Social determinants of intrinsic capacity: A systematic review of observational studies.

BACKGROUND: The World Health Organization defined healthy ageing as the maintenance of functional ability with ageing. Intrinsic capacity is a measurement of healthy ageing, and can be shaped by social determinants. However, an overall understanding of how multiple social determinants contribute to intrinsic capacity remains unclear. We aim to summarize observational studies investigating the relationships between social determinants and intrinsic capacity among community-dwelling adults. METHODS: A systematic search was conducted through Medline, Embase, PsycInfo, Web of Science, and CINAHL until August 14, 2023. RESULTS: After reviewing 813 articles, we included 21 studies from nine countries in Asia, Europe, and America. Seventeen studies used a cross-sectional design and the others were longitudinal studies. Social determinants related to intrinsic capacity can be classified into five domains, containing socioeconomic status (16, 76.2% of studies), lifestyles (14, 66.7%), psychosocial factors (9, 42.9%), material circumstances (4, 19.0%), and healthcare systems (1, 4.8%). Strong evidence supported that better intrinsic capacity was associated with higher education, higher wealth, more physical activities, no smoking, more social engagement, and being married or partnered. The relationships of intrinsic capacity with dietary patterns and alcohol drinking were contradictory across studies. Research on the associations of working status, housing environments, and healthcare accessibility with intrinsic capacity was insufficient to draw conclusions. CONCLUSION: These findings highlight roles of socioeconomic status, lifestyles, and psychosocial factors in improving intrinsic capacity thus promoting healthy ageing. Future research is needed to investigate causal relationships between social determinants and intrinsic capacity, especially material circumstances and healthcare systems.

The association between vision impairment and cognitive outcomes in older adults: a systematic review and meta-analysis.

OBJECTIVES: To provide a quantitative synthesis of studies on the relationship between vision impairment (VI) and cognitive outcomes in older adults. METHOD: A systematic search was undertaken of relevant databases for original articles published before April 2020. Random effect models were used to obtain pooled estimates of the associations between VI and cognitive outcomes (cognitive impairment and dementia) with subgroup analyses of VI measures, cross-sectional associations of VI with cognitive impairment, and longitudinal associations of baseline VI with incident cognitive impairment and dementia. Potential sources of heterogeneity were explored by meta-regression. Publication bias was evaluated with Egger's test. RESULTS: Sixteen studies including 76,373 participants were included in this meta-analysis, with five cross-sectional studies and eleven longitudinal studies. There was a significantly increased risk of cognitive outcomes with VI identified by subjective measures (odds ratio (OR)=1.63; 95% confidence interval (CI): 1.26-1.99) and objective measures (OR = 1.59; 95% CI: 1.40-1.78). The odds of baseline cognitive impairment were 137% higher in older adults with VI compared with those without VI (OR = 2.37, 95% CI: 1.84-3.03) at baseline. Compared with older adults without VI at baseline, those with baseline VI had a higher relative risk (RR) of incident cognitive impairment (RR = 1.41; 95% CI: 1.31-1.51) and dementia (RR = 1.44, 95% CI: 1.19-1.75). CONCLUSIONS: VI was associated with increased risks of cognitive impairment and dementia across cross-sectional and longitudinal studies. Additional research and randomized clinical trials are warranted to examine the implications of treatment for VI, such as wearing glasses and cataract surgery, to avoid cognitive impairment and dementia.

Multimorbidity measures differentially predicted mortality among older Chinese adults.

OBJECTIVES: This study aimed to examine and compare the associations between different multimorbidity measures and mortality among older Chinese adults. STUDY DESIGN AND SETTING: Using the Chinese Longitudinal Healthy Longevity Survey 2002-2018, data on fourteen chronic conditions from 13,144 participants aged ≥65 years were collected. Multimorbidity measures included condition counts, multimorbidity patterns (examined by exploratory factor analysis), and multimorbidity trajectories (examined by a group-based trajectory model). Mortality risk associated with different multimorbidity measures was each analyzed using Cox regression. C-statistic, the Integrated Discrimination Improvement (IDI), and the Net Reclassification Index (NRI) were used to compare the performance of different multimorbidity measures. RESULTS: Participants with multimorbidity, regardless of measurements, had a higher risk of death compared with people without multimorbidity. Compared with the mortality prediction model using age and sex, C-statistics showed added discrimination (over 0.77, all P < .05) for models with multimorbidity measures. Multimorbidity trajectory showed integrated discrimination and net reclassification improvement for mortality prediction compared to condition count (IDI = 0.042, NRI = 0.033) and multimorbidity pattern (IDI = 0.041, NRI = 0.069). CONCLUSION: Adding multimorbidity measures significantly improved the performance of a mortality prediction model using age and sex as predictors. Trajectory-based measures of multimorbidity performed better than count- and pattern-based measures for mortality prediction.

