Residential Greenness and Frailty Among Older Adults: A Longitudinal Cohort in China

Enhancing the convenience of frailty index assessment for elderly Chinese people with machine learning methods

Frailty is a state that is closely associated with adverse health outcomes in the aging process. The frailty index (FI), which measures frailty in terms of cumulative deficits, has been widely used for frailty assessment in elderly people, and its advantage of self-reported information collection makes it applicable to a broader group of elderly people. Our study aims to simplify the Frailty Index Assessment Scale, while maintaining its reliability and accuracy, to easily and quickly assess frailty in elderly people. In this study, participants (age ≥ 65 years) from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), which had 13,339, 372 and 1214 participants in 2008, 2011, and 2014, respectively, were used. The 2008 dataset was split into 80% for training and 20% for internal validation, and the data from 2011 to 2014 as external validation. In order to obtain effective predictors, we used Lasso regression, Boruta algorithm and random forest classifier score for feature selection. We used six models for predictive model construction and evaluated the models in the validation dataset. Model performance was measured by area under the curve (AUC), accuracy and F1 score. Logistic regression was found to be the best performing and most interpretable algorithm with AUC, accuracy and F1 of 0.974, 0.932 and 0.880 for the validation dataset, respectively. The AUCs for the external independent validation dataset were 0.963 and 0.977, respectively. Subgroup analysis showed that the model had good predictive power in both males and females. The predictive power was stronger among the elderly people over 80 years old, with AUC, accuracy and F1 of 0.973,0.914, and 0.893, respectively. The model also obtained good predictive power in the case of FI measured by different indicators. The model showed good robustness in the follow-up assessment of frailty status in elderly people, with the AUC remaining above 0.95 and accuracy above 0.9 over the long-term follow-up. Using machine learning techniques, we have successfully developed a simple frailty assessment prediction model based on 10 key features to shorten the frailty assessment scale with near full-scale accuracy. A user-friendly website was created to facilitate the application of this prediction model ( https://healthy-aging.shinyapps.io/Frailty_Assessment/ ).

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

BACKGROUND

Dietary diversity has been suggested as a potential preventive measure against frailty in older adults, but the effect of changes in dietary diversity on frailty is unclear. This study was conducted to examine the association between the dietary diversity score (DDS) and frailty among older Chinese adults.

METHODS

A total of 12,457 adults aged 65 years or older were enrolled from three consecutive and nonoverlapping cohorts from the Chinese Longitudinal Healthy Longevity Survey (the 2002 cohort, the 2005 cohort, and the 2008 cohort). DDS was calculated based on nine predefined food groups, and DDS changes were assessed by comparing scores at baseline and the first follow-up survey. We used 39 self-reported health items to assess frailty. Cox proportional hazard models were performed to examine the association between DDS change patterns and frailty.

RESULTS

Participants with low-to-low DDS had the highest frailty incidence (111.1/1000 person-years), while high-to-high DDS had the lowest (41.1/1000 person-years). Compared to the high-to-high group of overall DDS pattern, participants in other DDS change patterns had a higher risk of frailty (HRs ranged from 1.25 to 2.15). Similar associations were observed for plant-based and animal-based DDS. Compared to stable DDS changes, participants with an extreme decline in DDS had an increased risk of frailty, with HRs of 1.38 (1.24, 1.53), 1.31 (1.19, 1.44), and 1.29 (1.16, 1.43) for overall, plant-based, and animal-based DDS, respectively.

CONCLUSIONS

Maintaining a lower DDS or having a large reduction in DDS was associated with a higher risk of frailty among Chinese older adults. These findings highlight the importance of improving a diverse diet across old age for preventing frailty in later life.

Urban heatwave, green spaces, and mental health: A review based on environmental health risk assessment framework

Utilizing the framework of environmental health risk assessment and healing, the article reviews the effectiveness and potential of green space systems in mitigating the impact of high temperatures, promoting mental health, and improving the risk characteristics of high-temperature heat waves. We utilized CiteSpace software to conduct a time-zone analysis of the relationship between heatwaves, green spaces, and health using clustered data from 2001 to 2023. This study evaluates the role of green space systems in mitigating high temperatures and enhancing mental health within the environmental health risk assessment framework. Using CiteSpace software, we analyzed literature from 2001 to 2023, focusing on the interactions among heatwaves, green spaces, and health. Our results indicate that most existing research concentrates on hazard identification, with insufficient exploration of the dose-response relationships between green spaces and temperature reduction. Quantitative studies on green space design and spatial optimization are scarce, and guidance on effective configurations remains limited. Additionally, the health impacts of heatwaves vary by region, with a noticeable imbalance in research focus; Asia and Africa, in particular, are underrepresented in studies addressing heatwave effects. We conclude that effective mitigation strategies require: (1) a comprehensive environmental health risk assessment framework that integrates advanced methods like big data analysis and geospatial simulations to improve green space planning and design; (2) further theoretical exploration into the mechanisms by which green spaces regulate temperature and mental health, including detailed analysis of spatiotemporal patterns and the functional optimization of green space structures; and (3) the development of robust parameterized design guidance based on specific therapeutic dosages (green space stimulus) to optimize configurations and enhance the effectiveness of green spaces in mitigating adverse mental health impacts from deteriorating thermal environments. Future research should prioritize underrepresented regions, focusing on exposure levels, dose-response relationships, and high-temperature warning systems while fostering multidisciplinary collaboration to develop effective urban planning and climate adaptation strategies.

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

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

Exposure to green spaces, cardiovascular risk biomarkers and incident cardiovascular disease in older adults: The Seniors-Enrica II cohort

INTRODUCTION

The impact of residential green spaces on cardiovascular health in older adults remains uncertain.

