Predictors of depression among middle-aged and older men and women in Europe: A machine learning approach

Background: The high prevalence of depression in a growing aging population represents a critical public health issue. It is unclear how social, health, cognitive, and functional variables rank as risk/protective factors for depression among older adults and whether there are conspicuous differences among men and women. Methods: We used random forest analysis (RFA), a machine learning method, to compare 56 risk/protective factors for depression in a large representative sample of European older adults (N = 67,603; ages 45-105y; 56.1% women; 18 countries) from the Survey of Health, Ageing and Retirement in Europe (SHARE Wave 6). Depressive symptoms were assessed using the EURO-D questionnaire: Scores ≥ 4 indicated depression. Predictors included a broad array of sociodemographic, relational, health, lifestyle, and cognitive variables. Findings: Self-rated social isolation and self-rated poor health were the strongest risk factors, accounting for 22.0% (in men) and 22.3% (in women) of variability in depression. Odds ratios (OR) per +1SD in social isolation were 1.99x, 95% CI [1.90,2.08] in men; 1.93x, 95% CI [1.85,2.02] in women. OR for self-rated poor health were 1.93x, 95% CI [1.81,2.05] in men; 1.98x, 95% CI [1.87,2.10] in women. Difficulties in mobility (in both sexes), difficulties in instrumental activities of daily living (in men), and higher self-rated family burden (in women) accounted for an additional but small percentage of variance in depression risk (2.2% in men, 1.5% in women). Interpretation: Among 56 predictors, self-perceived social isolation and self-rated poor health were the most salient risk factors for depression in middle-aged and older men and women. Difficulties in instrumental activities of daily living (in men) and increased family burden (in women) appear to differentially influence depression risk across sexes

Age-Related Trajectories of General Fluid Cognition and Functional Decline in the Health and Retirement Study: A Bivariate Latent Growth Analysis

There have been few studies on associations between age-related declines in fluid cognition and functional ability in population-representative samples of middle-aged and older adults. We used a two-stage process (longitudinal factor analysis followed by structural growth modeling) to estimate bivariate trajectories of age-related changes in general fluid cognition (numeracy, category fluency, executive functioning, and recall memory) and functional limitation (difficulties in daily activities, instrumental activities, and mobility). Data came from the Health and Retirement Study (Waves 2010–2016; N = 14,489; ages 50–85 years). Cognitive ability declined on average by −0.05 SD between ages 50–70 years, then −0.28 SD from 70–85 years. Functional limitation increased on average by +0.22 SD between ages 50–70 years, then +0.68 SD from 70–85 years. Significant individual variation in cognitive and functional changes was observed across age windows. Importantly, cognitive decline in middle age (pre-age 70 years) was strongly correlated with increasing functional limitation (r = −.49, p &lt; .001). After middle age, cognition declined independently of change in functional limitation. To our knowledge, this is the first study to estimate age-related changes in fluid cognitive measures introduced in the HRS between 2010–2016.</jats:p

Age-Related Trajectories of General Fluid Cognition and Functional Decline in the Health and Retirement Study: A Bivariate Latent Growth Analysis

There have been few studies on associations between age-related declines in fluid cognition and functional ability in population-representative samples of middle-aged and older adults. We used a two-stage process (longitudinal factor analysis followed by structural growth modeling) to estimate bivariate trajectories of age-related changes in general fluid cognition (numeracy, category fluency, executive functioning, and recall memory) and functional limitation (difficulties in daily activities, instrumental activities, and mobility). Data came from the Health and Retirement Study (Waves 2010&ndash;2016; N = 14,489; ages 50&ndash;85 years). Cognitive ability declined on average by &minus;0.05 SD between ages 50&ndash;70 years, then &minus;0.28 SD from 70&ndash;85 years. Functional limitation increased on average by +0.22 SD between ages 50&ndash;70 years, then +0.68 SD from 70&ndash;85 years. Significant individual variation in cognitive and functional changes was observed across age windows. Importantly, cognitive decline in middle age (pre-age 70 years) was strongly correlated with increasing functional limitation (r = &minus;.49, p &lt; .001). After middle age, cognition declined independently of change in functional limitation. To our knowledge, this is the first study to estimate age-related changes in fluid cognitive measures introduced in the HRS between 2010&ndash;2016

Association between physical performance and cognitive function in older adults across multiple studies: A pooled analysis study

Abstract Background and Objectives While several studies have examined the association between cognitive and physical function, the consistency of these associations across functional contexts is unclear. The consistency of association between cognitive and physical function performance was examined at baseline across 17 clinical studies with diverse and heterogeneous conditions such as overweight/obese, sedentary, at risk for a mobility disability, osteoarthritis, low vitamin D, or had signs of cognitive impairment. Research Design and Methods Data are from 1,388 adults 50 years and older who completed a cognitive and physical function assessment as part of a research study at the Wake Forest Alzheimer’s Disease Research Center or the Wake Forest Older Americans Independence Center. Linear regression models were used to relate cognitive measures [Mini Mental Status Exam (MMSE), Montreal Cognitive Assessment (MoCA), and the Digit Symbol Substitution Task (DSST)], and physical measures [the Short Physical Performance Battery (SPPB) and hand grip strength] for the whole sample and treat each study as a fixed effect. All models controlled for age, sex, race, and body mass index (BMI). Results Overall, there was a significant association between higher scores on the MMSE (per standard deviation) and better physical function performance (SPPB score b= 0.24, p &amp;lt;0.001) and its components (gait speed, chair rise, and standing balance; p’s &amp;lt;0.05). Higher scores on the MoCA produced similar results (SPPB score b= 0.31, p= &amp;lt;0.001) and higher scores on the DSST were also significantly associated with a better SPPB score (b= 0.75, p &amp;lt;0.001). The relationship between DSST and physical function performance demonstrated a stronger magnitude of association compared to the MMSE or MoCA. Discussion and Implications Older adults with heterogenous health conditions showed a consistent pattern between better cognitive function and better physical function performance with the strongest association among DSST scores. </jats:sec

