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.

Cognitive Benefit of a Multidomain Intervention for Older Adults at Risk of Cognitive Decline: A Cluster-Randomized Controlled Trial.

OBJECTIVE: We sought to assess cognitive benefits of a community-based multidomain intervention for improving cognition among older adults at risk of cognitive decline (COMBAT). DESIGN: A two-armed cluster-randomized controlled trial. SETTING AND PARTICIPANTS: Community-dwelling older adults aged 60 years or older and were at risk of cognitive decline (n = 209). INTERVENTION: In this 9-month intervention study, 10 community hospitals in Beijing, China, were randomized (1:1) to receive either a multidomain intervention of meditation, cognitive training, exercise, and nutrition counseling or usual care. The intervention was delivered with weekly 1-hour group training sessions and weekly home homework. MEASUREMENTS: Primary outcome was change in cognition as measured by a composite Z score of seven cognitive tests. Secondary outcomes included subjective cognitive abilities, positive and negative affective experiences, physical activity, and dietary habits. Assessments were administered at baseline, end of the intervention, and 1 year after completing the intervention (1-year follow-up). RESULTS: Immediately after the intervention, the intervention group showed significant enhancement in cognitive performance (p = 0.026). The between-group difference in the Z score of change of cognition was 0.20 (95% CI: 0.053, 0.35), with a Hedges' g of 0.40 (95% CI: 0.29, 0.50). However, this cognitive benefit was not significant at 1-year follow-up. CONCLUSION: This multidomain intervention was effective to improve cognition for at-risk individuals. Long-term effects on cognitive function and individual differences in response to the intervention deserve further investigation.

Smoking cessation in late life is associated with increased risk of all-cause mortality amongst oldest old people: a community-based prospective cohort study.

OBJECTIVE: we aimed to investigate the association of smoking cessation with risk of all-cause mortality amongst oldest old people (aged ≥ 80 years). DESIGN: this was a prospective cohort study. SETTING: the Chinese Longitudinal Healthy Longevity Survey, implemented in 23 provinces of China. PARTICIPANTS: a total of 28,643 community-dwelling oldest old people (mean age, 92.9 ± 7.5 years) were included. METHODS: in this community-based cohort study, Cox proportional hazards models were used to examine the association of smoking cessation with risk of all-cause mortality. RESULTS: during 136,585 person-years of follow-up from baseline to 1 September 2014, compared with never smokers, hazard ratios and 95% confidence intervals for all-cause mortality were 1.06 (1.02-1.10) for current smokers, 1.23 (1.09-1.39) for transient quitters (≤1 consecutive years since smoking cessation), 1.22 (1.12-1.32) for recent quitters (2-6 consecutive years since smoking cessation) and 1.11 (1.02-1.22) for long-term quitters (>6 consecutive years since smoking cessation). Cox models with penalised splines revealed an increased risk of all-cause mortality after smoking cessation; the highest mortality risk was observed within 2-4 years after smoking cessation and the risk gradually decreased with duration of smoking cessation. We further conducted subgroup analyses and sensitivity analyses to reduce the impact of reverse causation. CONCLUSIONS: smoking is harmful to health in all populations. Our study findings indicated smoking cessation in late life to be associated with increased risk of all-cause mortality amongst oldest old people who have smoked for a long time.

Number of natural teeth, denture use and mortality in Chinese elderly: a population-based prospective cohort study.

BACKGROUND: The associations between the number of natural teeth/denture use and all-cause mortality remain unclear due to lake of investigation for the potential interaction between tooth loss and denture use and for the potential changes in these exposures over time in older adults. We undertake this study to evaluate the associations of the number of natural teeth and/or denture use with mortality in Chinese elderly. METHODS: This is a prospective cohort study of 36,283 older adults (median age: 90). The number of natural teeth and denture use were collected with structured questionnaire. We evaluated hazard ratios (HRs) and confidence intervals (CIs) using a Cox proportional hazards model adjusting for demographic factors, education, income, lifestyle factors, and comorbidities. RESULTS: We documented 25,857 deaths during 145,947 person-years of observation. Compared to those with 20+ teeth, tooth loss was associated with a gradual increase in mortality, with an adjusted HR of 1.14 (95% CI, 1.06 to 1.23) for those with 10-19 teeth, 1.23 (95% CI, 1.15 to 1.31) for those with 1-9 teeth, and 1.35 (95% CI, 1.26 to 1.44) for those without natural teeth. Denture use was associated with lower risk of mortality (adjusted HR 0.81; 95% CI, 0.77 to 0.84). Subgroup analyses indicated that the benefit of denture use was greater in men than in women (P = 0.02) and tended to decrease with age (P < 0.001). The effects of denture use did not differ among various degrees of tooth loss (P = 0.17). CONCLUSIONS: Tooth loss was associated with an increased risk of mortality in older adults. Denture use provided a protective effect against death for all degrees of tooth loss however, this effect appeared to be modified by sex and age.