METHODS

Cohort study involving 2114 adults aged ≥ 65 years without cardiovascular disease (CVD), residing in five dense municipalities (Prince et al., 2015) of the Madrid region and with detailed characterization of their socioeconomic background, health behaviors, CVD biological risk factors, and mental, physical, and cognitive health. Greenness exposure was measured using the Normalized Difference Vegetation Index (NDVI) at varying distances from participants' homes. Traffic exposure, neighborhood environment, neighborhood walkability, and socioeconomic deprivation at the census level were also assessed. Serum N-terminal pro-B-type natriuretic peptide (NT-ProBNP), high-sensitivity troponin T (hs-TnT), interleukin 6 (IL-6), and Growth Differentiation Factor 15 (GDF-15) were measured at baseline, and incident CVD events identified through electronic medical records (International Classification of Primary Care-2 codes K74, K75, K77, K90, and K92).

RESULTS

After adjusting for sex, age, educational attainment, financial hardship and socioeconomic deprivation at the census level, an interquartile range (IQR) increase in NDVI at 250, 500, 750, and 1000 m around participants' homes was associated with mean differences in ProBNP of -5.56 % (95 %CI: -9.77; -1.35), -5.05 % (-9.58; -0.53), -4.24 % (-8.19, -0.19), and -4.16 % (-7.59; -0.74), respectively; and mean differences in hs-TnT among diabetic participants of -8.03 % (95 %CI: -13.30; -2.77), -9.52 % (-16.08; -2.96), -8.05 % (-13.94, -2.16) and -5.56 % (-10.75; -0.54), respectively. Of similar magnitude, although only statistically significant at 250 and 500 m, were the observed lower IL-6 levels with increasing greenness. GDF-15 levels were independent of NDVI. In prospective analyses (median follow-up 6.29 years), an IQR increase in residential greenness at 500, 750, and 1000 m was associated with a lower risk of incident CVD. The variables that contributed most to the apparent beneficial effects of greenness on CVD were lower exposure to traffic, improved cardiovascular risk factors, and enhanced physical performance. Additionally, neighborhood walkability and increased physical activity were notable contributors among individuals with diabetes.

CONCLUSION

Increased exposure to residential green space was associated with a moderate reduction in CVD risk in older adults residing in densely populated areas.

Assessing the effects of air pollution and residential greenness on frailty in older adults: a prospective cohort study from China

Many studies have established a correlation between air pollution and green space with age-related diseases, yet the relationship between air pollution, green space, and frailty among older adults is not fully understood. The primary objective of this investigation is to examine the longitudinal association among air pollution, green space, and frailty in older adults, as well as the potential interaction and mediating effect. Analyzed data were obtained from the multi-wave CLHLS investigation (2008-2018). The participants' environmental exposure was evaluated using six air pollutants (PM1, PM2.5, PM10, PM10-2.5, O3, and NO2), and normalized difference vegetation index (NDVI). Annual ambient air pollutants were estimated using satellite-based spatiotemporal models. Time-varying Cox proportional risk models were employed to investigate the longitudinal relationships between air pollutants, greenness, and the onset of frailty in the elderly population. We conducted a variety of subgroup analyses, sensitivity analyses, and assessed potential interaction and causal mediating effects. A total of 6953 eligible elderly individuals were enrolled in our study. In the fully adjusted model, per IQR uptick in levels of PM1, PM2.5, PM10, PM10-2.5, O3, and NO2 corresponded to a 17% (95% CI 1.10-1.24), 25% (95% CI 1.17-1.34), 29% (95% CI 1.20-1.39), 35% (95% CI 1.24-1.47), 12% (95% CI 1.04-1.20), and 11% (95% CI 1.05-1.18) increase in frailty risk, respectively. For NDVI, increased IQR was significantly negatively associated with the risk of frailty (aHR 0.82, 95% CI 0.77-0.87). Our results revealed a significant interaction effect among O3, NO2, and residential greenness. PM1, PM2.5, PM10, and PM10-2.5 play a mediating role in the estimated relationship between residential greenness and frailty. In summary, our study reveals that PM1, PM2.5, PM10, PM10-2.5, O3, and NO2 correspond to elevated risks of frailty in the elderly. Residential greenness is associated with a lower risk of frailty in the elderly. Residential greenness can exert a positive impact on frailty by reducing particulate matter concentrations.

Dietary factors in relation to the risk of cognitive impairment and physical frailty in Chinese older adults: a prospective cohort study

PURPOSE

The study aimed to investigate the independent associations of dietary factors with cognitive impairment (CI) and physical frailty (PF) among Chinese older adults.

METHODS

This study included 10,734 participants (mean age = 78.7 years) free of CI and PF at baseline from the Chinese Longitudinal Health Longevity Survey. Dietary intake was collected using a simplified food frequency questionnaire every 3-4 years. The Chinese version Mini-Mental State Examination was used to assess cognition function, participants with a score below 18 were defined as CI. PF was defined using the activities of daily living, instrumental activities of daily living, and functional limitation-related questions. The outcome was defined as the first onset of either CI or PF. Competing risk models were used to estimate the corresponding hazard ratios (HRs) and the 95% confidence intervals (95% CIs).

RESULTS

During the study follow-up (mean = 8.1 years), a total of 1220 CI cases and 1451 PF cases were newly identified. Higher frequency of fruits intake was associated with a lower hazard of CI (HR = 0.75, 95% CI 0.58-0.97), whereas higher intake of preserved vegetables demonstrated an opposite association (HR = 1.23, 95% CI 1.07-1.42). In terms of PF, we observed a lower risk associated with higher meat and poultry intake (HR = 0.72, 95% CI 0.61-0.88). In particular, a significant protective association of fish and aquatic products intake with PF was observed among participants with ≥ 28 natural teeth (HR = 0.52, 95% CI 0.27-0.99).

CONCLUSION

Our findings suggest divergent roles of major dietary factors in the development of CI and PF among Chinese older adults.

