[Exploring implementation strategies for healthy longevity among the elderly population in China based on the delphi method].

Objective: To explore the implementation strategies for promoting healthy longevity among the elderly population in China based on the Delphi method. Methods: Through literature review and expert discussion, a framework for implementation strategies to achieve healthy longevity among the elderly was determined, and a preliminary checklist of implementation strategies was developed. The Delphi method was employed from August to December 2022, inviting 25 experts from various disciplines such as clinical medicine, public health, basic research, and the elderly care services industry. Experts were sent consultation questionnaires via email to assess the importance, feasibility, judgment basis and familiarity of each implementation strategy. Active coefficient, authority coefficient, and harmony coefficient were analyzed to ultimately determine the important and feasible implementation strategies for healthy longevity that were suitable for the Chinese elderly population. Results: The expert active coefficients of the two rounds were 96.00% (24/25) and 79.17% (19/24). The authority coefficients were (0.76±0.19) and (0.77±0.17). The average scores of importance were (4.32±0.84) and (4.36±0.82), and the corresponding scores of feasibility were (3.72±1.04) and (3.80±0.92). The harmony coefficients for the importance score were 0.269 (χ2=594.084, P<0.001) and 0.159 (χ2=193.624, P<0.001). The harmony coefficients for feasibility scores were 0.205 (χ2=452.008, P<0.001) and 0.167 (χ2=202.878, P<0.001). The final eight implementation strategies were identified after two rounds of consultation. Conclusion: Through two rounds of Delphi consultations, eight important and feasible implementation strategies for promoting healthy longevity that are suitable for the Chinese context have been proposed.

[Exploring a definition of healthy longevity in Chinese population based on Delphi method].

Objective: To explore a definition of healthy longevity in the Chinese population based on the Delphi method. Methods: Through a comprehensive literature review and expert consultation, the dimensions in the definition of healthy longevity were identified, and a preliminary list of questions was created. Experts in clinical medicine, public health, basic research, and the elderly care service industry, who had been working in the field of geriatric health for at least 5 years, were invited to participate in the Delphi survey from August to December 2022. The survey questionnaires were administered via email in two rounds, and experts were asked to select the optimal options from the provided questions. The active coefficients were expressed by the response rate, and a consensus was reached when the largest number of experts agreed for single-choice questions and more than 70% agreed for multiple-choice questions. Results: In the two rounds, the active coefficients were 96.00% (24/25) and 79.17% (19/24), respectively, and a consensus was finally reached on nine items, including age, physical health, common metabolic indicators, mental health, cognitive function, functional ability, social activity, self-rated health, and subjective well-being. Following discussions among the research team and experts, a final definition of healthy longevity was determined. Healthy longevity could refer to a state of good physical, psychological, cognitive function and social adaptation, as well as subjective well-being, in individuals aged 90 and above. Specifically, individuals with healthy longevity should be free from diseases associated with high disability rates and mortality, such as stroke, cancer, and Parkinson's disease. They should also maintain reasonable levels of common non-communicable disease indicators, such as blood pressure and blood glucose, and exhibit favorable mental health and cognitive function using validated measurement tools. In addition, individuals with healthy longevity should engage in social interactions with friends and relatives, care for family members, and go out to do things. Meanwhile, with the ability to complete the visual and hearing functions of daily life and communication, and the ability to complete basic activities such as walking, eating, bathing, toileting, dressing, continence of urination, and bowel movement independently, they could rate themselves to be in good health and experience a relatively high level of life satisfaction. Conclusion: A definition of healthy longevity in the Chinese population is established through the two-round Delphi consultation.

[A panel study on the association of organophosphate ester flame retardant exposure with thyroid function related hormones in healthy older adults].