Plasma 25-Hydroxyvitamin D Concentrations Are Inversely Associated with All-Cause Mortality among a Prospective Cohort of Chinese Adults Aged ≥80 Years.

BACKGROUND: High concentrations of plasma 25-hydroxyvitamin D [25(OH)D], a marker of circulating vitamin D, have been associated with a lower risk of mortality in epidemiologic studies of multiple populations, but the association for Chinese adults aged ≥80 y (oldest old) remains unclear. OBJECTIVE: We investigated the association between plasma [25(OH)D] concentration and all-cause mortality among Chinese adults aged ≥80 y. DESIGN: The present study is a prospective cohort study of 2185 Chinese older adults (median age: 93 y). Prospective all-cause mortality data were analyzed for survival in relation to plasma 25(OH)D using Cox proportional hazards regression models, with adjustments for potential sociodemographic and lifestyle confounders and biomarkers. The associations were measured with HR and 95% CIs. RESULTS: The median plasma 25(OH)D concentration was 34.4 nmol/L at baseline. Over the 5466 person-year follow-up period, 1100 deaths were identified. Men and women were analyzed together as no effect modification by sex was found. After adjusting for multiple potential confounders, the risk of all-cause mortality decreased as the plasma 25(OH)D concentration increased (P-trend <0.01). Compared with the lowest age-specific quartile of plasma 25(OH)D, the adjusted HRs for mortality for the second, third, and fourth age-specific quartiles were 0.72 (95% CI: 0.57, 0.90), 0.73 (95% CI: 0.58, 0.93), and 0.61 (95% CI: 0.47, 0.81), respectively. The observed associations were broadly consistent across age and other subgroups. Sensitivity analyses generated similar results after excluding participants who died within 2 y of follow-up or after further adjustment for ethnicity and chronic diseases. CONCLUSIONS: A higher plasma 25-hydroxyvitamin D concentration was associated with a reduced risk of all-cause mortality among Chinese adults aged ≥80 y. This observed inverse association warrants further investigation in randomized controlled trials testing vitamin D supplementation in this age group.

Combined associations of hs-CRP and cognitive function with all-cause mortality among oldest-old adults in Chinese longevity areas: a prospective cohort study.

BACKGROUND: Inflammatory markers, such as high sensitivity C-reactive protein (hs-CRP), and cognitive impairment (CI) are associated with mortality; CRP is related to the deterioration of CI. However, it is still unknown whether these two indices predict mortality independent of each other. Furthermore, their joint effect on all-cause mortality has not been well established, especially in oldest-old adults. METHODS: Based on data from the 2012 wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), we included 1447 oldest-old adults (mean age 84.7 years and 58.7% were female, weighted) with information on hs-CRP (stratified by a cutoff value of 3.0 mg/L) and cognition (quantified by Mini-Mental Status Examination (MMSE) scored according to the personal educational level) at baseline. Mortality was assessed in followed 2014 and 2017 waves. Cox proportional hazards regression models were used, with adjustment for hs-CRP and cognition (mutually controlled) and several traditional mortality risk factors. RESULTS: During a median follow-up period of 32.8 months (Q1-Q3, 9.7-59.0 months), 826 participants died. Hs-CRP [HR > 3.0 mg/L vs ≤ 3.0 mg/L: 1.64 (95% CI, 1.17, 2.30)] and cognition [HR CI vs normal: 2.30 (95% CI, 1.64, 3.21)] each was independent predictor of all-cause mortality, even after accounting for each other and other covariates. Monotonic and positive associations were observed in combined analyses, in which the highest mortality risk was obtained in elders with both high hs-CRP> 3.0 mg/L and CI [HR: 3.56 (95% CI, 2.35, 5.38)].The combined effects were stronger in male and younger oldest-old (aged 80-89 years). CONCLUSION: High hs-CRP and CI, both individually and jointly, were associated with increased all-cause mortality risks in Chinese oldest-old. Intervention strategies for preventing inflammation and maintaining adequate cognitive function may be more important in male and younger oldest-old for reducing mortality risk.

