Gymnastik- och idrottshögskolan, GIH

BACKGROUND AND OBJECTIVES: Individuals aged 70 and older frequently experience an increased risk of deficits in both physical and cognitive functions. However, the natural progression and interrelationship of these deficits, as well as their neurologic correlates, remain unclear. We aimed to classify the data-driven physical-cognitive phenotypes and then investigate their associations with neuroimaging markers.

METHODS: This cross-sectional study included 70-year-old participants from the Gothenburg H70 Birth Cohort (2014-2016). Based on physical performance (grip strength, balance, walking speed, and chair stand) and cognitive measures (episodic memory, perceptual speed, executive function, verbal fluency, and visuospatial abilities), we applied latent class analysis to identify physical-cognitive phenotypes. Based on the brain MRI measurements, 3 groups of neuroimaging markers were involved-neurodegeneration, cerebral small vessel disease (cSVD), and microstructural white matter (WM) integrity. We performed multinomial logistic regressions to examine the differences between the physical-cognitive phenotypes.

RESULTS: In total, 1,140 participants (female: 53.3%) without dementia and disability were included in the study, with 721 (female: 52.2%) undergoing MRI scans. Three physical-cognitive phenotypes were identified: an "optimal" group characterized by high performance in both physical and cognitive functions, an "intermediate" group showing a slight reduction in both domains, and a "physical deficit" group marked by a significant reduction in physical performance. Compared with the optimal group, the other 2 groups were more likely to present with vascular risk factors. The physical deficit group had higher odds of experiencing depression compared with the intermediate group (adjusted odds ratio [aOR] 2.9, 95% CI 1.4-5.9). Compared with the optimal group, the odds of presenting all 3 severe neuroimaging markers were higher in both the intermediate (aOR 3.4, 95% CI 1.5-7.9) and physical deficit (aOR 10.3, 95% CI 2.4-45.0) groups.

DISCUSSION: This study highlights the variability in physical and cognitive performance among older adults and suggests that neuroimaging markers of neurodegeneration, cSVD, and microstructural WM integrity may account for these variations. Our findings indicate the potential for developing group-based strategies to prevent and manage age-related functional decline. Further research with larger sample sizes is needed to deepen our understanding of physical-cognitive decline patterns.

BACKGROUND: Sarcopenia and cognitive impairment are two leading causes of disabilities.

OBJECTIVE: The objective was to examine the prevalence of sarcopenia and investigate the association between sarcopenia diagnostic components (muscle strength, muscle mass, and physical performance) and cognitive impairment in memory clinic patients.

METHODS: 368 patients were included (age 59.0±7.25 years, women: 58.7%), displaying three clinical phenotypes of cognitive impairments, i.e., subjective cognitive impairment (SCI, 57%), mild cognitive impairment (MCI, 26%), and Alzheimer's disease (AD, 17%). Sarcopenia was defined according to diagnostic algorithm recommended by the European Working Group on Sarcopenia in Older People. Components of sarcopenia were grip strength, bioelectrical impedance analysis, and gait speed. They were further aggregated into a score (0-3 points) by counting the numbers of limited components. Multi-nominal logistic regression was applied.

RESULTS: Probable sarcopenia (i.e., reduced grip strength) was observed in 9.6% of the patients, and 3.5% were diagnosed with sarcopenia. Patients with faster gait speed showed less likelihood of MCI (odds ratio [OR]: 0.24, 95% confidence interval [CI]: 0.06-0.90) and AD (OR: 0.12, 95% CI: 0.03-0.60). One or more limited sarcopenia components was associated with worse cognitive function. After adjusting for potential confounders, the association remained significant only for AD (OR 4.29, 95% CI 1.45-11.92).

CONCLUSION: The results indicate a connection between the sarcopenia components and cognitive impairments. Limitations in the sarcopenia measures, especially slow walking speed, were related to poorer cognitive outcomes. More investigationsare required to further verify the causal relationship between sarcopenia and cognitive outcomes.

This study aimed to quantify the relationships between the American Heart Association (AHA) Cardiovascular Health (CVH) metrics, namely AHA Life's Simple 7, and cognitive outcomes. We searched PubMed and Embase (January 1, 2010-August 24, 2022) and finally included 14 longitudinal studies (311654 participants with 8006 incident dementia cases). Random-effects meta-analysis and one-stage linear mixed-effects models were performed. Increased CVH score seemed to associate with decreased risk of incident dementia in a linear manner, but this relationship varied by the measurement age of CVH metrics. That is, midlife CVH tended to have a linear association with late-life dementia risk, whereas a J-shaped association was observed between the late-life CVH score and dementia. In addition, late-life dementia risk was reduced significantly if individuals maintained an ideal level of AHA's CVH guidelines of physical activity, fasting plasma glucose, total cholesterol, and smoking. However, our meta-analysis did not show a significant association between CVH score and global cognitive decline rate. Following AHA's CVH guidelines and maintaining CVH at an optimal level would substantially reduce the late-life dementia risk. More research is required to explore the link between a favorable CVH score and cognitive trajectories among cognitively asymptomatic older populations.

The concept of reserve has been developed to account for the discontinuity between the extent of brain damage at its clinical manifestation in the form of cognitive decline or dementia. In this chapter, we discuss contributors to cognitive reserve from various stages of the life-course, including childhood, early adulthood, middle age, and late life. Evidence from observational studies as well as intervention trials is presented and assessed. We conclude by arguing that reserve formation in dementia risk is a life-course process whereby baseline cognitive abilities are subjected to modulation by subsequent experiences at diverse stages over the entire life-course. Variations among individuals in their ability to withstand age-related brain changes are ultimately dependent on their life-time accumulation of mental, physical, and lifestyle inputs into cognitive reserve.