Plant-Based Diet Indices and Their Association with Frailty in Older Adults: A CLHLS-Based Cohort Study

Within the realm of aging, the nexus between diet and health has garnered considerable attention. However, only select studies have amalgamated insights into the correlation between plant and animal food consumption and frailty. Our aim was to appraise the connections between the overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI) and frailty in the elderly, utilizing data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). This cohort study drew upon CLHLS data spanning from 2008 to 2018. The PDI, hPDI, and uPDI were gauged using a simplified food frequency questionnaire (FFQ). A frailty index, encompassing 35 variables across major health domains, was formulated. Cox proportional hazard models were employed to scrutinize the associations between the three plant-based dietary indices and frailty in older adults, including an exploration of gender disparities in these associations. A cohort of 2883 study participants was encompassed, with 1987 (68.9%) observed to be either frail or in the pre-frail stage. The Cox model with penalized spline exhibited linear associations of PDI, hPDI, and uPDI with the frailty index. Following covariate adjustments, it was discerned that older adults situated in the highest quartiles of PDI (HR = 0.86, 95% CI: 0.77-0.95) and hPDI (HR = 0.83, 95% CI: 0.74-0.93) experienced a 14% and 17% diminished risk of frailty compared to those in the lowest quartiles of PDI and hPDI, respectively. Conversely, when contrasted with those in the lowest quartile of uPDI, older adults adhering to the highest tertile of uPDI exhibited a 21% elevated risk of frailty (HR = 1.21, 95% CI: 1.08-1.36), with both associations achieving statistical significance (p < 0.01). Moreover, additional subgroup analyses revealed that the protective effects of PDI and hPDI against frailty and the deleterious effects of uPDI were more conspicuous in men compared to women. To forestall or decelerate the progression of frailty in the elderly, tailored dietary interventions are imperative, particularly targeting male seniors.

China's public health initiatives for climate change adaptation

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

Recent developments in frailty identification, management, risk factors and prevention: A narrative review of leading journals in geriatrics and gerontology

Frailty is an age-related clinical condition characterised by an increased susceptibility to stressors and an elevated risk of adverse outcomes such as mortality. In the light of global population ageing, the prevalence of frailty is expected to soar in coming decades. This narrative review provides critical insights into recent developments and emerging practices in frailty research regarding identification, management, risk factors, and prevention. We searched journals in the top two quartiles of geriatrics and gerontology (from Clarivate Journal Citation Reports) for articles published between 01 January 2018 and 20 December 2022. Several recent developments were identified, including new biomarkers and biomarker panels for frailty screening and diagnosis, using artificial intelligence to identify frailty, and investigating the altered response to medications by older adults with frailty. Other areas with novel developments included exercise (including technology-based exercise), multidimensional interventions, person-centred and integrated care, assistive technologies, analysis of frailty transitions, risk-factors, clinical guidelines, COVID-19, and potential future treatments. This review identified a strong need for the implementation and evaluation of cost-effective, community-based interventions to manage and prevent frailty. Our findings highlight the need to better identify and support older adults with frailty and involve those with frailty in shared decision-making regarding their care.

Is waist-calf circumference ratio associated with frailty in older adults? Findings from a cohort study

BACKGROUND

The waist-calf circumference ratio (WCR) has been suggested as a potential indicator of visceral adiposity. Nevertheless, the relationship between WCR and the risk of frailty remains unclear. Therefore, our study aimed to investigate the association between WCR and longitudinal changes in WCR with frailty risk in older adults.

METHODS

We included 2359 participants aged ≥ 65 years without frailty (frailty index [FI] ≤ 0.21) from the Chinese Longitudinal Healthy Longevity Survey in the 2014 wave. The follow-up was conducted in 2018. We investigated the relationship of WCR, waist circumference (WC), and calf circumference (CC) with frailty using both the Cox proportional hazards model and the generalized estimating equation (GEE).

RESULTS

During a median follow-up of 4.0 years, 668 (28.2%) frailty occurred. Those with higher WCR and WC had a significantly increased risk of frailty (fifth quintile compared with first quintile: hazard ratio [HR] = 1.59, 95% confidence interval [CI] 1.24-2.04 for WCR; HR = 1.69, 95% CI 1.27-2.24 for WC), whereas those in the fourth quintile of CC had a lower likelihood of developing frailty compared to those in the first quintile (HR = 0.67, 95% CI 0.50-0.89). Interaction analyses showed that the effects of WCR on frailty were more pronounced in females (P-interaction = 0.016). GEE analyses revealed that increased WCR and WC were associated with a higher risk of frailty (odds ratio [OR] = 1.74, 95% CI 1.43-2.12 for WCR; OR = 1.03, 95% CI 1.02-1.04 for WC), while CC showed opposite results (OR = 0.95, 95% CI 0.93-0.97).

CONCLUSIONS

A higher WCR and WC, as well as a lower CC, were significantly associated with higher frailty. Of these measures, WCR demonstrated the strongest association with frailty, suggesting that having a combination of high central fat and low lean body mass may increase the risk of developing frailty.

Dietary diversity and frailty among older Chinese people: evidence from the Chinese Longitudinal Healthy Longevity Study

BACKGROUND

Dietary diversity is widely advocated as a means to promote health, but little is known regarding whether the beneficial effects still apply in older adults.

OBJECTIVE

To examine the association between the dietary diversity score (DDS) and frailty among older Chinese adults.

METHODS

A total of 13,721 adults aged ≥65 y without frailty at baseline were enrolled. The DDS at baseline was constructed based on 9 items of a food frequency questionnaire. We used 39 self-reported health items to construct a frailty index (FI), with FI ≥ 0.25 indicating frailty. Cox models with restricted cubic splines were used to evaluate the dose-response relationships of DDS (continuous) with frailty. In addition, Cox proportional hazard models were used to examine the association between DDS (categorized as scores ≤4, 5-6, 7, and ≥8) and frailty.