Associations between superoxide dismutase, malondialdehyde and all-cause mortality in older adults: a community-based cohort study.

BACKGROUND: Oxidative stress is an important theory of aging but population-based evidence has been lacking. This study aimed to evaluate the associations between biomarkers of oxidative stress, including plasma superoxide dismutase (SOD) activity and malondialdehyde (MDA), with all-cause mortality in older adults. METHODS: This is a community-based cohort study of 2224 participants (women:1227, median age: 86 years). We included individuals aged 65 or above and with plasma SOD activity and/or MDA tests at baseline. We evaluated the hazard ratios (HRs) and 95% confidence intervals (CIs) by multivariable Cox models. RESULTS: We documented 858 deaths during six years of follow-up. There was a significant interaction effect of sex with the association between SOD activity and mortality (P < 0.001). Compared with the lowest quintile, the risk of all-cause mortality was inversely associated with increasing quintiles of plasma SOD activity in women(P-trend< 0.001), with adjusted HRs for the second through fifth quintiles of 0.73 (95% CI 0.53-1.02), 0.52(95% CI 0.38-0.72), 0.53(95% CI 0.39-0.73), and 0.48(95% CI 0.35-0.66). There were no significant associations between SOD activity and mortality in men (P-trend = 0.64), and between MDA and mortality in all participants (P-trend = 0.79). CONCLUSIONS: Increased activity of SOD was independently associated with lower all-cause mortality in older women but not in men. This epidemiological study lent support for the free radical/oxidative stress theory of aging.

Interactive effects of diabetes and impaired kidney function on cognitive performance in old age: a population-based study.

BACKGROUND: The interactive effect between diabetes and impaired kidney function on cognitive impairment in older adults has not yet been reported. The aim of this study was to investigate the association of diabetes and impaired kidney function with cognitive impairment among Chinese older people living in a rural area. METHODS: This cross-sectional study included 1,358 participants (age ≥60 years; 60.5% women) in the population-based Confucius Hometown Aging Project in Shandong, China. Data on demographics, lifestyle factors, health history, use of medications, global cognitive function, and kidney function were collected through structured interviews, clinical examinations, and blood tests. We defined diabetes as a fasting plasma glucose level ≥7.0 mmol/l or use of hypoglycemic agents, impaired kidney function as glomerular filtration rate estimated from cystatin C (eGFRcys) <60 ml/min/1.73 m(2). Cognitive impairment was defined using the education-based cut-off scores of Mini-Mental State Examination (MMSE). Data were analyzed using multiple general linear and logistic regression models. RESULTS: Cognitive impairment was defined in 197 (14.5%) persons. The multi-adjusted ß coefficient of MMSE score associated with diabetes was -0.06 (95% confidence interval [CI], -0.16, 0.03); the corresponding figures associated with eGFRcys <60, 60-89.9, and ≥90 ml/min/1.73 m(2) were -0.15 (-0.28, -0.02), -0.01 (-0.10, 0.08), and 0 (reference) (Ptrend = 0.046), respectively. Diabetes and impaired kidney function showed an interactive effect on cognitive impairment ( interaction = 0.02). Compared with individuals having neither diabetes nor impaired kidney function, those with both conditions had a multi-adjusted odds ratio of 4.23 (95% CI, 2.10-8.49) for cognitive impairment. The relative excess risk due to interaction was 2.74. CONCLUSIONS: This study suggests that concurrent presence of diabetes and impaired kidney function is associated with a substantial likelihood for cognitive impairment in older adults.

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.

High normal plasma triglycerides are associated with preserved cognitive function in Chinese oldest-old.

