Associations between body composition and cognitive function in an elderly Korean population: A cohort-based cross-sectional study

Body Composition, Sarcopenic Obesity, and Cognitive Function in Older Adults: Findings From the National Health and Nutrition Examination Survey (NHANES) 1999-2002 and 2011-2014

OBJECTIVE

Sarcopenic-obesity (SO) is characterized by the concomitant presence of low muscle mass and high adiposity. This study explores the association of body composition and SO phenotypes with cognitive function in older adults.

METHODS

Cross-sectional data in older adults (≥60 years) from NHANES 1999-2002 and 2011-2014 were used. In the 1999-2002 cohort, phenotypes were derived from body mass index (BMI) and dual-X-ray-absorptiometry, and cognition was assessed the by Digit-Symbol-Substitution-Test (DSST). In the 2011-2014 cohort, phenotypes were derived from BMI, waist-circumference (WC), and hand-grip-strength (HGS). Cognition was assessed using four tests: DSST, Animal Fluency, the Consortium-to-Establish-a-Registry-for-Alzheimer's-Disease-Delayed-Recall, and Word Learning. Mediation analysis was conducted to evaluate the contribution of inflammation (C-reactive-protein, CRP) and insulin resistance (Homeostatic-Model-Assessment-for-Insulin-Resistance, HOMA-IR) to the association between body composition and cognitive outcomes.

RESULTS

The SO phenotype had the lowest DSST mean scores (p < 0.05) and was associated with a significant risk of cognitive impairment [Odds Ratio (OR) = 1.9; 95%CI 1.0-3.7, p = 0.027] in the 1999-2002 cohort. A higher ratio of fat mass and fat free mass (FM/FFM) also showed a greater risk of cognitive impairment (OR = 2.0; 95%CI 1.3-3.1, p = 0.004). In the 2011-2014 cohort, the high WC-Low HGS group showed significantly lower scores on all four cognitive tests (p < 0.05) and a higher risk of cognitive impairment. CRP and HOMA-IR were significant partial mediators of the association between FM/FFM and DSST in the 1999-2002 cohort.

CONCLUSIONS

The SO phenotype was associated with a higher risk of cognitive impairment in older adults. Insulin resistance and inflammation may represent key mechanisms linking SO to the development of cognitive impairment.

Association between physical activity, body composition, and cognitive performance among female office workers

Regular physical activity can potentially prevent cognitive decline. While most studies focused on the general decline of the elderly and child and adolescent population, aging is a gradual process and cognitive decline can commence in middle age. Other than the middle-aged working population, gender-specific nuances are another overlooked area regarding the relationship between physical activity and cognitive performance. Therefore, this study examines the associations and benefits of maintaining regular physical activity habits with cognitive function and body composition in middle-aged female office workers. The results show that middle-aged females exhibited age-related declines in working memory, while no significant age-related changes are observed in reaction time and executive function. However, the regular exercise group demonstrates the ability to maintain their cognitive performance across age, unlike the sedentary group, who experiences declines in reaction time and executive function with age. Our findings highlight the significant impact of age on specific cognitive functions in middle-aged females and the positive influence of regular exercise on cognitive performance. Furthermore, this study demonstrates the potential of "the Brain Gym" App for efficient cognitive function assessment. The findings underscore the importance of regular exercise for cognitive well-being in middle-aged females and provide valuable insights into the relationship between body composition and cognitive function.

Reduced body cell mass and functions in lower extremities are associated with mild cognitive impairment and Alzheimer's dementia

This study examined the alterations of segmental body composition in individuals with Alzheimer's pathology (AD), including mild cognitive impairment (MCI) and dementia. A multifrequency bioimpedance analysis (BIA) was used to provide segmental water and impedance variables from 365 cognitively normal (CN), 123 MCI due to AD, and 30 AD dementia participants. We compared the BIA variables between the three groups, examined their correlations with neuropsychological screening test scores, and illustrate their 95% confidence RXc graphs. AD dementia participants were older, more depressive, and had worse cognitive abilities than MCI due to AD and CN participants. Although the BIA variables showed weak partial correlations with the cognitive test scores, we found patterns of an increasing water content in lean mass, increasing extra to intracellular water ratio, and decreasing reactance and phase angle in the lower extremities with effect sizes ranging from 0.26 to 0.51 in the groups of MCI and dementia due to AD compared with CN individuals. The RXc graphs upheld the findings with a significant displacement downward and toward the right, dominantly in the lower extremities. Individuals with AD pathology exhibit a reduced body cell mass or cell strength, an abnormal cellular water distribution, and an overhydration status in lean mass, especially in the lower extremities.