RESULTS

During the mean follow-up of 5.94 y, 5250 participants met the criteria for frailty. Each 1-unit increase in DDS corresponded to a 5% lower risk of frailty (hazard ratio [HR]; 0.95; 95% CI: 0.94, 0.97]. Compared with participants with DDS ≤4 points, those with a DDS of 5-6, 7, and ≥8 points exhibited a lower frailty risk, with HRs of 0.79 (95% CI: 0.71, 0.87), 0.75 (95% CI: 0.68, 0.83), and 0.74 (95% CI: 0.67, 0.81), respectively (P-trend < 0.001). Protein-rich food items, such as meat; eggs; and beans, were associated with protective effects against frailty. In addition, a significant association was observed between higher consumption of 2 high-frequency foods, tea and fruits, and lower risk of frailty.

CONCLUSIONS

A higher DDS was associated with a lower risk of frailty among older Chinese adults. This study highlights the importance of a diverse diet as a potential modifiable behavioral factor for preventing frailty in older Chinese adults.

Effects of functional limitations and activities of daily living on the mortality of the older people: A cohort study in China

Introduction

Prevalence of functional limitations (FLs) and disabled activities of daily living (ADL) cause heavy burdens to the health of the older people. Stratified by gender, this study aimed to explore the effects of FL and ADL on the mortality of the older people in China, and the mechanism was then discussed.

Methods

We used survey data of a prospective 10-year cohort (2008-2018), from the China Longitudinal Healthy Longevity Survey (CLHLS). The primary outcome was all-cause mortality, and Independent variables included FL, basic ADL (BADL), and instrumental ADL (IADL). Covariates involved socio-demographic characteristics, health-related behaviors, and health status of the participants in the CLHLS project.

Results

There were 967 (19.20%) male and 2,235 (32.36%) female older people performed functional limitations, and their survival time was 60.98 (SE = 0.66) and 55.19 (SE = 0.55) months, respectively. Old adults with FL had significantly poorer survival than the ones without (Log-rank test, P < 0.001). Weibull regression suggested that FL (P < 0.001), abnormal BADL (P < 0.001) and IADL (P < 0.001) were negatively associated with the survival of the older people. Further analysis showed that BADL and IADL performed significantly mediating roles in the relation of FL and survival time in old adults; additionally, for female older people, BADL also exhibited a significant moderating role in the effect of FL on survival.

Conclusions

Prevalence of FL was serious among the older people in China, especially for the women. Disabilities of BADL and IADL and FL were negatively associated with the survival time of the older people in China. Regarding the effect of FL on survival, BADL and IADL performed significantly mediating roles, and the moderating role of BADL existed only for the female. These suggested evidence to implement strategies to maintain health in the older people.

Biomass fuel usage for cooking and frailty among older adults in China: a population-based cohort study

Background

Although outdoor air pollution is reported to have a negative effect on frailty, evidence involving household air pollution is sparse.

Methods

A cohort study on older participants aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey was conducted between 2011/2012 and 2014. Household cooking fuel types were determined by self-reported questionaries, and were dichotomized into clean or biomass fuels. The frailty status was evaluated via a 46-item frailty index (FI) and the FRAIL scale, respectively. Frailty was identified if FI >0.21 or FRAIL score ≥3. Cox proportional hazards models were employed to examine the relationship between cooking fuels and incident frailty. And the effects of swapping cooking fuels on frailty risk were also explored.

Results

Among 4,643 participants (mean age at baseline 80.9 ± 9.6 years, 53.7% male) totaling 11,340 person-years, 923 (19.9%) incident frailty was identified using FI. Compared to clean fuels, cooking with biomass fuels was intricately linked to a 23% rise in frailty risk (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.06-1.43). A similar association was detected between biomass cooking fuels and frailty measured by the FRAIL scale (HR 1.24, 95% CI 1.04-1.50). Sensitive analyses supported the independent relationship between biomass fuels and frailty. Stratified analyses revealed that the frailty risk was higher among town residents (HR 1.44, 95% CI 1.13-1.84) and participants not exercising regularly (HR 1.35, 95% CI 1.11-1.64). In comparison with persistent biomass fuels usage, switching to clean fuels had a trend to reduce the frailty risk, and the opposite effect was observed when swapping from clean to biomass fuels.

Conclusion

Cooking with biomass fuels was associated with an increased frailty risk in older adults, especially amongst those living in town and those lacking regular exercise. More studies are needed to confirm our findings and to evaluate the potential benefits of reducing indoor biomass fuel usage.

Associations between Frailty and Ambient Temperature in Winter: Findings from a Population-Based Study

Frailty is an accumulation of deficits characterized by reduced resistance to stressors and increased vulnerability to adverse outcomes. However, there is little known about the effect of ambient temperature in winter on frailty among older adults, a population segment with the highest frailty prevalence. Thus, the objective of this study is to investigate the associations between frailty and ambient temperature in winter among older adults. This study was based on the Chinese Longitudinal Healthy Longevity Survey (CLHLS) of older adults aged ≥65 years from the 2005, 2008, 2011, and 2014 waves. The 39-item accumulation of frailty index (FI) was used to assess the frailty status of the participants. The FI was categorized into three groups as follows: robust (FI ≤ 0.10), prefrail (FI > 0.10 to <0.25), and frail (FI ≥ 0.25). Generalized linear mixed models (GLMMs) were conducted to explore the associations between frailty and ambient temperature in winter. A generalized estimating equation (GEE) modification was applied in the sensitivity analysis. A total of 9421 participants were included with a mean age of 82.81 (SD: 11.32) years. Compared with respondents living in the highest quartile (≥7.5 °C) of average temperature in January, those in the lowest quartile (<−1.9 °C) had higher odds of prefrailty (OR = 1.35, 95% CI 1.17−1.57) and frailty (OR = 1.61, 95%CI 1.32−1.95). The associations were stronger among the low-education groups, agricultural workers before retirement, and non-current exercisers. Additionally, results from the GEE model reported consistent findings. Lower levels of ambient temperature in winter were associated with higher likelihoods of prefrailty and frailty. The findings on vulnerability characteristics could help improve public health practices to tailor cold temperature health education and warning information.

