Visual trajectories and risk of physical and cognitive impairment among older Chinese adults

Predictors and consequences of visual trajectories in Chinese older population: A growth mixture model

Background

Given the relatively high prevalence of vision impairment and the heterogeneity of visual changes among the elderly population, we aimed to identify the visual trajectories and to examine the predictors and consequences associated with each trajectory class.

Methods

We analysed data from 2235 participants involved in the 5th, 6th, 7th, and 8th waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), where vision impairment was evaluated using an adapted Landolt-C chart during each wave. We employed a growth mixture model (GMM) to identify distinct visual trajectories and logistic regression analysis to examine the predictors associated with each trajectory class. Furthermore, we investigated the effect of visual trajectories on distal consequences, including cognitive function, activities of daily living (ADL), instrumental activities of daily living (IADL), depression, anxiety, and fall risk. Within the CLHLS study, cognitive function was assessed using the Chinese version of the Mini-Mental State Examination (CMMSE), ADL via the Katz index, and IADL through a modified version of Lawton's scale. Lastly, depression was assessed using the 10-item version of the Centre for Epidemiologic Studies (CES-D-10), while anxiety was measured using the Generalized Anxiety Disorder scale (GAD-7). Fall risk was determined by asking the question: 'Have you experienced any falls within the past year?'

Results

We identified two distinct visual trajectories in our analysis. Most older adults (n = 1830, 81.9%) initially had a good vision level that diminished ('high-baseline decline' group). Conversely, the remaining participants (n = 405, 18.1%) initially had a lower vision level that improved over time ('low-baseline improvement' group). The 'high-baseline decline' group was more likely to include older adults with relatively higher body mass index (BMI) (odds ratio (OR) = 1.086; 95% confidence interval (CI) = 1.046, 1.127), individuals with higher formal educational qualifications (OR = 1.411; 95% CI = 1.068, 1.864), those current engaging in exercise (OR = 1.376; 95% CI = 1.046, 1.811), and individuals reporting more frequent consumption of fruit (OR = 1.357; 95% CI = 1.053, 1.749). Conversely, the 'low-baseline improvement' group had a higher likelihood of including older individuals (OR = 0.947; 95% CI = 0.934, 0.961), residents of nursing homes (OR = 0.340; 95% CI = 0.116, 0.993) and those self-reporting cataracts (OR = 0.268; 95% CI = 0.183, 0.391) and glaucoma (OR = 0.157; 95% CI = 0.079, 0.315). Furthermore, the 'high-baseline decline' group showed a positive impact on distal consequences, adjusting for sex, birthplace, residence, main occupation, education, economic status, and marital status. This impact included cognitive function (correlation coefficient (β) = 2.092; 95% CI = 1.272, 2.912), ADL (β  = -0.362; 95% CI = -0.615, -0.108), IADL (β  = -1.712; 95% CI = -2.304, -1.121), and reported lower levels of depression (β  = 0.649; 95% CI = 0.013, 1.285). We observed no significant influence on fall risk and anxiety within the identified visual trajectories in the adjusted model.

Conclusions

Vision in older adults with ocular disease could potentially be improved. Having formal education, maintaining an appropriate BMI, engaging in exercise, and consuming fruit more frequently appear to be beneficial for the visual health of the elderly. Considering the negative impact of visual impairment experience on distal cognition, self-care ability, and depression symptoms, stakeholder should prioritise long-term monitoring and management of vision impairment among older adults.

The relationship between visual function and physical performance in the Study of Muscle, Mobility and Aging (SOMMA)

PURPOSE

The relationship of types of visual function to different aspects of physical function, especially strength and coordination, has been understudied, but delineation of these relationships could suggest potentially modifiable targets prior to the onset of disability.

METHODS

Cross-sectional analysis of visual function (self-reported eyesight and eye disease, visual acuity, contrast sensitivity) and physical function tests in 877 older adults (mean age 76.36±5.01 years, 59.2% women, and 13.3% Black race). Separate linear regression models were constructed for short physical performance battery (SPPB), expanded SPPB (eSPPB), their components (gait speed, chair stand, balance, narrow walk), stair climb, four-square step, leg extension peak power and strength, and grip strength.

RESULTS

In adjusted models, worse acuity, worse contrast sensitivity, and self-reported poor vision were significantly associated with worse performance on the eSPPB and four-square step test. Worse contrast sensitivity, but not acuity, was significantly associated with shorter balance times, slower chair stand pace, longer stair climb time, and worse SPPB score. Associations of worse acuity and contrast sensitivity with weaker leg extension power, leg strength, and grip strength were attenuated by covariate adjustment. Self-reported macular degeneration, but not cataract or glaucoma, was associated with worse performance on SPPB, eSPPB, balance, stair climb, and four-square step tests in adjusted models. Worse contrast sensitivity and macular degeneration remained associated with worse SPPB and balance after controlling for visual acuity and self-reported eyesight.

