Objective Handgrip strength, an indicator of overall muscle strength, has been found to be associated with slower rate of cognitive decline and decreased risk for cognitive impairment and dementia. However, evaluating the replicability of associations between aging-related changes in physical and cognitive functioning is challenging due to differences in study designs and analytical models. A multiple-study coordinated analysis approach was used to generate new longitudinal results based on comparable construct-level measurements and identical statistical models and to facilitate replication and research synthesis. Methods We performed coordinated analysis on 9 cohort studies affiliated with the Integrative Analysis of Longitudinal Studies of Aging and Dementia (IALSA) research network. Bivariate linear mixed models were used to examine associations among individual differences in baseline level, rate of change, and occasion-specific variation across grip strength and indicators of cognitive function, including mental status, processing speed, attention and working memory, perceptual reasoning, verbal ability, and learning and memory. Results were summarized using meta-analysis. Results After adjustment for covariates, we found an overall moderate association between change in grip strength and change in each cognitive domain for both males and females: Average correlation coefficient was 0.55 (95% CI = 0.44–0.56). We also found a high level of heterogeneity in this association across studies. Discussion Meta-analytic results from nine longitudinal studies showed consistently positive associations between linear rates of change in grip strength and changes in cognitive functioning. Future work will benefit from the examination of individual patterns of change to understand the heterogeneity in rates of aging and health-related changes across physical and cognitive biomarkers.

An association between level of cognitive function and grip strength is well established while evidence for longitudinal associations of change in the two functions are still unclear. We examined associations between cognition and grip strength in levels of performance and in longitudinal change in late life in a population-based sample, aged 80 years and older at baseline, followed until death. The sample consisted of 449 non-demented individuals drawn from the OCTO-twin study. A test battery assessing 6 cognitive domains and grip strength was administered at five occasions with measurements intervals of two years. We fitted time to death bivariate growth curve models, adjusted for age, education and sex which resulted in associations between grip strength and cognition in both levels of performance (across all cognitive domains) and rates of change (in four out of six domains). These results show that cognition and grip strength change conjointly in later life and that the association between cognition and grip strength is stronger prior to death than earlier in life.

Background Substantial research is dedicated to understanding the aging-related dynamics among individual differences in level, change, and variation across physical and cognitive abilities. Evaluating replicability and synthesizing these findings has been limited by differences in measurements and samples, and by study design and statistical analyses confounding between-person differences with within-person changes. In this article, we conducted a coordinated analysis and summary meta-analysis of new results on the aging-related dynamics linking pulmonary function and cognitive performance. Methods We performed coordinated analysis of bivariate growth models in data from 20,586 participants across eight longitudinal studies to examine individual differences in baseline level, rate of change, and occasion-specific variability in pulmonary and cognitive functioning. Results were summarized using meta-analysis. Results We found consistent but weak baseline and longitudinal associations in levels of pulmonary and cognitive functioning, but no associations in occasion-specific variability. Conclusions Results provide limited evidence for a consistent link between simultaneous changes in pulmonary and cognitive function in a normal aging population. Further research is required to understand patterns of onset of decline and differences in rates of change within and across physical and cognitive functioning domains, both within-individuals and across countries and birth cohorts. Coordinated analysis provides an efficient and rigorous approach for replicating and comparing results across independent longitudinal studies.

This is the first longitudinal study to report on significant associations in late life between GGT, cognitive performance and dementia. Further research is needed to examine the underlying mechanisms of GGT as a marker of age-related cognitive decline.

Abstract. In 1987, we administered a subjective memory questionnaire to 143 40-year-old men, and 30 years later 67 of them again responded to the same questionnaire at age 70. At the follow-up, we also instructed participants to answer the questionnaire in the same manner as they thought they did at age 40 and to perform a picture recognition and a public event test. We employed confirmatory factor analysis to model a latent subjective memory construct. A single-factor solution provided acceptable model fit to data (χ2(12) = 9.33, p = .68; χ2(12) = 10.48, p = .57) and a decent reliability at both ages for the subjective memory measurements (omega = .82 and .93, respectively). Our longitudinal invariance testing revealed only a partial weak invariance. We also fitted a latent change-score model to the data. As expected, participants on average rated their memory as poorer at age 70 than at 40. Those who reported better overall health and less anxiety reported less memory decline up to age 70. Notably, this was also the case for those who rated memory as worse at age 40. Higher stress and depression at age 70, however, were associated with worse subjective memory already at age 40. The correspondences between memory ratings and tests were low. The correlation between the subjective memory factors at age 40 and 70 was 0.58, while the correlation between the memory factor at age 70 and the retrospective subjective memory factor was 0.87. Our findings suggest that subjective memory is quite consistent, and that we are inclined to preserve the continuity of our own memory functioning over the adult lifespan.