Calf circumference predicts frailty in older adults: the Chinese longitudinal healthy longevity survey

BACKGROUND

Although frailty is a common geriatric syndrome in old adults, a simple method to assess the degree of frailty in a person has not yet been established. In this study we have tried to establish the association between calf circumference (CC) and frailty among older Chinese people.

METHODS

We used the data obtained from the 2014 edition of the Chinese Longitudinal Healthy Longevity Survey; 1216 participants aged ≥60 years were included for the study. Body mass index, CC and waist circumference measurement data, and laboratory test results were collected. Frailty status was measured using the frailty index (FI). Participants were then classified into non-frail (FI < 0.25) and frail (FI ≥ 0.25) groups.

RESULTS

There were 874 participants (71.9%) in the non-frail group and 342 (28.1%) in the frail group. The CC was significantly different between the two groups (31.54 ± 4.16 versus 28.04 ± 4.53, P < 0.001). Logistic regression analysis revealed that CC (odds ratio = 0.947, 95% confidence interval: 0.904-0.993, P = 0.023) was an independent impact factor associated with frailty. The CC value of 28.5 cm was considered the best cut-off value in women with area under the curve (AUC) was 0.732 (P < 0.001) and 29.5 cm in men with AUC was 0.592 (P = 0.004);We created a simple prediction model for frailty that included age,sex and CC:[Formula: see text]P = e^logit(P) /1 + e^logit(P), and AUC is 0.849 (P < 0.001).

CONCLUSIONS

CC is a convenient and predictable marker of frailty in older adults.

Sociodemographic Variations in the Availability of Urban Green Spaces in an Older Swedish Population

Urban green spaces (UGS) can have a positive impact on health and thereby potentially ease the strain on the health care system. However, the availability and benefits seem to vary between different sociodemographic groups. The aim of this study was to investigate associations between sociodemographic factors and availability to UGS among people aged 65 years or older. Data on sociodemographic variables and residential coordinates were obtained for three cross-sectional cohorts in two cities (Malmö and Kristianstad) and three years (2010, 2015, and 2019). Three measures of urban green spaces; total (UGS), public (PGS) and quiet (QGS), within 300 m were used to determine availability. The results indicated higher availability to both total and publicly available urban green spaces for groups with lower socioeconomic status (SES) is positive from a health perspective. However, availability to high qualitative publicly available urban green spaces, from a noise perspective, was lower, indicating the opposite.

Greenness and the Potential Resilience to Sexual Violence: "Your Neighborhood Is Being Neglected Because People Don't Care. People With Power Don't Care"

There is increasing evidence that green space in communities reduces the risk of aggression and violence, and increases wellbeing. Positive associations between green space and resilience have been found among children, older adults and university students in the United States, China and Bulgaria. Little is known about these associations among predominately Black communities with structural disadvantage. This study explored the potential community resilience in predominately Black neighborhoods with elevated violent crime and different amounts of green space. This embedded mixed-methods study started with quantitative analysis of women who self-identified as "Black and/or African American." We found inequality in environments, including the amount of green space, traffic density, vacant property, and violent crime. This led to 10 indepth interviews representing communities with elevated crime and different amounts of green space. Emergent coding of the first 3 interviews, a subset of the 98 in the quantitative analysis, led to a priori coding of barriers and facilitators to potential green space supported community resilience applied to the final 7 interview data. Barriers were a combination of the physical and social environment, including traffic patterns, vacant property, and crime. Facilitators included subjective qualities of green space. Green spaces drew people in through community building and promoting feelings of calmness. The transformation of vacant lots into green spaces by community members affords space for people to come together and build community. Green spaces, a modifiable factor, may serve to increase community resilience and decrease the risk of violence.

Association of blood lead exposure with frailty and its components among the Chinese oldest old

Lead (Pb) is a widespread environmental contaminant, associated with a higher risk of functional impairment that can lead to frailty in older adults. However, few studies focused on the association of Pb exposure with frailty among the oldest old (aged ≥ 80 years). In this study, we aimed to assess the associations of Pb with frailty and its components in the oldest old. The included individuals were the oldest old aged ≥ 80 years who participated in a 2017 cross-sectional survey of the Healthy Aging and Biomarkers Cohort Study. Frailty was ascertained by the frailty index, which was created based on health deficits. We used logistic regression models to estimate the association of blood Pb with frailty and its components. The geometric mean and median of blood Pb were 38.51 μg/L and 36.27 μg/L among the oldest old, respectively. Compared with the first quartile of blood Pb, participants in the fourth quartile had higher risk of frailty and its components, the ORs are 1.71 (1.22-2.41), 1.99 (1.35-2.94), 1.91 (1.25-2.93), 1.57 (1.13-2.17) and 1.43 (1.05-1.96), for frailty, ADL disability, IADL disability, functional limitations, and hearing loss in the oldest old, respectively. There was a significant interaction between blood Pb and frailty in different age groups. In conclusion, our findings provide preliminary evidence that higher blood Pb may increase the risk of frailty among the oldest old by increasing the risk of disability in four physical functions: disability in ADL, disability in IADL, functional limitations, and hearing loss.