Objective: To explore the impact of whole blood organophosphate esters (OPEs) flame retardant exposure on thyroid function-related hormones in healthy older adults. Methods: In this panel study, five repeated population-based epidemiological surveys and biological sample collection were conducted from September 2018 to January 2019, with 76 healthy older adults aged 60-69 years in the Dianliu Community of Jinan, Shandong Province. Information on the sociodemographic characteristics, diet, and health status of the respondents was systematically gathered through questionnaires and physical examinations. Fasting venous blood was collected to determine the levels of OPEs, thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4). A linear mixed-effects model was used to analyze the impact of OPEs exposure on thyroid function-related hormones in healthy older adults. Results: Each of the 76 subjects participated in at least two follow-up visits, resulting in a total of 350 person visits. The age of the study participants was (65.07±2.76) years, with 38 participants of both sexes. A total of eight OPEs were included with a detection rate exceeding 50%, and the M (Q1, Q3) for ∑OPEs was 3.85 (2.33, 5.74) ng/ml, with alkyl-OPEs being the major type of OPEs with an M (Q1, Q3) of 1.27 (0.64, 2.50) ng/ml. The M (Q1, Q3) for TSH, T3, and T4 was 3.74 (2.55, 5.69) µIU/ml, 1.32 (1.10, 1.60) ng/ml, and 45.04 (36.96, 53.27) ng/ml, respectively. Linear mixed-effects model showed that TSH was significantly decreased by 9.93% (95%CI:-15.17%, -4.36%) and 11.14% (95%CI:-15.94%, -6.06%) in older adults for each quartile level increase in TnBP and TEHP exposures, respectively. Gender-stratified analysis indicated that TEHP exposure was negatively associated with TSH levels in male older adults, whereas a decrease in TSH levels among female older adults was associated with TnBP exposure. Conclusion: Exposure to whole blood OPEs is associated with decreased TSH levels among healthy older adults, with notable gender differences.

[Association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40-89 in selected areas of China].

Objective: To investigate the association of urinary cadmium levels with peripheral leukocyte classification counts among middle-aged and older adults aged 40 to 89 years in selected areas of China. Methods: The research was based on the survey of the impact of soil quality of agricultural land on human health in typical areas conducted in 2019-2020. A total of 5 600 middle-aged and older adults aged 40 to 89 years were included by using a multi-stage stratified random sampling method. Baseline characteristics of the subjects were collected and physical examinations were performed. Random midstream urine was collected to measure urinary cadmium and urinary creatinine and fasting venous blood was collected to measure the leukocyte count, neutrophil count, lymphocyte count, monocyte count and eosinophil count. The linear mixed effect model was used to analyse the association of urinary cadmium levels with leukocyte classification counts, and the dose-response relationship between them was analyzed by using the restricted cubic spline (RCS) function. Results: The age of the subjects was (63.17±12.02) years; 2 851 (50.91%) were males; and the M (Q1, Q3) of urinary creatinine-corrected urinary cadmium levels was 2.69 (1.52, 4.69) µg/g·creatinine. After adjusting for confounding factors, the results of linear mixed effects model analysis showed that for each 1-unit increase in urinary creatinine-corrected urinary cadmium level, the percentage change [% (95%CI)] of leukocyte count and lymphocyte count was -1.70% (-2.61%, -0.79%) and -1.57% (-2.86%, -0.26%), respectively. RCS function showed a negative linear relationship between urinary creatinine-corrected urinary cadmium levels and leukocyte counts and lymphocyte counts, respectively (all Pnon-linear>0.05). Conclusion: Urinary cadmium levels are negatively associated with leukocyte count and lymphocyte count among middle-aged and older adults aged 40 to 89 years in selected areas of China.

[Association of urinary cadmium level with body mass index and body circumferences among older adults over 65 years old in 9 longevity areas of China].

Objective: To investigate the association of urinary cadmium level with body mass index (BMI) and body circumferences among the older adults over 65 years old in 9 longevity areas of China. Methods: Subjects were older adults over 65 years old from the Healthy Aging and Biomarkers Cohort Study (HABCS) between 2017 and 2018 conducted in 9 longevity areas in China. A total of 1 968 older adults were included in this study. Information including socio-demographic characteristics, lifestyles, diet intake, and health status was collected by using questionnaires and physical examinations. Urine samples were collected to detect urinary cadmium and creatinine levels. Body circumferences included waist circumference, hip circumference and calf circumference. Subjects were divided into three groups (low:<0.77 µg/g·creatinine, middle:0.77-1.69 µg/g·creatinine, high:≥1.69 µg/g·creatinine) by tertiles of creatinine-adjusted urinary cadmium concentration. Multiple linear regression models were used to analyze the association of creatinine-adjusted urinary cadmium level with BMI and body circumferences. The dose-response relationship of creatinine-adjusted urinary cadmium concentration with BMI and body circumferences was analyzed by using restrictive cubic splines fitting multiple linear regression model. Results: The mean age of subjects was (83.34±11.14) years old. The median (Q1, Q3) concentration of creatinine-adjusted urinary cadmium was 1.13 (0.63, 2.09) µg/g·creatinine, and the BMI was (22.70±3.82) kg/m2. The mean values of waist circumference, hip circumference, and calf circumference were (85.42±10.68) cm, (92.67±8.90) cm, and (31.08±4.76) cm, respectively. After controlling confounding factors, the results of the multiple linear regression model showed that for each increment of 1 µg/g·creatinine in creatinine-adjusted urinary cadmium, the change of BMI, waist circumference, hip circumference, and calf circumference in the high-level group was -0.28 (-0.37, -0.19) kg/m2, -0.74 (-0.96, -0.52) cm, -0.78 (-0.96, -0.61) cm, and -0.20 (-0.30, -0.11) cm, respectively. The restrictive cubic splines curve showed a negative nonlinear association of creatinine-adjusted urinary cadmium with BMI (Pnonlinear<0.001) and negative linear associations of creatinine-adjusted urinary cadmium with waist circumference (Plinear<0.001), hip circumference (Plinear<0.001), and calf circumference (Plinear<0.001). Conclusion: Urinary cadmium level is significantly associated with decreased BMI, waist circumference, hip circumference and calf circumference among older adults over 65 years old in 9 longevity areas of China.

