Objective To examine reciprocal relations of loneliness and cognitive function in older adults. Methods Data were analyzed from 8382 men and women, age 65 and older, participating in the US Health and Retirement Study from 1998 to 2010. Participants underwent biennial assessments of loneliness and depression (classified as no, low or high depression) determined by the Center for Epidemiologic Studies Depression scale (8-item version), cognition (a derived memory score based on a word list memory task and proxy-rated memory and global cognitive function), health status and social and demographic characteristics from 1998 to 2010. We used repeated measures analysis to examine the reciprocal relations of loneliness and cognitive function in separate models controlling sequentially and cumulatively for socio-demographic factors, social network, health conditions and depression. Results Loneliness at baseline predicted accelerated cognitive decline over 12 years independent of baseline socio-demographic factors, social network, health conditions and depression (β =−0.2, p = 0.002). After adjustment for depression interacting with time, both low and high depression categories were related to faster cognitive decline and the estimated effect of loneliness became marginally significant. Reciprocally, poorer cognition at baseline was associated with greater odds of loneliness over time in adjusted analyses (OR 1.3, 95% CI (1.1–1.5) p = 0.005), but not when controlling for baseline depression. Furthermore, cognition did not predict change in loneliness over time. Conclusion Examining longitudinal data across a broad range of cognitive abilities, loneliness and depressive symptoms appear to be related risk factors for worsening cognition but low cognitive function does not lead to worsening loneliness over time.

Background: Little evidence is available on the effects of incident diabetes or diabetes duration on cognitive aging. Methods: We evaluated the effects of prevalent and incident diabetes on deteriorations in cognitive function, based on participants (n = 8,671) aged 65+ in the Health and Retirement Study in 2000. Inverse probability weighting was used to account for selective attrition and time-varying confounding of incident diabetes. Results: Prevalent diabetes predicted higher odds of dementia [odds ratio 1.27; 95% confidence interval (CI) 1.03-1.58] and worse memory (-0.06 in z-score units; 95% CI -0.10 to -0.02), but incident diabetes or diabetes duration up to 8 years of follow-up was not predictive. Conclusion: Prevalent diabetes predicted lower cognition but not recent onset diabetes.

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Subjective assessment may be incomparable across countries due to differences in reporting styles. Based on two nationally representative surveys from the US and China, this study used data from three anchoring vignettes to estimate to what extent the US and Chinese older adults aged 50 and above differed in their reporting styles of subjective cognitive impairment. Cross country differences of subjective cognitive impairment were then estimated, both before and after adjusting for reporting heterogeneity. Directly assessed word recall test scores were analyzed to evaluate whether findings based on subjective cognitive impairment was consistent with objective performance. The results revealed a discrepancy between self-reported subjective cognitive impairment and directly assessed memory function among older adults: while Chinese respondents reported lower severity levels of subjective cognitive impairment, the US respondents demonstrated better performance in immediate word recall tests. By accounting for differences in reporting styles using anchoring vignettes data, Chinese older adults showed higher levels of subjective cognitive impairment than the US older adults, which was consistent with results from direct assessment of memory function. Non-negligible differences are present in reporting styles of subjective cognitive impairment. Cross country comparison needs to take into account such reporting heterogeneity.

BACKGROUND Individual-level modifiers can delay onset of limitations in basic activities of daily living (ADLs) among cognitively impaired individuals. We assessed whether these modifiers also delayed onset of limitations in instrumental ADLs (IADLs) among individuals at elevated dementia risk. OBJECTIVES To determine whether modifiable individual-level factors delay incident IADL limitations among adults stratified by dementia risk. METHODS Health and Retirement Study participants aged 65+ without activity limitations in 1998 or 2000 (N=5,219) were interviewed biennially through 2010. Dementia probability, categorized in quartiles, was used to predict incident IADL limitations with Poisson regression. We estimated relative (risk ratio) and absolute (number of limitations) effects from models including dementia, individual-level modifiers (physical inactivity, smoking, no alcohol consumption, and depression) and interaction terms between dementia and individual-level modifiers. RESULTS Dementia probability quartile predicted incident IADL limitations (relative risk for highest versus lowest quartile=0.44; 95% CI: 0.28–0.70). Most modifiers did not significantly increase risk of IADL limitations among the cognitively impaired. Physical inactivity (RR=1.60; 95% CI: 1.16, 2.19) increased the risk of IADL limitations among the cognitively impaired. The interaction between physical inactivity and low dementia probability was statistically significant (p=0.009) indicating that physical inactivity had significantly larger effects on incident IADLs among cognitively normal than among those with high dementia probability. CONCLUSION Physical activity may protect against IADL limitations while smoking, alcohol consumption and depression do not afford substantial protection among the cognitively impaired. Results highlight the need for extra support for IADLs among individuals with cognitive losses.