Association between Age-Friendliness of Communities and Frailty among Older Adults: A Multilevel Analysis

An age-friendly environment is one of the measures of healthy aging. However, there is scarce evidence of the relationship between the age-friendliness of communities (AFC) and frailty status among Chinese older adults. This study aims to examine this relationship using a multilevel analysis with the data of a cross-sectional study conducted among 10,958 older adults living in 43 communities in four cities in China. The validated Age-friendly Community Evaluation Scale and Chinese frailty screening-10 Scale (CFS-10) were used to measure AFC and Frailty. Multilevel regression analyses were performed to examine the relationship between the AFC in two assessments of individual- and community-level and frailty status. After controlling for individual-level socio-demographic, health status, and lifestyle variables, compared with older adults in the lowest quartile of the individual-level perception of AFC, the frailty odds ratios for those in the top three quartiles were 0.69 (95% confidence interval [CI]: 0.56–0.83), 0.75 (95% CI: 0.61–0.91), and 0.56 (95% CI: 0.48–0.74). However, there was no association between the community-level AFC and frailty. A higher level of age-friendliness in the community is associated with lower frailty odds. Therefore, building age-friendly communities may be an important measure to prevent frailty among Chinese older adults.

Association between residential greenspace structures and frailty in a cohort of older Chinese adults

Background

Frailty is a late-life clinical syndrome resulting from the accumulation of aging-induced decline. Greenspaces measured with normalized difference vegetation index (NDVI) are protective of frailty. However, NDVI is not as informative as structure indices in describing greenspaces' constitution, shape, and connectivity measured by the largest patch index (LPI), shape index, and cohesion index representing larger, more complex, and more dense greenspaces through higher values. We aim to study the association between greenness structures and frailty in a cohort of Chinese older adults.

Methods

We included older adults from 2008-2014 China Longitudinal Healthy Longevity Survey (CLHLS). We used greenspace indices from satellite to quantify structures (area-edge, shape, proximity) at county-level, and calculated frailty index (FI) as an outcome. We did cross-sectional analyses using linear and logistical regression, and longitudinal analyses using the generalized estimating equations (GEE).

Results

Among 8776 baseline participants, mean LPI, shape, cohesion, and FI are 7.93, 8.11, 97.6, and 0.17. In cross-sectional analyses, we find negative dose-response relationships for greenspace structures and frailty, especially in females, centenarians, illiterate people, city residents, unmarried people, and individuals with increased frailty. Participants living in the highest quartile of LPI, shape, and cohesion have 32% (95%CI: 21-42%), 35% (95%CI: 24-44%), and 37% (95%CI: 26%-46%) lower odds of frailty than the lowest quartile. However, we do not find a significant association in longitudinal analyses.

Conclusions

Higher levels of greenness structures (area-edge, shape, and proximity) might be related to lower frailty, while a clear longitudinal benefit cannot be identified in this analysis.

Association between Residential Greenness and Incidence of Parkinson's Disease: A Population-Based Cohort Study in South Korea

It is widely known that exposure to residential greenness is beneficial for health. However, few studies have analyzed the association between greenery and Parkinson’s disease (PD). We selected 313,355 participants who matched the inclusion criteria from the National Health Insurance Service-National Sample Cohort, followed up from 2007 to 2015. Residential greenness, represented by the normalized difference vegetation index (NDVI), was obtained from satellite measurements. We estimated hazard ratios of PD associated with a 0.1-unit increase in long-term greenness exposure at the district level for the previous 1 year of each year until a censoring/event occurred, using time-varying Cox proportional hazard models, adjusted for individual- and area-level characteristics. During the 2,745,389 person-years of follow-up, 2621(0.8%) participants developed PD. Exposure to higher levels of residential greenness was found to be associated with a decreased risk of PD incidence (21% per 0.1-unit increase, 95% confidence interval (CI): 0.74–0.84). In subgroup analyses, stronger protective effects were observed in participants aged over 50 years, females, overweight/obese participants, non-urban residents, non-smokers, alcoholics, and those with comorbidities. Long-term exposure to greenness was beneficial to incident PD, and our findings could aid in the development of public-health strategies.

Living Preference Modifies the Associations of Living Arrangements With Loneliness Among Community-Dwelling Older Adults

Objectives

Living arrangement has been reported to have a significant influence on feelings of loneliness in older adults, but their living preferences may confound the association. This study aimed to investigate whether the associations of living arrangements with loneliness differ in community-dwelling older adults according to different living preferences.

Methods

In the 2008/2009 (baseline) and 2011/2012 (follow-up) waves of the Chinese Longitudinal Healthy Longevity Survey, living arrangements [living with children mainly (LWC), living with spouse only (LWS), and living alone (LA)], living preferences [preferring living with children (PreLWC) and preferring living alone/only with spouse (PreLA)], and feelings of loneliness were assessed. The effect modifications of living preferences in the associations of living arrangements with loneliness were estimated using logistic regression models, and corresponding odds ratios (ORs) were calculated.

Results

Living preferences significantly modified the associations of living arrangements with loneliness at baseline (p for interaction = 0.009 for LWS and = 0.015 for LA). Compared with LWC, LWS was protective for loneliness only in the PreLA older adults at baseline (OR = 0.53, 95% CI = 0.45–0.64, p &lt; 0.001), and LA was significantly associated with loneliness especially in the PreLWC older adults, compared with their PreLA counterparts (at baseline, ORs = 2.89 vs. 2.15; at follow-up, ORs = 1.68 vs. 1.51).

Conclusion

Living preference modifies the associations of living arrangements with loneliness, and those who prefer living with children but live alone are more likely to feel lonely. It is recommended that living preferences should be considered when managing loneliness in community-dwelling older adults.

Living arrangement modifies the associations of loneliness with adverse health outcomes in older adults: evidence from the CLHLS

Background

Although it has been suggested that loneliness is a risk factor for adverse health outcomes, living arrangement may confound the association. This study aimed to investigate whether the associations of loneliness with adverse health outcomes differ in community-dwelling older adults according to different living arrangements.