OBJECTIVE: to explore the relationship between blood lipids/lipoproteins and cognitive function in the Chinese oldest-old. DESIGN: multivariate statistical analysis using cross-sectional data. SETTING: community-based setting in longevity areas in China. SUBJECTS: eight hundred and thirty-six subjects aged 80 and older were included in the sample. METHODS: plasma total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, blood pressure and fasting plasma glucose were measured and information about demographics and lifestyle was collected. Cognitive status was assessed using the Mini-Mental State Examination (MMSE). RESULTS: cumulative logit model analysis showed that triglyceride was significantly negatively associated with cognitive impairment. By general linear modelling, there was a significant linear trend of MMSE scores with the level of triglyceride, but not with levels of cholesterol after adjustment. The odds ratio (OR) of cognitive impairment (MMSE score < 18) was significantly reduced for the highest quartile of plasma triglyceride concentration (OR: 0.52, 95% CI: 0.33-0.84), but not for the second or third quartile, compared with the lowest quartile (adjusted models). There were no significant associations between cognitive impairment and cholesterol. CONCLUSION: we concluded that high normal plasma triglyceride was associated with preservation of cognitive function while lower concentrations were not in the Chinese oldest-old.

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

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

Albumin-Corrected Fructosamine Predicts All-Cause and Non-CVD Mortality Among the Very Elderly Aged 80 Years or Older Without Diabetes.

BACKGROUND: Several guidelines have suggested alternative glycemic markers for hemoglobin A1c among older adults with limited life expectancy or multiple coexisting chronic illnesses. We evaluated associations between fructosamine, albumin-corrected fructosamine (AlbF), fasting plasma glucose (FPG), and mortality in the diabetic and nondiabetic subpopulations, and compared which marker better predicts mortality among participants aged 80 and older. METHODS: Included were 2 238 subjects from the Healthy Ageing and Biomarkers Cohort Study (2012-2018) and 207 participants had diabetes at baseline. Multivariable Cox proportional hazards regression models investigated the associations of fructosamine, AlbF, FPG, and all-cause, cardiovascular disease (CVD), and non-CVD mortality in the diabetic and nondiabetic subpopulations. Restricted cubic splines explored potential nonlinear relations. C-statistic, integrated discrimination improvement (IDI), and net reclassification improvement (NRI) evaluated the additive value of different glycemic markers to predict mortality. RESULTS: Overall, 1 191 deaths were documented during 6 793 person-years of follow-up. In the linear model, per unit increases of fructosamine, AlbF, and FPG were associated with a higher risk of mortality in nondiabetic participants, with hazard ratios of 1.02 (1.00, 1.05), 1.27 (1.14, 1.42), and 1.04 (0.98, 1.11) for all-cause mortality, and 1.04 (1.00, 1.07), 1.38 (1.19, 1.59), and 1.10 (1.01, 1.19) for non-CVD mortality, respectively. Comparisons indicated that AlbF better predicts all-cause and non-CVD mortality in nondiabetic participants with significant improvement in IDI and NRI. CONCLUSIONS: Higher concentrations of fructosamine, AlbF, and FPG were associated with a higher risk of all-cause or non-CVD mortality among the very elderly where AlbF may constitute an alternative prospective glycemic predictor of mortality.

Associations Between High-Sensitivity C-Reactive Protein and All-Cause Mortality Among Oldest-Old in Chinese Longevity Areas: A Community-Based Cohort Study.

BACKGROUND: The association between high-sensitivity C-reactive protein (hsCRP) levels and all-cause mortality for the oldest-old (aged 80 years or older) remains unclear. We aimed to investigate the associations between hsCRP concentrations and the risks of all-cause mortality, and further identify the potential modifying factors affecting these associations among the oldest-old. METHODS: This prospective, community-based cohort study included 2,206 participants aged 80 years or older (median age 93.0 years) from the Healthy Aging and Biomarkers Cohort Study. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) with 95% confidential intervals (95% CIs) for all-cause mortality according to hsCRP quartiles and recommendation for relative risk categories of hsCRP levels (< 1.0, 1.0-3.0, and > 3.0 mg/L), with adjustment for sociodemographic information, lifestyle, physical examination, medical history, and other potential confounders. RESULTS: During a median follow-up period of 3.1 years (IQR: 1.6-3.9 years), 1,106 deaths were verified. After full adjustment for potential confounders, a higher hsCRP concentration was positively associated with an increased risk of all-cause mortality (P for trend < 0.001). Compared with the lowest quartile, the fully adjusted HRs of the second, third, and fourth quartiles were 1.17 (95% CI: 0.94, 1.46), 1.28 (95% CI: 1.01, 1.61), and 1.49 (95% CI: 1.20, 1.87), respectively. The association of hsCRP with all-cause mortality was modified by smoking status (P for interaction = 0.011), an increased risk of hsCRP with all-cause mortality showed among non-current smokers (HR: 1.17; 95% CI: 1.07, 1.28), but no significance was observed in current smokers (HR: 0.83; 95% CI: 0.66, 1.18). CONCLUSIONS: Our study indicated that elevated hsCRP concentrations were associated with a higher risk of all-cause mortality among Chinese oldest-old. Future studies investigating additional factors of disease and aging processes are needed to obtain a better understanding of the mechanisms.

