Residential Proximity to Major Roadways and Prevalent Hypertension Among Older Women and Men: Results From the Chinese Longitudinal Healthy Longevity Survey

Association between garden work and risk of incident dementia in an older population in China: a national cohort study

OBJECTIVES

Evidence on the association between garden work and risk of incident dementia in the older Chinese population is limited. This study aimed to explore the association between the frequency of garden work and risk of incident dementia in an older population in China.

STUDY DESIGN

This was a national cohort study.

METHODS

This study analysed data from 8676 participants (median age: 86 years) from the Chinese Longitudinal Healthy Longevity Survey. Cox proportional hazard models were used to assess the association between the frequency of garden work and risk of incident dementia using hazard ratios (HRs) and 95% confidence intervals (CIs). Multiplicative and additive interaction effects were calculated between the frequency of garden work and age, sex or residence on incident dementia; subgroup analyses of the association were also conducted by age, sex and residence. In addition, sensitivity analyses were performed to assess the robustness of the results.

RESULTS

During 4.31 years (median) of follow-up, 633 participants developed dementia. Compared with participants who did not engage in garden work, the adjusted risk of incident dementia for those who regularly or almost daily engaged in garden work decreased by 28% (HR = 0.72, 95% CI: 0.57-0.93). An additive interaction effect between frequency of garden work and age on incident dementia was observed, with subgroup analyses demonstrating similar statistically significant associations among participants aged ≥85 years, women and city or town residents. Sensitivity analyses were consistent with the primary analysis in the present study.

CONCLUSIONS

Frequent engagement in garden work may be associated with a reduced risk of dementia and may be an effective measure to prevent incident dementia in the older population in China.

Association between residential proximity to major roadways and chronic multimorbidity among Chinese older adults: a nationwide cross-sectional study

BACKGROUND

Multiple negative health outcomes were linked to residential proximity to major roadways. Nevertheless, there is limited knowledge regarding the association between residential proximity to major roadways and chronic multimorbidity.

METHODS

We used data from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey, which included 12,214 individuals aged ≥ 60. We derived the residential proximity to major roadways from self-reported data, defining chronic multimorbidity as the presence of two or more concurrent chronic diseases. A binary logistic regression model was utilized to investigate the association between residential proximity to major roadways and chronic multimorbidity. The model accounted for some demographic features, socioeconomic conditions, social participation, and health conditions. Subsequently, we conducted subgroup analyses to examine potential interaction effects.

RESULTS

Residential proximity to major roadways was associated with chronic multimorbidity, even after adjusting for confounding factors. Compared with those living > 300 m from major roadways, the OR for those living 201-300 m, 101-200 m, 50-100 m, and < 50 m were increased. When subgroup analyses were conducted using a cutoff point of 200 m, the risk of chronic multimorbidity associated with residential proximity to major roadways was stronger in participants with education levels > 6 years (P = 0.017).

CONCLUSION

Our findings provide important implications for improving residential area siting, transportation policies, and environmental regulations to reduce the risk of chronic multimorbidity caused by traffic-related exposure.

Association of 3-year change in sleep duration with risk of all-cause mortality in Chinese older population: A national cohort study

BACKGROUND

Existing evidence on the association of dynamic change in sleep duration with risk of all-cause mortality in Chinese older population is limited. We aimed to explore the association of 3-year change in sleep duration with risk of all-cause mortality in a Chinese older population.

MATERIALS AND METHODS

A total of 5772 Chinese older participants (median age 82 years) were enrolled in the current study. Cox proportional-hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of 3-year change in sleep duration with risk of all-cause mortality. Subgroup analyses of the association between 3-year change in sleep duration and risk of all-cause mortality were conducted by age, sex and residence.