Methods

In the 2008/2009 wave of Chinese Longitudinal Healthy Longevity Survey, 13,738 community-dwelling older adults (≥65 years) were included for analyses. Living arrangements and loneliness were assessed. Health outcomes including cognitive and physical functions were assessed using MMSE, ADL/IADL scales and Frailty Index in the 2008/2009 and 2011/2012 waves; mortality was assessed in the 3-year follow-up from 2008/2009 to 2011/2012. The effect modificaitons of loneliness on adverse health outcomes by living arrangements were estimated using logistic regression or Cox proportional hazards regression models.

Results

Living alone older adults were significantly more likely to be lonely at baseline (52% vs 29.5%, OR = 1.90, 95% CI = 1.67–2.16, P < 0.001), compared with those living with others. Loneliness in older adults was a significant risk factor for prevalent cognitive impairment and frailty, and 3-year mortality, especially among those who lived with others (OR = 1.32, 95% CI = 1.15–1.52, P < 0.001; OR = 1.39, 95% CI = 1.24–1.57, P < 0.001; HR = 1.14, 95% CI = 1.05–1.24, P = 0.002, respectively). In contrast, among the living alone older adults, loneliness was only significantly associated with higher prevalence of frailty (OR = 1.42, 95% CI = 1.07–1.90, P = 0.017). Living arrangement significantly modified the associations of loneliness with prevalent cognitive impairment and 3-year mortality (P values for interaction = 0.005 and 0.026, respectively).

Conclusions

Living arrangement modifies the associations of loneliness with adverse health outcomes in community-dwelling older adults, and those who lived with others but felt lonely had worse cognitive and physical functions as well as higher mortality. Special attention should be paid to this population and more social services should be developed to reduce adverse health outcomes, in order to improve their quality of life and promote successful aging.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02742-5.

Sleep Duration and Frailty Risk among Older Adults: Evidence from a Retrospective, Population-Based Cohort Study

OBJECTIVES

Frailty and sleep duration complaints are both prevalent and often coexist among older adults. The purpose of this study was to examine the prospective association between sleep duration and frailty risk in a nationally representative cohort study.

DESIGN

Prospective cohort study, ten-year follow-up.

SETTING

Community-based setting in 23 provinces of China.

PARTICIPANTS

A total of 7623 older adults age 65 and over without frailty at baseline were included in the analysis.

MEASUREMENTS

The participants were divided into three groups according to self-reported sleep duration: short (≤6 hours per day), middle (>6 but <10 hours per day) and long (≥10 hours per day). Frailty was measured according to the accumulation of health deficits by the construction of a frailty index of 38 items with 0.25 as the cutoff. A Cox proportional hazard model, a competing risk model and a generalized estimating equation (GEE) model with multiple adjustments were performed to evaluate the association between sleep duration and frailty risk.

RESULTS

During a median follow-up period of 4.4 years (IQR 2.9-9.0), 2531 (33.2%) individuals developed frailty. Compared with participants with middle sleep duration, the risk of frailty was increased among participants with long sleep duration (HR 1.26, 95% CI 1.14-1.38) in the fully adjusted Cox proportional hazard model. However, short sleep duration was insignificantly associated with frailty risk. The competing risk model and the GEE model yielded similar results.

CONCLUSION

Long sleep duration is significantly associated with frailty incidence among older adults even after adjustment for confounding factors. This study provides reinforcing longitudinal evidence for the need to design sleep quality improvement interventions in health care programs to prevent frailty among older adults.

Green Space and Health in Mainland China: A Systematic Review

Non-communicable diseases (NCDs) have become a major cause of premature mortality and disabilities in China due to factors concomitant with rapid economic growth and urbanisation over three decades. Promoting green space might be a valuable strategy to help improve population health in China, as well as a range of co-benefits (e.g., increasing resilience to climate change). No systematic review has so far determined the degree of association between green space and health outcomes in China. This review was conducted to address this gap. Five electronic databases were searched using search terms on green space, health, and China. The review of 83 publications that met eligibility criteria reports associations indicative of various health benefits from more green space, including mental health, general health, healthier weight status and anthropometry, and more favorable cardiometabolic and cerebrovascular outcomes. There was insufficient evidence to draw firm conclusions on mortality, birth outcomes, and cognitive function, and findings on respiratory and infectious outcomes were inconsistent and limited. Future work needs to examine the health benefits of particular types and qualities of green spaces, as well as to take advantage of (quasi-)experimental designs to test greening interventions within the context of China's rapid urbanization and economic growth.

Relationship between Green and Blue Spaces with Mental and Physical Health: A Systematic Review of Longitudinal Observational Studies

There is growing interest in the ways natural environments influence the development and progression of long-term health conditions. Vegetation and water bodies, also known as green and blue spaces, have the potential to affect health and behaviour through the provision of aesthetic spaces for relaxation, socialisation and physical activity. While research has previously assessed how green and blue spaces affect mental and physical wellbeing, little is known about the relationship between these exposures and health outcomes over time. This systematic review summarised the published evidence from longitudinal observational studies on the relationship between exposure to green and blue space with mental and physical health in adults. Included health outcomes were common mental health conditions, severe mental health conditions and noncommunicable diseases (NCDs). An online bibliographic search of six databases was completed in July 2020. After title, abstract and full-text screening, 44 eligible studies were included in the analysis. Depression, diabetes and obesity were the health conditions most frequently studied in longitudinal relationships. The majority of exposures included indicators of green space availability and urban green space accessibility. Few studies addressed the relationship between blue space and health. The narrative synthesis pointed towards mixed evidence of a protective relationship between exposure to green space and health. There was high heterogeneity in exposure measures and adjustment for confounding between studies. Future policy and research should seek a standardised approach towards measuring green and blue space exposures and employ theoretical grounds for confounder adjustment.