[Revision and prospect of the "Standards for Drinking Water Quality (GB5749-2022)" in China].

The revision of the national standards for drinking water quality is an important, rigorous and delicate endeavor. The paper introduced the revision of this standard, emphasizing the revision principle, overall technical considerations, and revision contents. Recommendations were also proposed for the implementation of this standard.

[Revision and prospect of "Standards for indoor air quality（GB/T 18883-2022）" in China].

The formulation and revision of the detection methods of indoor air quality standards is an important, rigorous and delicate endeavor. The standards for indoor air quality (GB/T 18883-2022) were issued by the State Administration of Market Regulation and the Standardization Administration on July 11, 2022, and implemented on February 1, 2023 by replacing indoor air quality standards (GB/T 18883-2002). The revised standard specifies hygienic requirements for physical, chemical, biological and radioactive indicators in indoor air and the corresponding test methods. This article interpreted the revision background, drafting principles, main indicators and methods, as well as the revision basis of the standards. Recommendations for the implementation of the standards are also proposed.

[Research on the formulation and revision of standard limits for antimony,boron and vanadium in the "Standards for Drinking Water Quality (GB5749-2022)" in China].

China is rich in antimony, boron, and vanadium mineral resources, which have been detected in environmental water bodies and drinking water. During the revision process of the "Standards for Drinking Water Quality (GB5749-2006)", research and evaluation are focused on three indicators: antimony, boron and vanadium. Vanadium is added and the limit value of boron is adjusted. This study reviews and discusses the technical contents related to the revision of the antimony, boron and vanadium, including the environmental presence levels, exposure status, health effects, and the revision of the standard limits of these three indicators. Suggestions are also made for the implementation of this standard.

[Study on formulation and revision of standard limits for inhalable particulate matter (PM10) and fine particulate matter (PM2.5) in "Standards for indoor air quality（GB/T 18883-2022）" in China].

The pollution and health effects of indoor inhalable particulate matter (PM10) and fine particulate matter (PM2.5) are increasingly receiving public attention. The"Standards for indoor air quality (GB/T 18883-2022)"has revised the standard limit for PM10 and added the standard limit for PM2.5. This study analyzed and interpreted the relevant technical contents of the revision of the standard limits for two indicators, including the exposure status, health effects, and the basis for the determination of the limit value. It also proposed prospects for the future development and revision of standard limits for indoor particulate matters.

[A panel study on the effect of atmospheric PM2.5 exposure on the gut microbiome in healthy elderly people aged 60-69 years old].

Objective: To analyze the short-term effect of individual atmospheric PM2.5 exposure on the diversity, enterotype, and community structure of gut microbiome in healthy elderly people in Jinan, Shandong province. Methods: The present panel study recruited 76 healthy elderly people aged 60-69 years old in Dianliu Street, Lixia District, Jinan, Shandong Province, and followed them up five times from September 2018 to January 2019. The relevant information was collected by questionnaire, physical examination, precise monitoring of individual PM2.5 exposure, fecal sample collection and gut microbiome 16S rDNA sequencing. The Dirichlet multinomial mixtures (DMM) model was used to analyze the enterotype. Linear mixed effect model and generalized linear mixed effect model were used to analyze the effect of PM2.5 exposure on gut microbiome α diversity indices (Shannon, Simpson, Chao1, and ACE indices), enterotype and abundance of core species. Results: Each of the 76 subjects participated in at least two follow-up visits, resulting in a total of 352 person-visits. The age of 76 subjects was (65.0±2.8) years old with BMI (25.0±2.4) kg/m2. There were 38 males accounting for 50% of the subjects. People with an educational level of primary school or below accounted for 10.5% of the 76 subjects, and those with secondary school and junior college or above accounting for 71.1% and 18.4%. The individual PM2.5 exposure concentration of 76 subjects during the study period was (58.7±53.7) µg/m3. DMM model showed that the subjects could be divided into four enterotypes, which were mainly driven by Bacteroides, Faecalibacterium, Lachnospiraceae, Prevotellaceae, and Ruminococcaceae. Linear mixed effects model showed that different lag periods of PM2.5 exposure were significantly associated with a lower gut α diversity index (FDR<0.05 after correction). Further analysis showed that PM2.5 exposure was significantly associated with changes in the abundances of Firmicutes (Megamonas, Blautia, Streptococcus, etc.) and Bacteroidetes (Alistipes) (FDR<0.05 after correction). Conclusion: Short-term PM2.5 exposure is significantly associated with a decrease in gut microbiome diversity and changes in the abundance of several species of Firmicutes and Bacteroidetes in the elderly. It is necessary to further explore the underlying mechanisms between PM2.5 exposure and the gut microbiome, so as to provide a scientific basis for promoting the intestinal health of the elderly.

