| Objectives: Worldwide populations are aging rapidly due to increased life expectancy and reduced mortality in late-life.Understanding potential risk factors and protected healthy lifestyles among the oldest-old is of great importance for healthy aging and healthy longevity in the rapidly expanding group of the oldest-old.Based on the Chinese Longitudinal Healthy Longevity Surveys(CLHLS),this study mainly investigated the role of health behavior factors in reducing the risk of all-cause mortality in the oldest-old.This study aimed to: 1)examine whether and to what extent the harmful effect of risk factors on all-cause mortality can be counteracted by healthy lifestyles(smoking,alcohol intake,exercise,diet and BMI)in oldest-old;2)investigate the association between sleep duration and all-cause mortality,and to assess effect modification of cognitive impairment in this association among oldest-old;3)investigate whether and to what extent the effect of cognitive impairment on all-cause mortality can be attenuated by leisure activities(LAs)in older people.Methods: The study was designed as a prospective cohort study.The population of this study were older people over 80 years old from the CLHLS,which was conducted at baseline in 2005 and followed up in 2008,2011 and 2014.Data of baseline and follow-up were collected through self-administered questionnaires and physical examinations.Health behavioral factors included in this study consisted of lifestyle,sleep and leisure activities.Lifestyle scores were weighted by smoking,drinking,diet,physical activity and BMI.Sleep duration was reported by the oldest-old;Leisure activities include nine self-reported activities,such as social activities,mental activities and physical activities.The level of cognitive function was assessed by Mini-Mental State Examination(MMSE)scale,and MMSE≤24 points was defined as cognitive impairment.This study also included social demographic characteristics,health behavioral factors,physical indicators,disease status and other information.During the follow-up,survival status,date of death,whether the study was completed or lost to follow-up were recorded.The death status of the study subjects was determined by the close relatives of the elderly or the village doctors.STATA 15.0 and R 3.6.1 were used for statistical analysis.Hazard ratios(HRs)and 95% confidence intervals(CIs)were calculated using a multi-model adjusted Cox proportional hazards models to examine the associations of lifestyle,sleep duration,cognitive function,and leisure activity with all-cause mortality.Multiple sensitivity analysis were performed to verify the robustness of the results.Results: 1.We found that rural residence,not in marriage,lower economic situation,physical disability,impaired cognitive function,comorbidity was independently associated with higher mortality.The HR of the highest quartile of risk factor scores compared with the lowest quartile was 2.38(95% CI: 2.27-2.50),and the HR of the highest quartile of lifestyle scores compared with the lowest quartile was 0.74(95% CI: 0.70-0.77).Participants with the highest risk factors and the lowest healthy lifestyle had a nearly three-fold increased risk of mortality(HR = 2.97,95% CI: 2.76-3.20).Adherence to a healthy lifestyle can offset a 23 percent risk of mortality from risk factors in oldest-old.2.Oldest-old who slept 7-9 hours had the lowest risk of mortality.After adjusting for confounders of cognitive function,physical function,and multimorbidity,<7 hours of sleep duration were not significantly associated with the risk of mortality,whereas >9 hours of sleep increased the risk of mortality by 13%(HR = 1.13,95% CI: 1.08-1.18).Sleep duration was associated with a J-shaped risk of all-cause mortality.In stratified analysis by cognitive function,physical disability and multimorbidity,the association between long sleep and morality was present only among people with MMSE≤24,but did not differ much when stratified by physical disability and multimorbidity.There was a statistically significant interaction between long sleep and cognitive impairment on mortality(P for interaction = 0.002).3.After adjusting for confounders,active leisure activities could reduce 39% risk of all-cause mortality(HR= 0.61,95% CI: 0.57-0.66).Active participation in excess leisure activities significantly increased the survival rate.Individuals with cognitive impairment who did not actively participate in leisure activities had a 99% increased risk of mortality(HR=1.99,95% CI: 1.82-2.17).Among the individuals with normal cognition,active leisure activities can reduce the risk of mortality by 39%(HR=0.61,95% CI: 0.54-0.69),while among the individuals with cognitive impairment,active leisure activities can significantly reduce 41% the risk of mortality(HR= 0.59,95% CI: 0.54-0.66),and leisure activities and cognitive functions have a significant interactive effect on the risk of mortality(P = 0.023).Conclusion: Adherence to healthy lifestyle counteracts the negative effect of risk factors on all-cause mortality in oldest-old by more than 20%.Long sleep duration is associated with higher mortality in very old adults independently of health conditions.Cognitive impairment may play a modulating role in this association,which suggest that beneficial sleep duration can reduce death risk associated with cognitive impairment.Leisure activities might compensate for the greater total mortality associated with cognitive impairment in older individuals,and the beneficial effect of Leisure activities on mortality varied by cognitive function.These findings underscore the need to promote healthy living as a preventive strategy,and to improve the management of healthy lifestyles,as a result of yielding important practical implications for very old adults to reach longevity. |
PDF Full Text Request