATT), indicating the average effect of LTCI on intervention group. RESULTS: The average monthly all-cause, PI-, and UTI-related hospitalization rates were 16.3%, 4.0% and 0.5% in the intervention group, respectively, and were 19.3%, 3.9% and 0.5% in the control group, respectively. Under LTCI, all-cause (ATT [95% CI]: 7.15% [6.41%, 7.88%]), PI- (3.25% [2.76%, 3.74%]), and UTI-related hospitalizations (0.46% [0.28%, 0.64%]) were decreased. The influences of LTCI became significant after 5 months since the LTCI implementation and remained stable over time. The impact was more pronounced among those with longer coverage. The overall reduction was stronger in those who were not married, lived alone, and resided in institutions. CONCLUSIONS: LTCI may reduce the occurrence of all-cause, PI-, and UTI-related hospitalizations in OPWD, with stronger influences observed over an extended period of implementation. The implementation of LTCI can play a role in reducing the burden of infectious diseases in OPWD and the care burden of families and society.

Association between perceived noise at work and mental health among employed adults in Southwest China.

BACKGROUND: Perceived noise at work may contribute more to worsening mental health than objectively measured noise. However, evidence regarding this association is scarce. We investigated the associations of perceived noise at work with anxiety and depression and identified vulnerable subpopulations. METHODS: Data from 28,661 participants of the Chinese Cohort of Working Adults (CCWA) were analyzed. Logistic or multinomial logistic regression models were used to determine associations between perceived noise at work and the severity of probable anxiety, depression, and their comorbidity. The generalized additive model with restricted cubic splines was applied to estimate the non-linear trend of associations. RESULTS: The mean age of participants was 36.55 ± 10.42 years. We observed that a higher level of perceived noise at work was associated with a higher risk of severe anxiety (OR = 1.55. 95%CI: 1.51-1.59) and severe depression (OR = 1.77. 95%CI: 1.72-1.84). More perceived noise at work was further associated with increased odds of comorbid anxiety and depression (OR = 1.28, 95%CI: 1.26-1.30). We observed an approximately J-shaped curve for the association between perceived noise at work with anxiety, depression, and their comorbidity. Participants, who were male, aged <45 years, had high education levels, and worked on trains were characterized by a greater impact of perceived noise at work on mental health problems. CONCLUSION: Increased perceived noise at work was associated with an elevated risk of anxiety, depression, and their comorbidity. These associations were moderated by sex, age, education level and occupation. Interventions targeting perceived noise at work may promote employed adults' mental health.

Occupational burnout, flourishing and job satisfaction among HIV/AIDS healthcare workers in Western China: a network analysis.

BACKGROUND: Healthcare workers suffered with high prevalence of occupational burnout, which might be related with their job satisfaction and well-being. This study aimed to provide evidence of complex interrelations among occupational burnout, flourishing, and job satisfaction, and identify key variables from the perspective of network structure among healthcare workers. METHODS: A cross-sectional study was conducted between July and October 2021, and 907 (the response rate was 98.4%) HIV/AIDS healthcare workers completed their sociodemographic characteristics, occupational burnout, flourishing and job satisfaction. Network analysis was conducted to investigate the interrelations of occupational burnout, flourishing, and job satisfaction communities, and identify central variables and bridges connecting different communities with different bridge strength thresholds in the network structure. The Network Comparison Test (NCT) was conducted to examine the gender differences in networks. RESULTS: In the network, feeling exhausted at work (strength: 1.42) and feeling frustrated at work (1.27) in occupational burnout community, and interested in daily activities (1.32) in flourishing community were central variables. Bridges in the network were job reward satisfaction (bridge strength: 0.31), satisfaction with job itself (0.25), and job environment satisfaction (0.19) in job satisfaction community, as well as interested in daily activities (0.29) and feeling respectable (0.18) in flourishing community, with bridges selected with top 20% bridge strengths. Feeling frustrated at work (0.14) in occupational burnout community and leading a purposeful and meaningful life (0.11) in flourishing community became bridges when using thresholds of top 25% and 30% bridge strengths, respectively. We also observed higher network densities in females (network density: 0.37) than that in males (0.34), and gender differences in the distribution of partial correlation coefficients (M = 0.27, P = 0.017). CONCLUSIONS: In the network structure of occupational burnout-flourishing-job satisfaction, feeling frustrated at work in occupational burnout community and interested in daily activities in flourishing community were both central variables and bridges, which may be targeted variables to intervene to alleviate the overall level of symptoms in the network and therefore prevent poor health outcomes in healthcare workers.