[Association of sleep duration and risk of frailty among the elderly over 80 years old in China: a prospective cohort study].

Objective: To explore the association between sleep duration and the risk of frailty among the elderly over 80 years old in China. Methods: Using the data from five surveys of the China Elderly Health Influencing Factors Follow-up Survey (CLHLS) (2005, 2008-2009, 2011-2012, 2014, and 2017-2018), 7 024 elderly people aged 80 years and above were selected as the study subjects. Questionnaires and physical examinations were used to collect information on sleep time, general demographic characteristics, functional status, physical signs, and illness. The frailty state was evaluated based on a frailty index that included 39 variables. The Cox proportional risk regression model was used to analyze the correlation between sleep time and the risk of frailty occurrence. A restricted cubic spline function was used to analyze the dose-response relationship between sleep time and the risk of frailty occurrence. The likelihood ratio test was used to analyze the interaction between age, gender, sleep quality, cognitive impairment, and sleep duration. Results: The age M (Q1, Q3) of 7 024 subjects was 87 (82, 92) years old, with a total of 3 435 (48.9%) patients experiencing frailty. The results of restricted cubic spline function analysis showed that there was an approximate U-shaped relationship between sleep time and the risk of frailty. When sleep time was 6.5-8.5 hours, the elderly had the lowest risk of frailty; Multivariate Cox proportional risk regression model analysis showed that compared to 6.5-8.5 hours of sleep, long sleep duration (>8.5 hours) increased the risk of frailty by 13% (HR: 1.13; 95%CI: 1.04-1.22). Conclusion: There is a nonlinear association between sleep time and the risk of frailty in the elderly.

[Association of plasma vitamin B12 level with plasma uric acid level among the elderly over 65 years old in 9 longevity areas of China].

Objective: To investigate the association of plasma vitamin B12 level with plasma uric acid level among the elderly over 65 in 9 longevity areas of China. Methods: The elderly over 65 years old with complete information on plasma vitamin B12 and plasma uric acid from Healthy Aging and Biomarkers Cohort Study (2017 to 2018) were recruited in this study. Information on socio-demographic characteristics, life styles, diet intake, and health status were collected by questionnaire and physical examination; and fasting venous blood was collected to detect the levels of plasma vitamin B12, uric acid and other indicators. Multiple linear regression models were used to analyze the association of plasma vitamin B12 level per interquartile range increase with plasma uric acid level. The association trend of plasma vitamin B12 level with plasma uric acid level was described by restrictive cubic splines fitting multiple linear regression model. Multiple logistic regression models were used to analyze the association of plasma vitamin B12 level stratified by quartiles with hyperuricemia. Results: A total of 2 471 participants were finally included in the study, the age was (84.88±19.76) years old, of which 1 291 (52.25%) were female. The M (Q1, Q3) level of plasma vitamin B12 was 294 (203, 440) pg/ml and the plasma uric acid level was (341.01±90.46) µmol/L. A total of 422 participants (17.08%) were defined with hyperuricemia. The results of multiple linear regression model showed that there was a positive association of plasma vitamin B12 level with plasma uric acid level after adjustment for covariates (P<0.05). An IQR increase in plasma vitamin B12 (237 pg/ml) was associated with a 6.36 (95%CI: 2.00-10.72) µmol/L increase in the plasma uric acid level. The restrictive cubic splines curve showed a positive linear association of log-transformed plasma vitamin B12 with uric acid level (P<0.001). Conclusion: There is a positive association of plasma vitamin B12 level with plasma uric acid level among the elderly over 65 years old in 9 longevity areas of China.