RESULTS

During a median of 4.08 years of follow-up, death developed in 1762 participants. Compared with -1 to <1 h/day change in sleep duration, the adjusted risk of all-cause mortality with < -3 h/day change in sleep duration may increase 26% (HR = 1.26, 95% CI: 1.05-1.52); the risk of all-cause mortality with 3-year change from short to long sleep duration, or long to short sleep duration versus stable normal sleep duration status was increased about 28% and 52%, respectively (HR = 1.28, 95% CI: 1.00-1.64 and HR = 1.52, 95% CI: 1.21-1.92). Subgroup analyses demonstrated that similar significant associations were observed among participants with 65 to <85 years, men and living in city and town.

CONCLUSIONS

Dynamic sleep duration change was significantly associated with risk of all-cause mortality. The current study suggests that sleep duration may be a non-invasive indicator for interventions aiming to reduction risk of all-cause mortality in Chinese older population.

Interaction of greenness and polygenic risk score of Alzheimer's disease on risk of cognitive impairment

Studies have shown contact with nature has positive psychological, neurological, and cognitive benefits. Whether the built environment can affect genetic predisposition of Alzheimer's disease (AD) should be explored. We aimed to examine whether greenness around the residential environment can modify the effect of genetic AD risk on cognitive function. We used a genetic sub-study of the Chinese Longitudinal Healthy Longevity Survey including 1199 older adults (mean age: 100.3 ± 3.4 years) aged 90 years old or older. We used Polygenic Risk Score (PRS) to quantify the genetic AD risk and two types of measurements based on Normalized Difference Vegetation Index (NDVI) to access the residential greenness (contemporaneous and annual average NDVI). Contemporaneous NDVI values were the NDVI value collected at the corresponding survey, and the annual average NDVI was the average value of NDVI during the year before the corresponding survey. We defined cognitive impairment as having a Mini-Mental State Examination score below 25. In the multivariable logistics regression models, contemporaneous NDVI and genetic AD risk were associated with cognitive impairment. Among those with low genetic AD risk, the risk of cognitive impairment was lower in those living around higher greenness (contemporaneous NDVI OR: 0.55, 95% CI: [0.34, 0.86]; P_interaction: 0.071; annual average NDVI OR: 0.49, 95% CI: [0.31, 0.79]; P_interaction: 0.040). We did not observe significant associations between greenness and cognitive impairment among those with high genetic AD risk. Prevention efforts using PRS warrant a higher granularity of environmental exposures and biological etiology data.

All-Cause Mortality Risk Associated With Solid Fuel Use Among Chinese Elderly People: A National Retrospective Longitudinal Study

Background: The adverse health effects of air pollutants are widely reported, and the elderly are susceptible to toxic environments. This study aimed to evaluate the association between use of solid fuels for cooking and mortality among the elderly. Methods: A total of 5,732 and 3,869 participants from the Chinese Longitudinal Healthy Longevity Survey were enrolled in two (2014 and 2018) and three surveys (2011, 2014, and 2018) of survey. Cooking fuel was divided into clean and solid fuel. Cox proportional hazards models were used to estimate the mortality hazard ratio (HR). Subgroup analyses were performed to assess the potential interaction effect. Results: Among the participants in the 2011-2018 survey, 53% reported using solid fuel. Such group was associated with a 9% increase in mortality risk relative to clean fuel users (HR = 1.09, 95% CI = 1.01-1.18). Among participants in the 2014-2018 survey, 339 reported a switch from solid to clean fuels and they were not at increased mortality risk relative to the 488 people that reported a stable use of clean fuels (HR = 1.14, 95% CI = 0.99-1.31) although the estimated HR was similar to the one for stable solid fuel users (HR = 1.19, 95%CI = 1.04-1.36 n = 509). Interaction and stratified analyses showed that solid fuel use had an impact on mortality in participants who were non-current smokers, had low dietary diversity scores, and were living in areas with high PM2.5 concentrations (>50 μg/m3) and city population below 8 million (P for interaction < 0.05). The association was robust in the three sensitivity analyses. Conclusion: The finding showed a clear association between solid fuel use and mortality among older Chinese, and an even stronger association between risk of mortality and solid fuel use among individuals exposed to high levels of PM2.5.