Patterns of cardiometabolic multimorbidity and the risk of depressive symptoms in a longitudinal cohort of middle-aged and older Chinese.

BACKGROUND: Cardiometabolic diseases (CMDs) are associated with depression. However, it is unclear whether coexisting CMDs may increase the risk of depression. We examined associations between cardiometabolic multimorbidity and depressive symptoms among middle-aged and older Chinese. METHODS: Participants aged ≥45 years were enrolled from the China Health and Retirement Longitudinal Study 2011-2018 (N = 18,002). Cardiometabolic multimorbidity was defined as the coexistence of ≥2 CMDs, including stroke, heart disease, diabetes, hypertension, and dyslipidemia. Depressive symptoms were assessed by the Center for Epidemiological Studies Depression Scale. We used generalized estimating equation models to examine associations between cardiometabolic multimorbidity and depressive symptoms, including the dose effect of disease count and prevalent disease combinations, as well as individual and additive effects of specific CMDs. RESULTS: The prevalence of cardiometabolic multimorbidity was 24.5%. A higher number of CMDs had an additive dose effect on depressive symptoms that persisted consistently in specific CMDs. Stroke only, heart disease only, and diabetes only were each associated with a higher risk of depressive symptoms compared with no CMDs. CMD combinations involving stroke, heart disease, or diabetes were each associated with an increased risk of depressive symptoms compared with the absence of stroke, heart disease, or diabetes. LIMITATION: Self-reported chronic conditions. CONCLUSION: Stroke, heart disease, and diabetes showed individual and additive effects on CMD combinations, whereas hypertension and dyslipidemia only showed associations with depressive symptoms in combinations with other CMDs. These results suggest person-centered healthcare of mental health prevention and treatment for middle-aged and older adults with individual or multiple CMDs.

Vision impairment, vision correction, and cognitive decline among middle-aged and older Chinese: results from the China health and retirement longitudinal study.

OBJECTIVES: To investigate the associations between vision impairment (VI), vision correction (VC), and cognitive function. METHOD: We included 20,677 participants aged ≥45 years from the China Health and Retirement Longitudinal Study (2011-2015). Participants were grouped into no VI, distance VI (DVI) only, near VI (NVI) only, or both distance and near VI (DNVI), and VI(+)/VC(-), VI(+)/VC(+), VI(-)/VC(-), or VI(-)/VC(+) further at baseline. Cognitive function at baseline and subsequently every two years was applied as a dependent variable in a generalized estimating equation model. RESULTS: DVI only, NVI only, and DNVI had significantly worse cognitive function over time than no VI (all p < .05). DNVI had significantly worse cognitive function over time than DVI only and NVI only (all p < .001). VI(+)/VC(+), VI(-)/VC(-), and VI(-)/VC(+) had significantly better cognitive function over time than VI(+)/VC(-) (all p < .05). VI(-)/VC(+) had significantly better cognitive function over time than VI(+)/VC(+) and VI(-)/VC(-) (all p < .05). CONCLUSION: Cognitive function was worse in middle-aged and older Chinese with VI, especially in those with DNVI. VC was associated with better cognitive function over time regardless of the status of vision.

Associations between Multimorbidity and Physical Performance in Older Chinese Adults.

Background: Evidence on the association between physical performance and multimorbidity is scarce in Asia. This study aimed to identify multimorbidity patterns and their association with physical performance among older Chinese adults. Methods: Individuals aged ≥60 years from the China Health and Retirement Longitudinal Study 2011-2015 (N = 10,112) were included. Physical performance was measured by maximum grip strength (kg) and average gait speed (m/s) categorized as fast (>0.8 m/s), median (>0.6-0.8 m/s), and slow (≤0.6 m/s). Multimorbidity patterns were explored using exploratory factor analysis. Generalized estimating equation was conducted. Results: Four multimorbidity patterns were identified: cardio-metabolic, respiratory, mental-sensory, and visceral-arthritic. An increased number of chronic conditions was associated with decreased normalized grip strength (NGS). Additionally, the highest quartile of factor scores for cardio-metabolic (ß = -0.06; 95% Confidence interval (CI) = -0.07, -0.05), respiratory (ß = -0.03; 95% CI = -0.05, -0.02), mental-sensory (ß = -0.04; 95% CI = -0.05, -0.03), and visceral-arthritic (ß = -0.04; 95% CI = -0.05, -0.02) patterns were associated with lower NGS compared with the lowest quartile. Participants with ≥4 chronic conditions were 2.06 times more likely to have a slow gait speed. Furthermore, the odds ratios for the highest quartile of factor scores of four patterns with slow gait speed compared with the lowest quartile ranged from 1.26-2.01. Conclusion: Multimorbidity was related to worse physical performance, and multimorbidity patterns were differentially associated with physical performance. A shift of focus from single conditions to the requirements of a complex multimorbid population was needed for research, clinical guidelines, and health-care services. Grip strength and gait speed could be targeted to routinely measure clinical performance among older adults with multimorbidity, especially mental-sensory disorders, in clinical settings.