[Association of greenness, nitrogen dioxide with the prevalence of hypertension among the elderly over 65 years old in China].

Objective: To investigate the association of mixed exposure to greenness and nitrogen dioxide(NO2) and hypertension among the older adults aged 65 years and over in China. Methods: The study subjects were from the Chinese Longitudinal Healthy Longevity Survey from 2017 to 2018. A total of 15 423 older adults aged 65 years and over meeting the criteria were finally included in the study. A questionnaire survey was used to collect information on demographic characteristics, lifestyle habits and self-reported prevalence of hypertension. Blood pressure values were obtained through physical examination. The level of normalized difference vegetation index(NDVI) was measured by the Medium-resolution Imaging Spectral Radiator(MODIS) of the National Aeronautics and Space Administration(NASA). The concentration of NO2 was from China's surface air pollutant data set. Meteorological data was from NASA MERRA-2. The exposure to NDVI and NO2 for each study subject was calculated based on the area within a 1 km radius around their residence. The association between mixed exposure of NDVI and NO2 as well as their interaction and hypertension in older adults was analyzed by using the multivariate logistic regression model. The restrictive cubic spline(RCS) function was used to explore the exposure-response relationship between greenness and NO2 and the risk of hypertension in study subjects. Results: The mean age of 15 423 older adults were (85.6±11.6). Women accounted for 56.3%(8 685/15 423) and 55.6%(8 578/15 423) lived in urban areas. The mean time of residence was (60.9±28.5) years. 59.8% of participants were with hypertension. The mean NDVI level was 0.41±0.13, and the mean NO2 concentration was (32.18±10.36) µg/cm3. The results of multivariate logistic regression analysis showed that NDVI was inversely and linearly associated with the hypertension in older adults, with the OR(95%CI) value of 0.959(0.928-0.992). Compared with the T1 group of NDVI, the risk of hypertension was lower in the T3 group, with the OR(95%CI) value of 0.852(0.769-0.944), and the trend test was statistically significant(P<0.05). Compared with the T1 group of NO2, the risk of hypertension was higher in the T2 and T3 groups, with OR(95%CI) values of 1.160(1.055-1.275) and 1.244(1.111-1.393), and the trend test was statistically significant (P<0.05). The result of the RCS showed that NDVI was inversely and linearly associated with hypertension in older adults. NO2 was nonlinearly associated with hypertension in older adults. The interaction analysis showed that NDVI and NO2 had a negative multiplicative interaction on the risk of hypertension, with OR(95%CI) value of 0.995(0.992-0.997). Conclusion: Exposure to greenness and NO2 are associated with hypertension in older adults.

[Association between cognitive impairment and main metals among oldest old aged 80 years and over in China].

Objective: To identify the main metals involved in cognitive impairment in the Chinese oldest old, and explore the association between these metal exposures and cognitive impairment. Methods: A cross-sectional study was conducted on 1 568 participants aged 80 years and older from Healthy Aging and Biomarkers Cohort Study (2017 to 2018). Fasting venous blood was collected to measure the levels of nine metals (selenium, lead, cadmium, arsenic, antimony, chromium, manganese, mercury, and nickel). The cognitive function of these participants was evaluated by using the Chinese version of the Mini-Mental State Examination (CMMSE). The random forest (RF) was applied to independently identify the main metals that affected cognitive impairment. The multivariate logistic regression model and restricted cubic splines (RCS) model were used to further verify the association of the main metals with cognitive impairment. Results: The age of 1 568 study subjects was (91.8±7.6) years old, including 912 females (58.2%) and 465 individuals (29.7%) with cognitive function impairment. Based on the RF model (the out-of-bag error rate was 22.9%), the importance ranking of variables was conducted and the feature screening of five times ten-fold cross-validation was carried out. It was found that selenium was the metal that affected cognitive function impairment, and the other eight metals were not included in the model. After adjusting for covariates, the multivariate logistic regression model showed that with every increase of 10 µg/L of blood selenium levels, the risk of cognitive impairment decreased (OR=0.921, 95%CI: 0.889-0.954). Compared with the lowest quartile(Q1) of blood selenium, the ORs (95%CI) of Q3 and Q4 blood selenium were 0.452 (0.304-0.669) and 0.419 (0.281-0.622) respectively. The RCS showed a linear dose-response relationship between blood selenium and cognitive impairment (Pnonlinear>0.05). Conclusion: Blood selenium is negatively associated with cognitive impairment in the Chinese oldest old.