Predictors of cognitive and physical decline: Results from the Health Aging and Body Composition Study

BackgroundRisk factors for cognitive decline and physical decline have been studied independently, however older adults might experience decline in both areas i.e., dual decline. Risk factors associated with dual decline are largely unknown and have significant implications on health outcomes. The aim of this study is to explore risk factors associated with dual decline.MethodsUsing data from the Health, Aging and Body Composition (Health ABC) study, a longitudinal prospective cohort study, we examined trajectories of decline based on repeated measures of the Modified Mini-Mental State Exam (3MSE) and the Short Physical Performance Battery (SPPB) across 6 years (n=1,552). We calculated four mutually exclusive trajectories of decline and explored predictors of decline: cognitive decline (n = 306) = lowest quartile of slope on the 3MSE or 1.5 SD below mean at baseline, physical decline (n = 231) = lowest quartile of slope on the SPPB or 1.5 SD below mean at baseline, dual decline (n = 110) = lowest quartile in both measures or 1.5 SD below mean in both measures at baseline. Individuals who did not meet criteria for one of the decline groups were classified as the reference group. (n= 905).ResultsMultinomial logistic regression tested the association of 17 baseline risk factors with decline. Odds of dual decline where significantly higher for individuals at baseline with depressive symptoms (CES-D &amp;gt;16) (Odds Ratio (OR)=2.49, 95% Confidence Interval (CI): 1.05-6.29), ApoE-ε4 carrier (OR= 2.09, 95% CI: 1.06-1.95), or if individuals had lost 5+lbs in past year (OR=1.79, 95% CI: 1.13-2.84). Odds were significantly lower for individuals with a higher score on the Digit Symbol Substitution Test per standard deviation (OR per SD: 0.47, 95% CI 0.36-0.62) and faster 400-meter gait (OR per SD= 0.49, 95% CI: 0.37-0.64).ConclusionAmong predictors, depressive symptoms at baseline significantly increased the odds of developing dual decline but was not associated with decline in the exclusively cognitive or physical decline groups. APOE-ε4 status increased the odds for cognitive decline and dual decline but not physical decline. More research on dual decline is needed because this group represents a high risk, vulnerable subset of older adults.</jats:sec

Can Nutrition or Inflammation Moderate the Age-Cognition Association Among Older Adults?

Objectives: Previous research has shown that nutrition can influence cognitive abilities in older adults. We examined whether nutritional factors or inflammatory biomarkers moderate the age-cognition association. Method: Analyses included 1,308 participants (age ≥60) from the National Health and Nutrition Examination Survey III. Macronutrients (% of calories from fat, protein, and carbohydrates), micronutrients/amino acids (blood serum values: Vitamins B12, C, D, E, folate, iron, homocysteine, and β-carotene), and inflammatory biomarkers (serum C-reactive protein, plasma fibrinogen, and serum ferritin) were examined as moderators with cognition. Cognition was measured by six tasks: immediate and delayed story recall, immediate and delayed word memory, digit subtraction, and questions about place/orientation. Results: Higher values of serum folate were significantly associated with better cognitive scores. Specifically, the interaction between age-cognition and folate indicated the associations of higher age and lower global cognition and lower immediate story recall were weaker in those with higher folate values (p’s \u3c .05). A significant interaction between age and plasma fibrinogen indicated that the association between age and worse digit subtraction was stronger with values \u3e3.1 g/L. Discussion: Folate and fibrinogen were significant moderators between age and cognition. Further research into the relationship between nutrition, inflammation, and cognitive aging is needed

Examining the intersection of cognitive and physical function measures: Results from the brain networks and mobility (B-NET) study

Background and objectivesAlthough evidence exists that measures of mobility and cognition are correlated, it is not known to what extent they overlap, especially across various domains. This study aimed to investigate the intersection of 18 different objective cognitive and physical function measures from a sample of unimpaired adults aged 70 years and older.Research design and methodsCanonical correlation analysis was utilized to explore the joint cross-sectional relationship between 13 cognitive and 6 physical function measures in the baseline visit of the Brain Networks and Mobility Function (B-NET) Study (n = 192).ResultsMean age of participants was 76.4 years. Two synthetic functions were identified. Function 1 explained 26.3% of the shared variability between the cognition and physical function variables, whereas Function 2 explained 19.5%. Function 1 termed “cognitive and physical speed” related the expanded Short Physical Performance Battery (eSPPB), 400-m walk speed, and Dual Task gait speed measures of physical function to semantic fluency animals scores, Digit Symbol Coding (DSC), and Trail Making Test B. Function 2 termed “complex motor tasks and cognitive tasks” related the Force Plate Postural Sway Foam Task and Dual Task to the following cognitive variables: MoCA Adjusted Score, Verbal Fluency L words, Craft story immediate and delayed recall, and Trail Making Test B.Discussion and implicationsWe identified groups of cognitive and physical functional abilities that were linked in cross-sectional analyses, which may suggest shared underlying neural network pathway(s) related to speed (Function 1) or complexity (Function 2).Translational significanceWhether such neural processes decline before measurable functional losses or may be important targets for future interventions that aim to prevent disability also remains to be determined.</jats:sec