Translational research into frailty from bench to bedside: Salivary biomarkers for inflammaging

Frailty is a complex physiological syndrome associated with adverse ageing and decreased physiological reserves. Frailty leads to cognitive and physical disability and is a significant cause of morbidity, mortality and economic costs. The underlying cause of frailty is multifaceted, including immunosenescence and inflammaging, changes in microbiota and metabolic dysfunction. Currently, salivary biomarkers are used as early predictors for some clinical diseases, contributing to the effective prevention and treatment of diseases, including frailty. Sample collection for salivary analysis is non-invasive and simple, which are paramount factors for testing in the vulnerable frail population. The aim of this review is to describe the current knowledge on the association between frailty and the inflammatory process and discuss methods to identify putative biomarkers in salivary fluids to predict this syndrome. This study describes the relationship between i.-inflammatory process and frailty; ii.-infectious, chronic, skeletal, metabolic and cognitive diseases with inflammation and frailty; iii.-inflammatory biomarkers and salivary fluids. There is a limited number of previous studies focusing on the analysis of inflammatory salivary biomarkers and frailty syndrome; hence, the study of salivary fluids as a source for biomarkers is an open area of research with the potential to address the increasing demands for frailty-associated biomarkers.

Obesity marker trajectories and cognitive impairment in older adults: a 10-year follow-up in Taichung community health study for elders

BACKGROUND

Obesity and cognitive impairment prevalence increases as age increases. Recent growing evidence finds links between obesity and cognitive impairment in older adults. However, the association between the two is controversial. This study aims to identify obesity marker trajectory patterns, and to assess whether these patterns are associated with cognitive impairment and cognitive decline during a 10-year follow-up period among community-dwelling older adults.

METHODS

A total of 626 older adults aged 65 and older were involved in the study, with at least two repeated measurements at baseline, one-year or 10-year follow-up. Cognitive function was measured through the Mini Mental State Examination. Obesity markers included body mass index, waist circumference, waist-to-hip (WHR), fat mass (FM), and abdominal fat (AF) measured by dual-energy X-ray absorptiometry. Multivariate logistic regression analyses were performed to estimate the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of cognitive impairment and cognitive decline for obesity marker trajectory patterns.

RESULTS

After a 10-year follow-up, 168 older adults with incident cognitive impairment and 156 with rapid cognitive decline were defined as the top 25th percentile of cognitive decline. Four distinct trajectory groups of obesity markers were identified. In multivariate logistic regression analyses, a low likelihood of cognitive impairment was observed in the consistently high-level group from FM trajectory (ORs = 0.41, 95% CI = 0.20-0.85); the high-level U-shaped group from WHR trajectory (0.43, 0.22-0.84); and the median-level flat inverse U-shaped, consistently high-level, and low-level flat U-shaped groups from AF trajectory (0.44, 0.26-0.77; 0.33, 0.18-0.61; 0.39, 0.18-0.82). In addition, a low likelihood of rapid decline was found in the low-level, slightly increasing trend group from WHR trajectory (0.43, 0.22-0.85).

CONCLUSION

FM and AF trajectories with consistent high levels and WHR trajectory with high level with U-shaped group are associated with low risks of incident cognitive impairment in older adults. Similarly, WHR trajectory with a low but slowly increasing trend is associated with a decreased risk of cognitive decline.

Functional Constipation is Associated with a Decline in Word Recognition 2 Years Later in Community-Dwelling Older Adults: The Korean Frailty and Aging Cohort Study

Background

Consumption and cognitive impairment are the most common health problems among older adults. This study aimed to determine the effects of functional constipation on cognitive decline in community-dwelling older adults.

Methods

This was a 2-year longitudinal analysis of Korean Frailty and Aging Cohort Study data, including 851 community-dwelling residents who participated in both the baseline and follow-up surveys. A neuropsychological test, the Consortium to Establish a Registry for Alzheimer's Disease Assessment Battery (CERAD-K), and the Korean version of the Frontal Assessment Battery (FAB) were used to evaluate cognitive function. Functional constipation was defined according to the ROME IV criteria. An analysis of covariance was used to identify the association between functional constipation and cognitive decline.

Results

Among the 851 participants, 8.9% had functional constipation. The patients in the constipation group were more likely to have low physical activity (15.8% vs. 8.8%), polypharmacy (61.8% vs. 45.5%), and depression (30.3% vs. 17.4%) than the non-constipation group. After adjusting for potential confounding factors, including age, sex, education years, low physical activity, polypharmacy, type 2 diabetes mellitus, depression, and baseline Cognitive Function Test score, the mean changes in Word Recognition test scores from 2018 to 2020 were -0.07 and -0.54 in the non-constipation and constipation groups, respectively (p=0.007). Other cognitive function tests (Mini-Mental State Examination, word list memory, word list recall, digit span, trail-making test, and FAB) did not show any difference in decline between the two groups (p>0.05).