[Association of anemia with cognition among senior female in China].

OBJECTIVE: To explore the relationship between anemia and cognitive function among senior female aged 90 years old and above in longevity regions in China. METHODS: 383 senior female in 5 longevity areas from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) 2008 - 2009 were included in the study. The cognitive function was assessed by mini mental state examination (MMSE) scale. All subjects were administered the physical examinations and biochemical testing of blood, including the hemoglobin. The difference of cognitive function between those with and without anemia was analyzed. Logistic regression was used to analyze the relationship between anemia and cognitive function. RESULTS: The 383 subjects were divided into two groups, 141 in anemia group and 242 in group without anemia. The total score of cognitive function was 9.65 ± 9.32 in anemia group, and 13.06 ± 10.25 in group without anemia (χ(2) = 5.59, P < 0.05). The percentage of cognition impairment was 84.4% (119/141) in anemia group, and 72.3% (175/242) in group without anemia (χ(2) = 8.08, P < 0.05). In the multivariable logistic regressions, after adjustment for age, education, marital status, smoking and alcohol drinking, the risk for cognition impairment in anemia group was about twice of that in group without anemia (OR = 2.016, 95%CI: 1.185 - 3.431, P = 0.010). CONCLUSION: Anemia increases the risk of cognition impairment among senior female in Chinese longevity areas.

Prevalence and Correlates of Healthy Aging Among Elderly Aged 65 Years and Over - 6 PLADs, China, 2019.

SUMMARY: What is already known on this topic? Healthy aging among Chinese older people has low prevalence. Some sociodemographic and lifestyle factors were shown to be associated with healthy aging. What is added by this report? The age-adjusted prevalence of healthy aging in the 6 provincial-level administrative divisions (PLADs) of China is 15.8 % in 2019. County-level factors, such as the prevalence of healthy communities in a county, as well as some sociodemographic variables and physical exercise, are potential factors of healthy aging. What are the implications for public health practice? These findings showed that more targeted actions, including generalizing healthy communities and individual-level interventions, may be of great importance for healthy aging.

High Blood Uric Acid Is Associated With Reduced Risks of Mild Cognitive Impairment Among Older Adults in China: A 9-Year Prospective Cohort Study.

Background: It remains unsolved that whether blood uric acid (UA) is a neuroprotective or neurotoxic agent. This study aimed to evaluate the longitudinal association of blood UA with mild cognitive impairment (MCI) among older adults in China. Methods: A total of 3,103 older adults (aged 65+ years) free of MCI at baseline were included from the Healthy Aging and Biomarkers Cohort Study (HABCS). Blood UA level was determined by the uricase colorimetry assay and analyzed as both continuous and categorical (by quartile) variables. Global cognition was assessed using the Mini-Mental State Examination four times between 2008 and 2017, with a score below 24 being considered as MCI. Cox proportional hazards models were used to examine the associations. Results: During a 9-year follow-up, 486 (15.7%) participants developed MCI. After adjustment for all covariates, higher UA had a dose-response association with a lower risk of MCI (all P for  trend < 0.05). Participants in the highest UA quartile group had a reduced risk [hazard ratio (HR), 0.73; 95% (CI): 0.55-0.96] of MCI, compared with those in the lowest quartile group. The associations were still robust even when considering death as a competing risk. Subgroup analyses revealed that these associations were statistically significant in younger older adults (65-79 years) and those without hyperuricemia. Similar significant associations were observed when treating UA as a continuous variable. Conclusions: High blood UA level is associated with reduced risks of MCI among Chinese older adults, highlighting the potential of managing UA in daily life for maintaining late-life cognition.