Roles of Social Capital in the Association Between Internalized Homophobia and Condomless Sex Among Men Who Have Sex With Men in Southwest China: A Four-Way Decomposition.

Objectives: This study examined whether social capital (SC) mediated the association between internalized homophobia (IH) and condomless sex among men who have sex with men (MSM), with the interaction of SC and IH considered. Methods: A cross-sectional study was conducted between November 2018 and April 2019 in Sichuan Province, China. A total of 540 participants were recruited to investigate their IH, SC, and condomless sex. A four-way decomposition of causal mediation analysis was used to test SC's roles in the association between IH and condomless sex. Results: Condomless sex was prevalent (46.7%) among the participants, which was significantly associated with IH [odds ratio (OR) = 1.70] and SC (OR = 0.55). A direct effect [excess risk ratio (RR = 0.32)] and an indirect effect (excess RR = 0.16) of SC were found to be significant in the association between IH and condomless sex. Heterogeneities in effects were observed when taking the SC's domains (e.g., individual and family-based SC) as mediators. SC's effects were significant only in the homosexual subgroup. Conclusion: IH-based intervention with consideration of SC can be tailored to MSM to decrease condomless sex and curb the spread of HIV, especially for the homosexual subgroup.

Associations between residential greenness and the predicted 10-year risk for atherosclerosis cardiovascular disease among Chinese adults.

BACKGROUND: Exposure to build environments, especially residential greenness, offers benefits to reduce the development of atherosclerotic cardiovascular diseases (ASCVD). The 10-year ASCVD risk is a useful indicator for long-term ASCVD risk, but the evidence on the association and potential pathway of residential greenness in mitigating its development remains unclear. OBJECTIVES: This study aimed to investigate the associations between residential greenness and the 10-year predicted ASCVD risks, and potentially mediation effect on this association by air pollution, body mass index (BMI) and physical activity (PA). METHODS: The baseline of the China Multi-Ethnic Cohort (CMEC) study, enrolling 99,556 adults during 2018-2019, was used in this cross-sectional study. The participants' 10-year ASCVD risks were predicted as low-, moderate-, and high-risk groups, based on the six risk factors: age, smoking, hypertension, low-density lipoprotein cholesterol (LDL-C), high high-density lipoprotein cholesterol (HDL-C), and high total cholesterol (TC). The 3-year mean value within the circular buffer of 500 m and 1000 m of Enhanced Vegetation Index (EVI500m and EVI1000m) were used to assess greenness exposure. Multiple logistic regression was used to evaluate the association between residential greenness and the 10-year ASCVD risks. Stratified analyses by sex, age and smoking status were performed to identify susceptible populations. Causal mediation analysis was used to explore the mediation effects of air pollution, BMI and PA. RESULTS: A total of 75,975 participants were included, of which 17.9 % (n = 13,614) and 5.6 % (n = 4253) had the moderate and high 10-year ASCVD risks, respectively. Compared to the low-risk group, each interquartile increase in EVI500m and EVI1000m reduced the ASCVD risk of the moderate-risk group by 4 % (OR = 0.96 [0.94, 0.98]) and 4 % (OR = 0.96 [0.94, 0.98]), respectively; and reduced the risk of the high-risk group by 8 % (OR = 0.92 [0.90, 0.96]) and 7 % (OR = 0.93 [0.90, 0.97]), respectively. However, the increased greenness did not affect the ASCVD risk of the high-risk group when compared to the moderate-risk group. Effects of residential greenness on the ASCVD risk were stronger in women than in men (p < 0.05), and were not observed in those aged ≥55. PA and BMI partially mediated the association between greenness and the 10-year ASCVD risk. CONCLUSIONS: ASCVD prevention strategies should be tailored to maximize the effectiveness within the groups with different ASCVD risks, better at early stages when the ASCVD risk is low.

Rural-urban disparities in the associations of residential greenness with diabetes and prediabetes among adults in southeastern China.