[Association between urinary arsenic level and serum testosterone in Chinese men aged 18 to 79 years].

Objective: To investigate the association between the urinary arsenic level and serum total testosterone in Chinese men aged 18 to 79 years. Methods: A total of 5 048 male participants aged 18 to 79 years were recruited from the China National Human Biomonitoring (CNHBM) from 2017 to 2018. Questionnaires and physical examinations were used to collect information on demographic characteristics, lifestyle, food intake frequency and health status. Venous blood and urine samples were collected to detect the level of serum total testosterone, urinary arsenic and urinary creatinine. Participants were divided into three groups (low, middle, and high) based on the tertiles of creatinine-adjusted urinary arsenic concentration. Weighted multiple linear regression was fitted to analyze the association of urinary arsenic with serum total testosterone. Results: The weighted average age of 5 048 Chinese men was (46.72±0.40) years. Geometric mean concentration (95%CI) of urinary arsenic, creatinine-adjusted urinary arsenic and serum testosterone was 22.46 (20.08, 25.12) µg/L, 19.36 (16.92, 22.15) µg/g·Cr and 18.13 (17.42, 18.85) nmol/L, respectively. After controlling for covariates, compared with the low-level urinary arsenic group, the testosterone level of the participants in the middle-level group and the high-level group decreased gradually. The percentile ratio (95%CI) was -5.17% (-13.14%, 3.54%) and -10.33% (-15.68%, -4.63). The subgroup analysis showed that the association between the urinary arsenic level and testosterone level was more obvious in the group with BMI<24 kg/m2 group (Pinteraction=0.023). Conclusion: There is a negative association between the urinary arsenic level and serum total testosterone in Chinese men aged 18 to 79 years.

[The role of Keap1/Nrf2/HO-1 signal pathway in liver injury induced by rare earth neodymium oxide in mice].

Objective: To investigate the role of Keap1/Nrf2/HO-1 signaling pathway in liver injury induced by neodymium oxide (Nd(2)O(3)) in mice. Methods: In March 2021, forty-eight SPF grade healthy male C57BL/6J mice were randomly divided into control group (0.9% NaCl), low dose group (62.5 mg/ml Nd(2)O(3)), medium dose group (125.0 mg/ml Nd(2)O(3)), and high dose group (250.0 mg/ml Nd(2)O(3)), each group consisted of 12 animals. The infected groups were treated with Nd(2)O(3) suspension by non-exposed tracheal drip and were killed 35 days after dust exposure. The liver weight of each group was weighed and the organ coefficient was calculated. The content of Nd(3+) in liver tissue was detected by inductively coupled plasma mass spectrometry (ICP-MS). HE staining and immunofluorescence was used to observe the changes of inflammation and nuclear entry. The mRNA expression levels of Keap1, Nrf2 and HO-1 in mice liver tissue were detected by qRT-PCR. Western blotting was used to detect the protein expression levels of Keap1 and HO-1. The contents of catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) were detected by colorimetric method. The contents of interleukin 1ß (IL-1ß), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by ELISA. The data was expressed in Mean±SD. Two-independent sample t-test was used for inter-group comparison, and one-way analysis of variance was used for multi-group comparison. Results: Compared with the control group, the liver organ coefficient of mice in medium and high dose groups were increased, and the Nd(3+) accumulation in liver of mice in all dose groups were significantly increased (P<0.05). Pathology showed that the structure of liver lobules in the high dose group was slightly disordered, the liver cells showed balloon-like lesions, the arrangement of liver cell cords was disordered, and the inflammatory exudation was obvious. Compared with the control group, the levels of IL-1ß and IL-6 in liver tissue of mice in all dose groups were increased, and the levels of TNF-α in liver tissue of mice in high dose group were increased (P<0.05). Compared with the control group, the mRNA and protein expression levels of Keap1 in high dose group were significantly decreased, while the mRNA expression level of Nrf2, the mRNA and protein expression levels of HO-1 were significantly increased (P<0.05), and Nrf2 was successfully activated into the nucleus. Compared with the control group, the activities of CAT, GSH-Px and T-SOD in high dose group were significantly decreased (P<0.05) . Conclusion: A large amount of Nd(2)O(3) accumulates in the liver of male mice, which may lead to oxidative stress and inflammatory response through activation of Keap1/Nrf2/HO-1 signal pathway. It is suggested that Keap1/Nrf2/HO-1 signal pathway may be one of the mechanisms of Nd(2)O(3) expose-induced liver injury in mice.