Association Between Plasma 25-hydroxyvitamin D Concentrations and Incident Activities of Daily Living Disability: A Longitudinal Community-Based Cohort Study.

OBJECTIVES: A few studies of Western populations have found inconsistent results regarding the associations between vitamin D status and physical function. We explored the association between circulating vitamin D status [plasma 25-hydroxyvitamin D, 25(OH)D] and incident activities of daily living (ADL) disability among Chinese older adults. DESIGN: Community-based longitudinal cohort study. SETTING AND PARTICIPANTS: A total of 2453 men and women (median age 84.0 years) in 7 Chinese longevity areas were included. MEASURES: Cox proportional hazards regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for incident ADL, with adjustments for potential sociodemographic, and lifestyle confounders and biomarkers. Because there was a statistically significant interaction between plasma 25(OH)D and sex in relation to incident ADL, men and women were analyzed separately. RESULTS: The median concentrations of plasma 25(OH)D were 46.6 nmol/L and 36.4 nmol/L for men and women, respectively. Compared with the lowest quartile in the fully adjusted model, the HR for incident ADL disability for the highest quartile was 0.55 (95% CI 0.36-0.85) for women; for men, a null association was indicated (HRhighest vs lowest 0.61, 95% CI 0.37-1.00). However, when using the recommended circulating 25(OH)D thresholds by the US Institute of Medicine, those with vitamin D sufficiency (≥50 nmol/L) had better ADL disability prognoses than those with vitamin D deficiency (<30 nmol/L) in both sexes (men HR 0.45, 95% CI 0.28-0.72; women HR 0.58, 95% CI 0.37-0.90). CONCLUSIONS AND IMPLICATIONS: The relationship between plasma 25(OH)D concentration and incident ADL disability was sex-specific among Chinese older adults. However, participants with recommended vitamin D sufficiency may have better disability prognoses in both sexes, suggesting that the recommended 25(OH)D concentration for bone health may extend to functional outcomes such as ADL disability in Chinese older adults.

[A study on chronic diseases and other related health indicators of centenarians in longevity areas in China].