AIMS: Greenness offers health benefits to prevent diabetes in urban areas. However, urban-rural disparities in this association have not been explored, with the underlying pathways understudied as well. We aimed to investigate and compare the associations and potential pathways between residential greenness and the risks for diabetes and prediabetes in urban and rural areas. METHODS: Diabetes and prediabetes were diagnosed by fasting blood glucose (FBG). The participants' residential greenness exposure was estimated by the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). The association of residential greenness with the risks for diabetes and prediabetes was estimated by logistic regression and the generalized additive model. The potential mediation effects of air pollution, body mass index (BMI), and physical activity (PA) were examined by causal mediation analysis. RESULTS: Of the 50,593 included participants, and the prevalence of prediabetes and diabetes were 21.22 % and 5.63 %, respectively. Each 0.1-unit increase in EVI500m and NDVI500m for healthy people reduced the risk for prediabetes by 12 % and 8 %, respectively, and substantially reduced the risk for diabetes by 23 % and 19 %, respectively. For those with prediabetes, each 0.1-unit increase in EVI500m and NDVI500m reduced the diabetes risk by 14 % and 12 %, respectively. Compared to the risks for diabetes at the 25th percentile of EVI500m/NDVI500m, such risks significantly reduced when EVI500m (NDVI500m) increased over 0.43 (0.48) and 0.28 (0.39) in urban and rural areas, respectively. The residential greenness-prediabetes/diabetes associations were mediated by air pollution and PA in urban areas and by air pollution and BMI in rural areas. CONCLUSIONS: Exposure to residential greenness was associated with a lower risk for prediabetes and diabetes in urban areas and, more strongly, in rural areas, which were partly mediated by air pollution, PA, and BMI.

Residential greenness and dyslipidemia risk: Dose-response relations and mediation through BMI and air pollution.

BACKGROUND: Evidence on associations of residential greenness with dyslipidemia is limited, particularly regarding dose-response relations and mediation. OBJECTIVES: To investigate associations between greenness and dyslipidemia, non-linear dose-response relationships and mediators. METHODS: This cross-sectional study draws on the 2018 Fujian Behavior and Disease Surveillance (FBDS) cohort that used multi-stage stratified random sampling from the general population of Fujian Province, China. Participants with one or more abnormities in total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), or low-density lipoprotein cholesterol (LDL-C) were classified as having dyslipidemia. Residential greenness was operationalized as 3-year average of the normalized difference vegetation index (NDVI500m) and enhanced vegetation index (EVI500m). A doubly robust approach was used for effect quantification. Dose-response relations were studied with natural cubic splines. Mediation via physical activity (PA), body mass index (BMI), PM2.5, PM10, SO2, and NO2 was also examined. RESULTS: Data from 43,183 participants were analyzed. Increases in NDVI500m and EVI500m residential greenness were associated with decreased dyslipidemia risk and improved blood lipids. Non-linear dose response relationships were discovered. Significant reduction of dyslipidemia risk was observed at levels of EVI500m > 0.48 and NDVI500m > 0.65. Joint mediation effects of PA, BMI, PM2.5, PM10, NO2, and SO2 on the associations of NDVI500m and EVI500m with dyslipidemia risk were 49.74% and 44.64%, respectively. CONCLUSIONS: Increased residential exposure to greenness was associated with decreased risk of dyslipidemia. A non-linear dose-response relationship between greenness and dyslipidemia suggests that specific thresholds of greenness need to be reached in order to achieve effects. BMI, PM2.5, and PM10 partially mediated the association.

Association between residential greenness and all-cause mortality and the joint mediation effect of air pollutants among old people with disability: A prospective cohort study.

BACKGROUND: Residential greenness offers health benefits to old people, but evidence of its association with the health of old people with disability is scarce. Moreover, due to the limited mobility of this vulnerable population, air pollutants may play an indispensable mediating role in that association, which however remains understudied. OBJECTIVES: This study aimed to investigate the association between residential greenness and all-cause mortality risk and the joint mediation effect of air pollutants among old people with disability. METHODS: A total of 34,075 old people with disability were included in the Chengdu Long-term Care Insurance cohort. Participants' residential greenness exposure was measured by an enhanced vegetation index within the 500 m buffer zone (EVI500m). Causal mediation analysis was conducted to assess the total effect (TE) of residential greenness and the natural indirect effect (NIE) through PM2.5, CO, NO2, SO2, and O3 on all-cause mortality. RESULTS: The TE of EVI500m on the all-cause mortality risk in overall participants showed negative, which, decreased from the 2nd quartile (HR = 0.93, 95 % CI: 0. 91, 0.95) to the 4th quartile (HR = 0.81, 95 % CI: 0.76, 0.85); the NIE through the five air pollutants also decreased from the 2nd quartile (HR = 0.96, 95 % CI: 0.95, 0.98) to the 4th quartile (HR = 0.90, 95 % CI: 0.88, 0.93), with the proportion mediated decreased from 48 % to 44 %. The stronger TE or NIE were observed in participants aged <80 years old, men, with mild-moderate disability, and having outdoor experience every week. CONCLUSION: Exposure to residential greenness was associated with a decreased risk of mortality, partially through the pathways of air pollutants, which varied by age, sex, degree of disability, and frequency of weekly outdoors. Our findings would provide evidence to develop aging-friendly cities.