CONCLUSIONS

Poor contrast sensitivity was more strongly associated with worse physical performance than acuity, especially for complex tasks that dynamically challenge coordination and balance. Future studies should examine if older adults with contrast sensitivity impairment would benefit from targeted intervention to decrease their risk of disability.

Association of biomass fuel use with the risk of vision impairment among Chinese older adults: a cohort study

Cooking with biomass fuels has been reported to have adverse effects on health. This study aims to explore the association between cooking with biomass fuels and vision impairment among Chinese older adults aged 65 years and above. This cohort study drew on data from the 2011/2012 wave and the 2014 follow-up wave of the Chinese Longitudinal Healthy Longevity Survey. Participants' visual function was examined through a vision screening test. Exposure to indoor biomass fuels was self-reported. Cox proportional hazards models were applied to explore the relationship between biomass fuel use and vision impairment. Additionally, we compared the risk of vision impairment between participants who switched cooking fuel types and those who did not. Subgroup and interaction analyses were conducted to explore the potential effect modifiers. A total of 4711 participants were included in this study. During the follow-up, 1053 (22.35%) participants developed vision impairment. Cooking with biomass fuels increased the risk of vision impairment by 40% (hazard ratio [HR]: 1.40, 95% confidence interval [CI]: 1.21-1.61). Participants who switched from clean fuels to biomass fuels had a greater risk of vision impairment than persistent clean fuel users (HR: 1.44, 95% CI: 1.03-2.00). Greater effect estimates were found in participants who lived in eastern and central China and urban residents. Cooking with biomass fuels resulted in a greater risk of vision impairment among Chinese older adults. This risk also existed in those who changed their cooking fuels from clean fuels to biomass fuels. Further studies with an objective assessment of biomass fuel combustion are required to confirm our findings.

Intrinsic Capacity to Predict Future Adverse Health Outcomes in Older Adults: A Scoping Review

OBJECTIVE

Intrinsic capacity is recognized as an important determinant of healthy aging and well-being of older adults; however, relatively little is known about the intrinsic capacity of older adults to predict adverse health outcomes. The study aimed to examine which adverse health outcomes of older adults can be predicted by intrinsic capacity.

METHODS

The study was conducted using the scoping review methodological framework of Arksey and O'Malley. A systematic literature search of nine electronic databases (i.e., Pubmed, Embase, Cochrane library, Web of science, CINAHL, China National Knowledge Infrastructure, VIP, Wanfang, and the Chinese Biological Medical Literature Database) were performed from the database's inception to 1 March 2022.

RESULTS

Fifteen longitudinal studies were included. A series of adverse health outcomes were assessed, including physical function (n = 12), frailty (n = 3), falls (n = 3), mortality (n = 6), quality of life (n = 2) and other adverse health outcomes (n = 4).

CONCLUSIONS

Intrinsic capacity could predict some adverse health outcomes of different follow-up times for older adults; however, due to the small number of studies and sample size, more high-quality studies are necessary to explore the longitudinal relationships between intrinsic capacity and adverse health outcomes in the future.

Trends in the prevalence of vision impairment among the oldest-old Chinese population from 1998 to 2018

Background

Vision impairment has become a prominent public health issue worldwide. However, little is known about vision impairment prevalence trends among the oldest-old adults in China. This study aimed to examine 20-year trends in the prevalence of vision impairment among the oldest-old Chinese adults and explore the contributions of sociodemographic variables, health behaviours, and chronic conditions to the trends.

Methods

This retrospective longitudinal study used data from the Chinese Longitudinal Healthy Longevity Survey during 1998-2018. A total of 45 849 participants aged ≥80 years at study entry were included. Vision impairment was assessed by an adapted Landolt-C chart at each wave. We examined unadjusted and adjusted nonlinear trends using generalized estimating equation models incorporating a natural cubic spline. We conducted linear regression models to estimate absolute annual prevalence changes and determine the contributions of sociodemographic variables, health behaviours, and chronic conditions to the trends.

Results

The fully adjusted prevalence doubled from 5.5% (95% confidence interval (CI) = 5.1%-6.0%) in 1998 to 10.7% (95% CI = 9.9%-11.5%) in 2011 and slightly increased to 11.1% (95% CI = 10.3%-12.0%) in 2018 among the oldest-old Chinese population. Glaucoma, cataracts, cognitive impairment, hearing impairment, and urban residence were significant contributors to changes in vision impairment prevalence during 1998-2018. Differences in vision impairment prevalence associated with glaucoma and cataracts narrowed since 2005. Disparities in the trends among cognitively impaired and unimpaired older adults remained unchanged over time. Similar results were observed in older people with and without hearing impairment.

Conclusions

Vision impairment prevalence among the oldest-old Chinese population increased from 1998 to 2011 and remained stable from 2011 to 2018. Future work is needed to improve the prevention and management of chronic diseases associated with vision impairment to reduce its prevalence.

Relationships of leisure activities with physical and cognitive functions among Chinese older adults: A prospective community-based cohort study

OBJECTIVES

Based on a prospective design, this study aimed to investigate the relationships of leisure activities with physical and cognitive functions among Chinese older adults.