OBJECTIVE: To describe chronic diseases and other related health indicators of centenarians, compare these health indicators with other age groups in longevity areas in China. METHODS: Residents who participated in the project of Chinese Longitudinal Healthy Longevity Survey (CLHLS) conducted in 2008 - 2009 were selected from 7 Longevity Areas.2029 people aged 40 and over attended the study from March to June, 2009, including 469 aged 40 and over, 436 aged 60 and over, 346 aged 80 and over, 380 aged 90 and over, 398 centenarians. Information, including socio-demographic, were collected by self-designed questionnaire. Calibrated instruments were used by the clinical personnel who had worked over 3 years to manually check subjects' health. Venous blood and urine samples were collected for blood and urine routine test, plasma macro and trace elements test, plasma biological test, using standard methods such as instrument analysis, atomic absorption spectrometry. Data analysis was conducted using descriptive statistical methods. RESULTS: In the groups aged 40 and over, 60 and over, 80 and over, 90 and over, 100 and over, the body mass index (BMI) were (23.2 +/- 4.6), (22.1 +/- 3.7), (20.2 +/- 3.4), (20.2 +/- 3.9) and (19.1 +/- 5.0) kg/m(2) in males (F = 22.78, P < 0.01) and (23.3 +/- 4.0), (21.6 +/- 3.5), (19.7 +/- 3.9), (19.0 +/- 4.8), (18.4 +/- 3.8) kg/m(2) in females (F = 51.84, P < 0.01); the prevalence of hypertension were 38.3% (80/209), 60.8% (166/273), 63.5% (106/167), 61.8% (68/110), 54.8% (34/62) in males (chi(2) = 34.26, P < 0.01) and 32.3% (84/260), 60.1% (98/163), 69.8% (125/179), 61.5% (166/270), 58.9% (198/336) in females (chi(2) = 78.45, P < 0.01); the prevalence of diabetes were 10.5% (22/209), 12.5% (34/273), 9.0% (15/167), 18.2% (20/110), 12.9% (8/62) in males (chi(2) = 5.92, P = 0.20) and 4.2% (11/260), 15.3% (25/163), 10.1% (18/179), 12.2% (33/270), 7.4% (25/336) in females (chi(2) = 19.25, P < 0.01). In groups aged 40 and over, 90 and over, 100 and over, the superoxide dismutase (SOD) activity were (29.03 +/- 5.79), (30.93 +/- 5.39), (31.63 +/- 5.92) U/ml in males (F = 4.40, P < 0.05) and (28.27 +/- 6.25), (30.86 +/- 5.72), (31.55 +/- 5.25) U/ml in females (F = 13.13, P < 0.05); levels of plasma calcium were (3.63 +/- 1.08), (3.09 +/- 0.91), (3.34 +/- 1.07) mmol/L in males (F = 5.71, P < 0.01) and (3.84 +/- 1.02), (3.19 +/- 1.16), (3.38 +/- 1.16) mmol/L in females (F = 11.61, P < 0.01); levels of selenium were (1.44 +/- 0.86), (1.28 +/- 0.60), (1.75 +/- 0.57)micromol/L in males (F = 3.79, P < 0.05) and (1.44 +/- 0.80), (1.48 +/- 0.81), (1.78 +/- 0.80) micromol/L in females (F = 8.69, P < 0.01); levels of iron were (63.25 +/- 49.05), (71.86 +/- 54.16), (138.36 +/- 77.60) micromol/L in males (F = 22.78, P < 0.01) and (64.86 +/- 57.72), (74.56 +/- 56.93), (106.56 +/- 74.08) micromol/L in females (F = 17.88, P < 0.01); levels of copper were (23.49 +/- 12.85), (17.96 +/- 7.57), (22.33 +/- 6.89) micromol/L in males (F = 5.18, P < 0.01) and (21.52 +/- 10.63), (19.60 +/- 9.57), (22.99 +/- 8.71) micromol/L in females (F = 5.68, P < 0.01); positive rates of high-sensitivity c-reactive protein (hsCRP) were 5.5% (8/146), 24.0% (18/75), 31.3% (10/32) in males (chi(2) = 22.62, P < 0.01) and 9.8% (12/122), 19.6% (40/204), 25.1% (49/195) in females (chi(2) = 11.24, P < 0.01). CONCLUSION: The results indicate that the centenarians have lower chronic diseases risks and higher anti-oxidants activity compared with other age groups, and have a high level of nutritional elements compared with those aged 90 and over. However, it is more common for them suffering from inflammation.

[Anemia status and its relevant factors among elderly people aged above 80 years old in longevity areas in China].

OBJECTIVE: To describe the epidemiological characteristics of anemia among elderly people aged 80 years old and above in longevity areas in China and to analyze its relevant factors to the health effects. METHODS: The data used in this study came from the Chinese Longitudinal Healthy Longevity Survey, including all centenarians in 7 longevity areas, as well as randomly selected population aged 40-, 60-, 80- and 90- in the same 7 areas. A total of 1980 subjects enrolled in the study. The data of general information, eating habits and diseases history was collected by questionnaire survey. Hemoglobin, plasma macro and trace elements were gained by biochemical test. Logistic regression was used to analyze the anemia and its relevant factors. RESULTS: The prevalence of anemia of elderly people aged 40-, 60-, 80-, 90-, 100- were 16.1% (75/465), 19.1% (82/429), 41.1% (141/343), 46.2% (171/370) and 57.1% (213/373) in 7 longevity areas, which kept on a rise with the increasing of age (z = 14.7, P < 0.05). The prevalence of anemia of male aged 100 years old and above was 66.7% (38/57), which was the highest one among all elderly. Plasma Ca (2.96 mmol/L), Fe (58.22 micromol/L), Zn (28.84 micromol/L) and Cu (19.56 micromol/L) of the elderly people aged 90 years old and above in anemia group, and in control group they were 3.30 mmol/L, 78.26 micromol/L, 33.66 micromol/L, 20.62 micromol/L, respectively. The significant differences were observed between the two groups (z values were -2.95, -3.07, -2.23 and -2.16, P < 0.05). The main risk factors related to anemia were age (OR = 1.675, 95%CI: 1.554 - 1.807), followed by frequency of beans and their products intake (OR = 0.545, 95%CI: 0.435 - 0.682), waist circumference (OR = 0.567, 95%CI: 0.456 - 0.705) and frequency of meat intake (OR = 1.608, 95%CI: 1.303 - 1.983). CONCLUSION: The anemia status of oldest old people in longevity areas was severe. Higher frequency of beans and their products intake and maintaining well nutritional condition benefit for the prevention of anemia.

