Cognitive Function in Dementia-Free Subjects and Survival in Old Age: The PROSPER Study

Bidirectional associations of intellectual and social activities with cognitive function among middle-aged and elderly adults in China

BACKGROUND

Previous studies evaluating the association between leisure activities and cognitive function produced conflicting results. Different types of leisure activities may have different effects on cognition, and very few studies have explored their bidirectional associations. Our study aimed to explore whether intellectual and social activities had bidirectional associations with cognitive function among the middle-aged and elderly adults in China.

METHODS

Data was derived from the China Health and Retirement Longitudinal Study. The data in this study were based on 11,549 participants aged 45 or older whose intellectual and social activities and cognitive function were assessed at baseline. Cross-lagged panel model was used to examine the temporal relationship of intellectual and social activities with cognitive function.

RESULTS

Totally, 5624 participants completed the third follow-up in 2018. The results showed that the better the cognitive function they had at baseline, the more intellectual activities they were engage in (β = 0.044, P < 0.001) and vice versa (β = 0.042, P = 0.001). Additionally, better cognitive function at baseline was significantly associated with more engagement in social activities (β = 0.028, P = 0.030); in contrast, higher engagement in social activities at baseline was not related to better cognitive function (β = -0.008, P = 0.523).

LIMITATIONS

Engagement in social and intellectual activities was assessed via questionnaire.

CONCLUSIONS

Our findings indicated that there was a bidirectional relationship between intellectual activities and cognitive function. However, participation in social activities did not slow down the decline in cognitive function. Participating in intellectual activities, compared to social activities, is especially beneficial for cognitive function.

Cessie S, Marijt KA, Jukema JW, Mooijaart SP, van Buchem MA, van Hall T, Gussekloo J, Trompet S. Association of cognitive function with increased risk of cancer death and all-cause mortality: Longitudinal analysis, systematic review, and meta-analysis of prospective observational studies

Background

Disturbed cognitive function is associated with several causes of mortality; however, the association between cognitive function and the risk of cancer death has not been extensively investigated yet. We aimed to evaluate the association of cognitive function with the risk of cancer death and all-cause mortality in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) and Leiden 85-plus Study. Additionally, a systematic review and meta-analysis of longitudinal studies were conducted to evaluate the association of cognitive function and risk of cancer death.

Methods

Risk of cancer death and all-cause mortality were reported using hazard ratios (HRs) with 95% confidence interval (CI) in tertiles of cognitive function of PROSPER and Leiden85-Plus Study. Additionally, PubMed, Embase, Web of Science, Cochrane, PsycINFO, Academic Search Premier, CINHAL, and Emcare were searched up to November 1^st, 2020 to perform a systematic review and meta-analysis. The relative risks (RRs) with 95%CI of cancer death per each standard deviation lower performance in cognitive measurements were calculated.

Results

Participants of PROSPER had 1.65-fold (95%CI 1.11–2.47) greater risk of cancer death (P for trend = 0.016) and 1.85-fold (95%CI 1.46–2.34) higher risk of all-cause mortality (P for trend<0.001), in multivariable models. Results of the Leiden-85 Plus Study showed that subjects with MMSE score below 24 had a lower chance of cancer death (HR 0.79, 95%CI 0.36–1.70, P for trend = 0.820) but had 2.18-fold (95%CI 1.57–3.02) higher risk of all-cause mortality compared to the reference group (P for trend<0.001). Besides, the results of systematic review and meta-analysis showed that per each standard deviation lower performance in cognitive function, individuals were at a 10% higher chance of cancer death (RR 1.10, 95%CI 1.00–1.20, P-value = 0.044).

Conclusions

Lower cognitive function performance is associated with a marginally increased risk of cancer death, in line with a significantly greater risk of all-cause mortality.

Lowered cognitive function and the risk of the first events of cardiovascular diseases: findings from a cohort study in Lithuania

Background

The purpose of this prospective cohort study was to examine whether the level of cognitive function at the baseline expressed as a cognitive function composite score and score of specific domains predict the risk of first cardiovascular disease (CVD) events in middle-aged and older populations.

Methods

Seven thousand eighty-seven participants, men and women aged 45–72 years, were assessed in the baseline survey of the Health Alcohol Psychosocial Factors in Eastern Europe (HAPIEE) study in 2006–2008 in the city of Kaunas, Lithuania. During 10 years of follow-up, the risk of first non-fatal events of CVD and death from CVD (excluding those participants with a documented history of CVD and/or ischemic heart disease (IHD) diagnosed at the baseline survey) was evaluated. Cox proportional hazards regression models were applied to examine how cognitive function predicts the first events of CVD.

Results

During the follow-up, there were 156 deaths from CVD (49 women and 107 men) and 464 first non-fatal CVD events (195 women and 269 men) registered. The total number of first CVD events was 620 (11.5%). After adjustment for sociodemographic factors, biological and lifestyle risk factors and illnesses, a decrease per 1 standard deviation in different cognitive function scores significantly increased the risk of a first event of CVD (immediate verbal recall score - by 17% in men and 32% in women; delayed verbal recall score – by 17% in men and 24% in women; and a composite score of cognitive function – by 15% in men and 29% in women). Kaplan-Meier survival curves for the probability of a first cardiovascular event according to the categories of a composite score of cognitive function, revealed that a lowered cognitive function predicts a higher probability of the events compared to normal cognitive function (p < 0.05).

Conclusions

The findings of this follow-up study suggest that men and women with lower cognitive functions have an increased risk for a first event of CVD compared to participants with a higher level of cognitive functions.