METHODS

The respondents aged 65 years or more were selected from the 2014-2018 of the Chinese Longitudinal Healthy Longevity Survey. Physical function measurement indicators were reflected by activities of daily living (ADL), instrumental activities of daily living (IADL), and physical performance (PP), while cognitive function was assessed by Mini-Mental State Examination. Fine-Gray competing risk regression models were used to analyze the data.

RESULTS

Using the figures for 2014 as a baseline for the study, we included 6047, 6216, 5951, and 5916 respondents in the ADL, IADL, PP, and cognitive function analyses, respectively. The prospective results showed that keeping domestic animals or pets was related to a lower risk of ADL disability of respondents after adjustment (SHR: 0.619, 95% CI: 0.486, 0.788). Similarly, taking part in social activities (SHR: 0.781, 95%CI: 0.658, 0.929) and reading books or newspapers (SHR: 0.793, 95% CI: 0.656, 0.958) were associated with a lower risk of IADL disability. Playing cards or mahjong was correlated with a lower risk of cognitive impairment (SHR: 0.669, 95% CI: 0.507, 0.882), while keeping domestic animals or pets was related to a higher risk of cognitive impairment (SHR: 1.279, 95% CI: 1.047, 1.562).

CONCLUSION

Participation in leisure activities moderately may decrease the risk of a decline in physical and cognitive functions among Chinese older adults.

Development and Validation of a Multimorbidity Index Predicting Mortality Among Older Chinese Adults

Objective

This study aimed to develop and validate a multimorbidity index using self-reported chronic conditions for predicting 5-year mortality risk.

Methods

We analyzed data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and included 11,853 community-dwelling older adults aged 65–84 years. Restrictive association rule mining (ARM) was used to identify disease combinations associated with mortality based on 13 chronic conditions. Data were randomly split into the training (N = 8,298) and validation (N = 3,555) sets. Two multimorbidity indices with individual diseases only (MI) and disease combinations (MIDC) were developed using hazard ratios (HRs) for 5-year morality in the training set. We compared the predictive performance in the validation set between the models using condition count, MI, and MIDC by the concordance (C) statistic, the Integrated Discrimination Improvement (IDI), and the Net Reclassification Index (NRI).

Results

A total of 13 disease combinations were identified. Compared with condition count (C-statistic: 0.710), MIDC (C-statistic: 0.713) showed significantly better discriminative ability (C-statistic: p = 0.016; IDI: 0.005, p < 0.001; NRI: 0.038, p = 0.478). Compared with MI (C-statistic: 0.711), the C-statistic of the model using MIDC was significantly higher (p = 0.031), while the IDI was more than 0 but not statistically significant (IDI: 0.003, p = 0.090).

Conclusion

Although current multimorbidity status is commonly defined by individual chronic conditions, this study found that the multimorbidity index incorporating disease combinations showed supreme performance in predicting mortality among community-dwelling older adults. These findings suggest a need to consider significant disease combinations when measuring multimorbidity in medical research and clinical practice.

Associations Between Intrinsic Capacity and Adverse Events Among Nursing Home Residents: The INCUR Study

OBJECTIVES

The predictive ability of the novel intrinsic capacity (IC) construct has been scarcely investigated in the nursing home setting. The objective of this study was to investigate the associations of IC and its individual domains with mortality, hospitalization, pneumonia onset, and functional status decline in a population of nursing home residents (NHRs).

DESIGN

We undertook an analysis using data from the INCUR study, a prospective observational study. Data were collected at baseline, at 6 and 12 months by trained staff.

SETTING AND PARTICIPANTS

A total of 371 NHRs (mean age 85.91 ± 7.34) dwelling in Southern France.

METHODS

A baseline IC composite score was constructed from scores in the Short Physical Performance Battery, Abbreviated Mental Test, 10-item Geriatric Depression Scale, The Short Form of the Mini-Nutritional Assessment, and self-reported hearing and vision impairments. Adverse outcomes were registered by medical records checking. Functional status evolution was evaluated through changes in the Katz Index. Cox regression was used for associations between IC and its domains and adverse outcomes. Linear mixed models were used in the case of functional status evolution.

RESULTS

Our analysis revealed associations between a composite score of IC and death [hazard ratio 0.33; 95% confidence interval (CI) 0.15-0.73] and functional status evolution (β = 0.14; 95% CI 0.018-0.29) in our population. Although greater values in IC vitality/nutrition domain were associated with survival (HR 0.84; 95% CI 0.70-0.99), IC cognitive domain was associated with decreased odds of hospitalization (HR 0.91; 95% CI 0.84-0.99) and lower declines in functional status (β = 0.04; 95% CI 0.01-0.07), whereas the IC locomotion domain was inversely associated with pneumonia incidence (HR 0.84; 95% CI 0.72-0.98).

CONCLUSIONS AND IMPLICATIONS

Our results contribute to preliminary evidence linking greater IC levels and lower risk of late-life adverse outcomes.