New assessment for residential greenness and the association with cortical thickness in cognitively healthy adults

BACKGROUND

Recent evidence suggests that neurological health could be improved with the intervention of local green space. A few studies adopted cortical thickness, as an effective biomarker for neurodegenerative disorder, to investigate the association with residential greenness. However, they relied on limited data sources, definitions or applications to assess residential greenness. Our cross-sectional study assessed individual residential greenness using an alternative measure, which provides a more realistic definition of local impact and application based on the type of area, and investigated the association with cortical thickness.

METHODS

The study population included 2542 subjects who participated in the medical check-up program at the Health Promotion Center of the Samsung Medical Center in Seoul, Korea, from 2008 to 2014. The cortical thickness was calculated by each of the four and global lobes from brain MRI. For greenness, we used the enhanced vegetation index (EVI) that detects canopy structural variation by adjusting background noise based on satellite imagery data. To assess individual exposure to residential greenness, we computed the maximum annual EVI before the date of a medical check-up and averaged it within 750 m from subjects' homes to represent an average walking distance. Finally, we assessed the association with cortical thickness by urban and non-urban populations using multiple linear regression adjusting for individual characteristics.

RESULTS

The average global cortical thickness and EVI were 3.05 mm (standard deviation = 0.1 mm) and 0.31 (0.1), respectively. An interquartile range increase in EVI was associated with 11 μm (95% confidence interval = 3-20) and 9 μm (1-16) increases in cortical thickness of the parietal and occipital regions among the urban population. We did not find associations in non-urban subjects.

CONCLUSIONS

Our findings confirm the association between residential greenness and neurological health using alternative exposure assessments, indicating that high exposure to residential greenness can prevent neurological disorders.

Frailty in China: From Research to Practice

Although geriatric research in general has increased in recent years, there is no effective treatment for frailty. Among older adults, those with frailty have an increased risk of falls, disability, and death. The population of older adults has increased rapidly in China, and resulting in an increased demand for medical care services for older adults, including those with frailty. However, much of the research on frailty has been conducted in Europe and the United States, and European and American standards for frailty are not always applicable to Chinese individuals. Clinicians and researchers in China have shown increasing interest in frailty in recent years. Here, we reviewed the current state of frailty research in China.

Loneliness as a risk factor for frailty transition among older Chinese people

Background

Previous literature has reported that loneliness is a strong predictor of frailty risk. However, less is known about the role of loneliness in frailty transition types. This study aimed to examine whether and how loneliness are related to frailty transition among older Chinese people.

Methods

Our study used participants (aged ≥60 years) from 2008/2009, 2011/2012 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Loneliness was assessed by a single question asking how often the respondent feels lonely. The FRAIL Scale was created to measure physical frailty for our study, and frailty was also assessed by a broader definition of the frailty index. Frailty transition as an outcome variable has been designed as two types according to the measurement of frailty.

Results

Greater loneliness at baseline reduced the possibility of remaining in a robust or prefrail physical frailty state after 3 years (OR = 0.78, 95%CI: 0.68–0.91, p < 0.01). Greater loneliness was associated with an increased risk of worsening physical frailty over time: compared with those who had never felt lonely, the odds ratios for people who often felt lonely were 1.19 (95%CI: 1.01–1.41, p < 0.05) after 3 years and 1.34 (95%CI: 1.08–1.66, p < 0.01) after 6 years. The association between loneliness and change in the frailty index differed in the survey periods: loneliness at baseline was found to increase the possibility of participants remaining in frailty (seldom loneliness: OR = 1.78, 95%CI: 1.25–2.55, p < 0.01; often loneliness: OR = 1.74, 95%CI: 1.21–2.50, p < 0.01) after 6 years, but no significance was shown in the 3-year follow up. Additionally, loneliness at baselines was significantly associated with frailty transition at follow up among the male participants. However, a similar association was not observed among the female participants.

Conclusion

Older people with a high level of loneliness tend to be frail in the future, and greater loneliness is related to an increased risk of worsening frailty and remaining frail. Male elderly with a high level of loneliness were more likely to have a worse frailty transition than female elderly in China.

Residential Greenness Alters Serum 25(OH)D Concentrations: A Longitudinal Cohort of Chinese Older Adults

Objectives

Vitamin D deficiency is prevalent among older adults. We aimed to study whether residential greenness could alter serum 25(OH)D concentrations as a possible mechanism of residential greenness's positive health effects.

Design

A longitudinal cohort study.

Setting and Participants

We included older adults aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) with follow-up between 2012 and 2014.

Methods

We measured residential greenness by calculating annual average Normalized Difference Vegetation Index (NDVI) in a 500 m radius by using satellite images around each participant's residential address. Serum 25-hydroxyvitamin D (25(OH)D) concentration was dichotomized into 2 categories: nondeficiency (≥50 nmol/L) and deficiency (<50 nmol/L). We used the generalized estimating equation to examine the relationship between annual average NDVI and serum 25(OH)D.

Results

We included 1336 participants in our analysis. The annual average NDVI was 0.49, and mean serum 25(OH)D was 43 nmol/L at baseline. Each 0.1-unit increase in annual average NDVI was associated with a 13% higher odds of vitamin D nondeficiency [95% confidence interval (CI): 1.01, 1.26]. The association was stronger among men [odds ratio (OR): 1.17, 95% CI: 1.02, 1.35] than women (OR: 1.08, 95% CI: 0.91, 1.29) and also stronger among those who were free of activities of daily living (ADL) disability at baseline (OR: 1.12, 95% CI: 1.00, 1.25). During the follow-up period, the participants who lived in greener areas were more likely to have an improved, rather than stable or deteriorated, vitamin D status (OR: 1.94, 95% CI: 1.51, 2.51).

Conclusions and Implications

Our study suggests that higher levels of residential greenness are associated with higher serum 25(OH)D concentrations, which has implications for prevention of vitamin D deficiency among older adults.