Associations Between Somatic Multimorbidity Patterns and Depression in a Longitudinal Cohort of Middle-Aged and Older Chinese.

OBJECTIVES: Depressive symptoms are commonly seen among patients with multiple chronic somatic conditions, or somatic multimorbidity (SMM); however, little is known about the relationships between depressive symptoms and different SMM combinations. Our study aimed to delineate the patterns of SMM and their longitudinal associations with depressive symptoms among a nationally representative sample of middle-aged and older Chinese adults. DESIGN: We employed a longitudinal design. SETTING AND PARTICIPANTS: Older adults (N = 10,084) aged ≥45 years from the China Health and Retirement Longitudinal Study 2011-2015 participated (mean age = 57.7 years at baseline; 53.3% men). METHODS: Sixteen chronic somatic conditions were ascertained at baseline via questionnaires. Depression was assessed with the Center for Epidemiological Studies Depression Scale at baseline and during follow-up. Patterns of SMM were identified via exploratory factor analyses. Generalized estimating equations were used to evaluate the longitudinal associations between patterns of SMM and the presence of depressive symptoms at follow-up. RESULTS: Compared with participants with no somatic condition, those with 1, 2, and 3 or more somatic conditions had a 21%, 66%, and 111% greater risk, respectively, for the presence of depressive symptoms. Increased factor scores for 4 patterns identified, cardio-metabolic pattern [adjusted odds ratio (AOR) 1.12, 95% confidence interval (CI) 1.06, 1.20], respiratory pattern (AOR 1.25, 95% CI 1.17, 1.33), arthritic-digestive-visual pattern (AOR 1.29, 95% CI 1.22, 1.37), and hepatic-renal-skeletal pattern (AOR 1.09, 95% CI 1.02, 1.16), were all associated with a higher risk of having depressive symptoms. CONCLUSIONS AND IMPLICATIONS: All SMM patterns were independently associated with depression among middle-aged and older Chinese adults, with greater odds for people with comorbid arthritic-digestive-visual conditions and respiratory conditions. Clinical practitioners should treat the middle-aged and older population under a multiple-condition framework combining SMM and mental disorders.

Prevalence and Patterns of Multimorbidity in a Nationally Representative Sample of Older Chinese: Results From the China Health and Retirement Longitudinal Study.

BACKGROUND: Multimorbidity has become a prominent problem worldwide; however, few population-based studies have been conducted among older Chinese with multimorbidity. This study aimed to examine the prevalence of multimorbidity and explore its common patterns among a nationally representative sample of older Chinese. METHODS: This study used data from the China Health and Retirement Longitudinal Study and included 19,841 participants aged at least 50 years. The prevalence of individual chronic diseases and multimorbidity during 2011-2015 were evaluated among the entire cohort and according to residential regions and gender. The relationships between participants' demographic characteristics and multimorbidity were examined using logistic regression model. Patterns of multimorbidity were explored using hierarchical cluster analysis and association rule mining. RESULTS: Multimorbidity occurred in 42.4% of the participants. The prevalence of multimorbidity was higher among women (odds ratio [OR] = 1.31, 95% confidence interval [CI]: 1.13-1.51) and urban residents (OR = 1.14, 95% CI: 1.02-1.27) than their respective counterparts after accounting for potential confounders of age, education, smoking, and alcohol consumption. Hierarchical cluster analysis revealed four common multimorbidity patterns: the vascular-metabolic cluster, the stomach-arthritis cluster, the cognitive-emotional cluster, and the hepatorenal cluster. Regional differences were found in the distributions of stroke and memory-related disease. Most combinations of conditions and urban-rural difference in multimorbidity patterns from hierarchical cluster analysis were also observed in association rule mining. CONCLUSION: The prevalence and patterns of multimorbidity vary by gender and residential regions among older Chinese. Women and urban residents are more vulnerable to multimorbidity. Future studies are needed to understand the mechanisms underlying the identified multimorbidity patterns and their policy and interventional implications.