[Investigation and analysis of plasma trace elements of oldest elderly in longevity areas in China].

OBJECTIVE: To investigate the levels and differences of plasma selenium, manganese, iron, copper, zinc among oldest elderly in longevity areas in China. METHODS: 446 oldest elderly including 208 centenarians, 238 aged 90 and over, who lived in Xiayi county of Henan province (110 persons), Zhongxiang city of Hubei province (111 persons), Mayang county of Hunan province (60 persons), Sanshui district of Guangdong province (113 persons), Yongfu county of Guangxi Zhuang autonomous region (52 persons) in China, were selected. The contents of plasma selenium, manganese, iron, copper, zinc were detected and compared among these elderly who were classified into different genders, different regions and different age groups. RESULTS: In oldest elderly, the median (inter-quartile range) of content of plasma selenium was 1.44 (0.91) micromol/L, content of manganese was 0.54 (0.94) micromol/L, content of iron was 69.17 (102.85) micromol/L, content of copper was 20.19 (8.73) micromol/L, content of zinc was 31.66 (32.51) micromol/L. Contents of plasma selenium of oldest elderly in Xiayi, Zhongxiang, Mayang, Sanshui, Yongfu region were 1.46 (0.66), 1.30 (0.80), 1.06 (0.51), 2.39 (1.53) and 1.35(0.55) micromol/L; contents of plasma manganese were 0.56 (0.51), 1.40 (1.11), 0.35 (0.71), 0.44 (0.55) and 0.15 (0.21) micromol/L; contents of plasma iron were 86.77 (86.87), 141.42 (101.83), 38.88 (36.28), 31.38 (46.19) and 79.64 (75.34) micromol/L; contents of plasma copper were 22.16 (8.11), 19.46 (9.26), 21.36 (12.38), 18.12 (6.74) and 21.47 (7.85) micromol/L; contents of plasma zinc were 36.85 (26.18), 36.59 (35.94), 39.98 (56.91), 25.05 (24.92) and 16.74 (16.81) micromol/L. Contents of plasma trace elements among oldest elderly in different longevity areas were significantly different (F values were 29.76, 38.75, 47.18, 11.51 and 13.47, P values were all less than 0.05). Contents of plasma trace elements in different gender groups (contents of plasma selenium were 1.38 (0.83) micromol/L in male and 1.45 (0.91) micromol/L in female; contents of plasma manganese were 0.52 (0.95) and 0.54 (0.91) micromol/L; contents of plasma iron were 69.23 (104.06) and 69.11 (101.05) micromol/L; contents of plasma copper were 20.28 (8.72) and 20.06 (8.76) micromol/L; contents of plasma zinc were 28.39 (32.58) and 31.85 (34.26) micromol/L) were not significantly different (t(Se) = -1.82, P = 0.07; t(Mn) = 0.64, P = 0.52; t(Fe) = 0.65, P = 0.52; t(Cu) = -1.90, P = 0.06; t(Zn) = -0.96, P = 0.34). The contents of plasma selenium, iron, copper in centenarians were higher than those aged 90 and over (contents of plasma selenium were 1.63 (0.94) micromol/L and 1.30 (0.82) micromol/L, contents of plasma iron were 112.63 (119.78) and 60.13 (58.43) micromol/L, contents of plasma copper were 21.07 (9.03) and 18.81 (8.86) micromol/L, F value were 41.99, 27.32, 24.45, P values were less than 0.01). Content of plasma manganese in centenarians was lower than those aged 90 and over (0.44 (0.76) and 0.64 (0.93) micromol/L, F = 10.76, P < 0.01). No significant differences were detected in plasma zinc between concentration and those aged 90 and over (31.78 (34.06) and 31.11 (33.85) micromol/L; F = 1.32, P = 0.25). CONCLUSION: The concentrations of plasma selenium, manganese, iron, copper and zinc were high in oldest elderly in the longevity areas. The contents of plasma selenium, iron, copper increased with age.