[Strengthening the research on the key factors and related mechanisms of elderly health].

The process of population aging is gradually deepening, and the problems of disability, cognitive impairment and frailty are widely prevalent among the elderly in China. The key to healthy aging is to optimize functional ability, which is not only related to healthy people; many older adults suffer from one or more diseases, which do not affect their functional ability. The health of the elderly is affected by multi-dimensional factors such as heredity, environment, lifestyle, social behavior and mental psychology. Previous studies, focusing on the outcomes of death, diseases, functional ability and intrinsic capacity decline, have revealed a series of distribution characteristics and influencing factors, and found that there are special epidemiological characteristics on health among the oldest-old and are different from that in the general elderly. Nevertheless, there are still insufficient research to identify the key factors and related mechanisms of elderly health. This issue focused on the functional ability, intrinsic capacity and disease outcomes of the elderly, carried out analysis and research by using the data of national representative cohort and key areas, and made a series of explorations on the important factors and possible mechanisms of the elderly health, so as to provide scientific evidence for coping with population aging and health in China.

[Association between sleep duration and activity of daily living in the elderly aged 65 years and older in China].

Objective: To investigate the association between sleep duration and activity of daily living (ADL) in the elderly aged 65 years and older in China. Methods: A total of 11 247 subjects aged 65 and above were included in the Chinese Elderly Health Factors Tracking Survey from March 29, 2005 to April 8, 2019. Self-made questionnaire was used to collect the data of population sociological characteristics, health status and disease status. ADL status was assessed by basic activities of daily living. The association between sleep duration and ADL impairment was assessed by Cox proportional risk regression model. The dose-response relationship between sleep duration and ADL impairment was analyzed using restricted cubic spline function. Results: The age of the subjects was (79±10) years, including 5 793(51.5%) females. The incidence of ADL impairment was 33.3% (3 747/11 247). Subjects were divided into short, medium, and long sleep groups according to sleep duration of fewer than seven hours, seven to eight hours, or more than eight hours. The number of short, medium and long sleepers was 2 974 (26.4%), 4 922 (43.8%) and 3 351(29.8%), respectively. The intermediate sleep group had the lowest incidence of impaired ADL (4.98/100 person-years). Cox proportional risk regression model analysis showed that: taking the intermediate sleep group as reference, after adjustment of gender, age, marital status, educational level, place of residence, living with family, smoking, drinking, exercise, frequency of fruit consumption, vegetable intake frequency, sleep quality, factors such as hypertension, diabetes, heart disease and cerebrovascular disease, the long sleep time increased the risk of impaired ADL [HR (95%CI): 1.148 (1.062-1.241)]. Subgroup analysis showed a weak positive multiplicative interaction between sleep duration and age [HR (95%CI): 1.004 (1.000-1.009)], but no multiplicative interaction between sleep duration and sex [HR(95%CI): 0.948 (0.870-1.034)]. Longer sleep duration increased the risk of ADL impairment in women [HR (95%CI): 1.195 (1.074-1.329)], but not in men [HR (95%CI): 1.084 (0.966-1.217)]. Longer sleep duration increased the risk of ADL impairment in people aged 80 years and older [HR (95%CI): 1.185 (1.076-1.305)], but not in people younger than 80 years [HR (95%CI): 1.020 (0.890-1.169)]. There was a non-linear dose-response relationship between sleep duration and ADL damage (P=0.007), and the risk of ADL damage was lowest when sleep duration was 7.5 h. Conclusion: Sleep duration was positively correlated with the risk of ADL impairment in the elderly in a nonlinear dose-response relationship.

[Prediction of 6-year risk of activities of daily living disability in elderly aged 65 years and older in China].