Conclusions

Functional constipation at baseline was associated with a decline in word recognition after 2 years.

Obesity is associated with greater cognitive function in patients with type 2 diabetes mellitus

BACKGROUND

The impact of obesity on cognitive function in patients with type 2 diabetes mellitus (T2DM) remains controversial. This study aimed to evaluate whether obesity, assessed by body mass index (BMI) was associated with cognitive function among T2DM patients and whether the effect of obesity on cognitive function was through brain structure.

METHODS

This was a post-hoc analysis of the Action to Control Cardiovascular Risk in Diabetes-Memory in Diabetes (ACCORD-MIND) study. The cognitive test battery included the Digit Symbol Substitution Test (DSST), Mini-Mental State Exam (MMSE), Rey Auditory Verbal Learning Test (RAVLT), and STROOP test, which were administered at baseline, and at 20, 40, and 80 months. A subgroup (n = 614) of the ACCORD-MIND study underwent MRI scanning at baseline and at 40 and 80 months. The total brain volume (TBV), abnormal white matter volume (AWM), abnormal gray matter volume (AGM), and abnormal basal ganglia volume (ABG) were estimated. The outcomes of this study were cognitive function and brain structure.

RESULTS

In the adjusted analyses, BMI was positively associated with the MMSE (β:0.08, 95%CI,0.01-0.16, per standard deviation [SD] increase) and RAVLT scores (β:0.09, 95%CI,0.01-0.18). It was also associated with a greater TBV (β:7.48, 95%CI,0.29-14.67). BMI was not associated with the DSST or STROOP scores, and AWM, AGM, ABG. Mediation analysis found that the effect of BMI on MMSE/RAVLT was mediated through TBV.

CONCLUSION

Obesity may be associated with greater cognitive function and the effect of BMI on cognitive function may be mediated by TBV among patients with T2DM.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov, identifier NCT00000620.

Truncal Fat and Frailty Are Important Predictors of Cognitive Performance among Aging Adults with Obesity

OBJECTIVES

To explore associations among cognition, frailty, and obesity in older adults.

DESIGN

Descriptive, secondary analysis of baseline data from two related lifestyle intervention trials.

SETTING

Clinical study open to civilian population through the Center for Translational Research on Inflammatory Diseases at the Veterans Affairs Medical Center in Houston, TX.

PARTICIPANTS

One hundred eight community-dwelling adults with obesity, aged 65 or older, recruited consecutively from two lifestyle intervention trials.

MEASUREMENTS

Cognition was assessed using Composite Age-Adjusted Scale Score from the National Institutes of Health Toolbox Cognition Battery: Obesity was assessed by body mass index (BMI) and also by truncal fat mas via dual energy x-ray absorptiometry. Frailty was assessed using the Physical Performance Test.

RESULTS

A significant linear regression model for cognition revealed frailty as the strongest predictor, followed by sex, and then truncal fat (R2=0.340, p<0.001).

CONCLUSION

Cognition among community-dwelling older adults with obese BMI may worsen with greater truncal fat mass. Frailty appears to be an important predictor of cognitive performance in this population.

Screening for mild cognitive impairment in people with obesity: a systematic review

OBJECTIVE

Recent evidence demonstrates that obesity is associated with developing cognitive impairment. However, evidence related to the assessment of mild cognitive impairment (MCI) in people with obesity is limited. Therefore, this systematic review aimed to examine evidence concerning the screening of MCI in people with obesity from the general population.

METHOD

We conducted a systematic search of CINHAL, EMBASE, MEDLINE, PsycINFO and PubMed electronic databases for observational studies to assess MCI in people with obesity from the general population. PRISMA guideline was followed. The articles published from January 2011 to July 2021 were included.

RESULTS

Database search found 3104 sources. After the screening process, two articles from China and Egypt were included. The main age groups assessed were middle-aged adulthood and older adulthood. There were no studies undertaken in young adults or across the life span. Obesity was assessed by body mass index. MCI was assessed by cognitive screening tools; Mini-mental State Examination and Addenbrooke's Cognitive Examination. The prevalence of MCI in people with obesity was 18.5 % and 42.9 % in Chinese and Egyptian studies, respectively. Only one study supported a positive association between MCI and obesity.

CONCLUSIONS

Limited studies were found on screening MCI in people with obesity in the general population. The available evidence was not adequate to explain the overall prevalence, possible associations, and the best tool for assessing MCI in people with obesity. Expanding screening studies for MCI in people with obesity in the general population is essential.