Objective: To construct an easy-to-use risk prediction tool for 6-year risk of activities of daily living(ADL) disability among Chinese elderly aged 65 and above. Methods: A total of 34 349 elderly aged 65 and above were recruited from the Chinese Longitudinal Healthy Longevity Survey. Demographic characteristics, lifestyle and chronic diseases of the elderly were collected through face-to-face interviews. The functional status of the elderly was evaluated by the instrumental activities of daily living(IADL) scale. The mental health status of the elderly was evaluated by the Mini-Mental State Examination. The height, weight, blood pressure and other information of the subjects were obtained through physical examination and body mass index(BMI) was calculated. The ADL status was evaluated by Katz Scale at baseline and follow-up surveys. Taking ADL status as the dependent variable and the key predictors were selected from Lasso regression as the independent variables, a Cox proportional risk regression model was constructed and visualized by the nomogram tool. Area under the receiver operating characteristic curve(AUC) and calibration curve were used to evaluate the discrimination and calibration of the model. A total of 200 bootstrap resamples were used for internal validation of the model. Sensitivity analysis was used to evaluate the robustness of the model. Results: The M(Q1, Q3) of subjects' age as 86(75, 94) years old, of which 9 774(46.0%) were males. A total of 112 606 person-years were followed up, 4 578 cases of ADL disability occurred and the incidence density was 40.7/1 000 person-years. Cox proportional risk regression model analysis showed that older age, higher BMI, female, hypertension and history of cerebrovascular disease were associated with higher risk of ADL disability [HR(95%CI) were 1.06(1.05-1.06), 1.05(1.04-1.06), 1.17(1.10-1.25),1.07(1.01-1.13) and 1.41(1.23-1.62), respectively.]; Ethnic minorities, walking 1 km continuously, taking public transportation alone and doing housework almost every day were associated with lower risk of ADL disability [HR(95%CI): 0.71(0.62-0.80), 0.72(0.65-0.80), 0.74(0.68-0.82) and 0.69(0.64-0.74), respectively]. The AUC value of the model was 0.853, and the calibration curve showed that the predicted probability was highly consistent with the observed probability. After excluding non-intervening factors(age, sex and ethnicity), the AUC value of the model for predicting the risk of ADL disability was 0.779. The AUC values of 65-74 years old and 75 years old and above were 0.634 and 0.765, respectively. The AUC values of the model based on walking 1 km continuous and taking public transport alone in IADL and the model based on comprehensive score of IADL were 0.853 and 0.851, respectively. Conclusion: The risk prediction model of ADL disability established in this study has good performance and robustness.

[Association between urinary arsenic levels and anemia among older adults in nine longevity areas of China].

Objective: To investigate the association between urinary arsenic levels and anemia among older adults in nine longevity areas of China. Methods: A total of 1 896 subjects aged 65 years and above who participated in the Healthy Aging and Biomarkers Cohort Study (HABCS) in 2017-2018 were included. A self-made questionnaire was used to collect demographic characteristics, lifestyle and other information from the subjects. Through physical examination, data including height, weight and blood pressure were determined and body mass index (BMI) was calculated. Blood and urine samples were collected for the detection of hemoglobin (Hb), blood glucose, blood lipids, plasma vitamin B12 and urinary arsenic concentrations. The urinary arsenic levels were divided into four groups according to the quartiles of urinary arsenic concentrations (µg/g creatinine): Q1 (<18.7), Q2 (18.7-34.5), Q3 (34.6-69.5) and Q4(≥69.6). Multivariate logistic regression model and restricted cubic spline fitting logistic regression model were used to analyze the association between urinary arsenic levels and anemia. Results: The age of the 1 896 subjects (M (Q1, Q3)) was 83 (74, 92) years, including 952 females (50.21%), and the concentration of Hb (M (Q1, Q3)) was 135 (124, 147)g/L. The prevalence of anemia was 24.89% (472 cases). The geometric mean and M (Q1, Q3) of urinary arsenic concentrations were 37.5 and 34.6 (18.7, 69.6)µg/g creatinine, respectively. Multivariate logistic regression model analysis showed that after adjusting for age, gender, BMI, education level, smoking and drinking status, residence, economic level, ethnicity, the status of vitamin B12 deficiency, consumption frequency of aquatic products and meat, the prevalence of hypertension, diabetes and dyslipidemia, urinary arsenic levels were positively associated with anemia (Taking group Q1 as a reference, OR (95%CI) values in Q2, Q3 and Q4 groups were 1.73 (1.20-2.50), 2.08 (1.43-3.02) and 1.52 (1.02-2.28), respectively). The results of restricted cubic spline fitting logistic regression analysis showed a non-linear association between urinary arsenic concentrations and anemia (P<0.001). Subgroup analysis showed there was a negative multiplicative interaction between the prevalence of chronic diseases and urinary arsenic levels with OR (95%CI) was 0.55 (0.30-0.99), while no multiplicative interaction was found between age, gender, residence, smoking status, drinking status and urinary arsenic levels (P>0.05). There was a positive association between urinary arsenic levels and anemia in participants who were absence of chronic diseases,male, living in rural, smoking and drinking with OR (95%CI) values of 3.62 (1.30-10.06),2.46 (1.34-4.52), 1.70 (1.03-2.80), 2.21 (1.01-4.82) and 2.79 (1.23-6.33), respectively. Conclusion: There is a positive association between urinary arsenic levels and anemia among older adults in nine longevity areas of China.