Body mass index, performance on activities of daily living and cognition: analysis in two different populations

Healthy aging meta-analyses and scoping review of risk factors across Latin America reveal large heterogeneity and weak predictive models

Models of healthy aging are typically based on the United States and Europe and may not apply to diverse and heterogeneous populations. In this study, our objectives were to conduct a meta-analysis to assess risk factors of cognition and functional ability across aging populations in Latin America and a scoping review focusing on methodological procedures. Our study design included randomized controlled trials and cohort, case-control and cross-sectional studies using multiple databases, including MEDLINE, the Virtual Health Library and Web of Science. From an initial pool of 455 studies, our meta-analysis included 38 final studies (28 assessing cognition and 10 assessing functional ability, n = 146,000 participants). Our results revealed significant but heterogeneous effects for cognition (odds ratio (OR) = 1.20, P = 0.03, confidence interval (CI) = (1.0127, 1.42); heterogeneity: I2 = 92.1%, CI = (89.8%, 94%)) and functional ability (OR = 1.20, P = 0.01, CI = (1.04, 1.39); I2 = 93.1%, CI = (89.3%, 95.5%)). Specific risk factors had limited effects, especially on functional ability, with moderate impacts for demographics and mental health and marginal effects for health status and social determinants of health. Methodological issues, such as outliers, inter-country differences and publication bias, influenced the results. Overall, we highlight the specific profile of risk factors associated with healthy aging in Latin America. The heterogeneity in results and methodological approaches in studying healthy aging call for greater harmonization and further regional research to understand healthy aging in Latin America.

Nutrition risk and cognitive performance in community-living older adults without cognitive impairment: a cross-sectional analysis of the Canadian Longitudinal Study on Aging

Malnutrition is correlated with poor cognition; however, an understanding of the association between nutrition risk, which precedes malnutrition, and cognition is lacking. This study aimed to determine if nutrition risk measured with the SCREEN-8 tool is associated with cognitive performance among cognitively healthy adults aged 55+, after adjusting for demographic and lifestyle covariates. Sex- and age-stratified analyses were also explored. Baseline data from the Canadian Longitudinal Study on Aging was used. Cognition was determined using a 6-measure composite score based on four executive functions and two memory tasks, taking into account age, sex, and education. Multivariable linear regression was performed while adjusting for body mass index (BMI), lifestyle, and health covariates in the entire sample (n = 11 378) and then stratified by sex and age. Approximately half of participants were female (54.5%) aged 65+ (54.1%). Greater nutrition risk was associated with poorer cognitive performance in the entire sample (F[1, 11 368] = 5.36, p = 0.021) and among participants aged 55-64 (n = 5227; F[1, 5217] = 5.45, p = 0.020). Sex differences in lifestyle and health factors associated with cognition were apparent, but nutrition risk was not associated with cognition in sex-stratified models. Based on this analysis, there may be an association between nutrition risk and cognitive performance in older adults. When screening for either cognitive impairment or nutrition risk, complementary assessments for these conditions is warranted, as early intervention may provide benefit.

Association between body mass index and cognitive impairment in Chinese older adults

Background

The association between body mass index (BMI) and the risk of cognitive impairment remains uncertain. Relatively few studies have analyzed the dose-response relationship between BMI and cognitive impairment. This article utilized nationally representative longitudinal data to assess the association between BMI and cognitive impairment in Chinese older adults.

Objective

The present study aimed to analyze the association between BMI and cognitive impairment in Chinese older people, including an investigation of gender differences and the dose-response relationship.

Methods

Data were obtained from the China Health and Retirement Longitudinal Study database in 2015 and 2018. The present study used logistic regression to analyze the relationship between baseline BMI and cognitive impairment, and adopted a restricted cubic spline model to plot dose-response curves for baseline BMI and prevalence of risk of cognitive impairment.

Results

The mean BMI of the survey population was 23.48 ± 3.66 kg/m2, and the detection rate of cognitive impairment was 34.2%. Compared to the normal weight group (18.5 ≤ BMI < 23.9 kg/m2), the odds ratio (OR) for cognitive impairment was 1.473 (95% CI: 1.189-1.823) in the underweight group (BMI < 18.5 kg/m2), whereas the corresponding OR was 0.874 (95% CI: 0.776-0.985) for the overweight or obese group (BMI ≥ 24.0 kg/m2) after adjusting for confounders. Gender subgroup analysis showed that overweight or obese older women were less likely to develop cognitive impairment (OR = 0.843; 95% CI: 0.720-0.987). The results of the restricted cubic spline analysis revealed a curvilinear L-shaped relationship between BMI and the risk of cognitive impairment (P non-linearity <0.05). In particular, the risk of cognitive impairment was higher at a lower baseline BMI. In contrast, BMI in the range of 23.2-27.8 kg/m2 was associated with a decreased risk of cognitive impairment.

Conclusion

BMI is a dose-dependent related factor for cognitive impairment in Chinese older adults. Being underweight is a risk factor for the development of cognitive impairment, while being overweight or obese is less likely to have cognitive impairment, particularly in female older people. Keeping BMI ranging from 23.2-27.8 kg/m2 in older adults can help maintain cognitive function.

The impacts of social determinants of health and cardiometabolic factors on cognitive and functional aging in Colombian underserved populations

Global initiatives call for further understanding of the impact of inequity on aging across underserved populations. Previous research in low- and middle-income countries (LMICs) presents limitations in assessing combined sources of inequity and outcomes (i.e., cognition and functionality). In this study, we assessed how social determinants of health (SDH), cardiometabolic factors (CMFs), and other medical/social factors predict cognition and functionality in an aging Colombian population. We ran a cross-sectional study that combined theory- (structural equation models) and data-driven (machine learning) approaches in a population-based study (N = 23,694; M = 69.8 years) to assess the best predictors of cognition and functionality. We found that a combination of SDH and CMF accurately predicted cognition and functionality, although SDH was the stronger predictor. Cognition was predicted with the highest accuracy by SDH, followed by demographics, CMF, and other factors. A combination of SDH, age, CMF, and additional physical/psychological factors were the best predictors of functional status. Results highlight the role of inequity in predicting brain health and advancing solutions to reduce the cognitive and functional decline in LMICs.

Long-term care units: a Portuguese study about the functional profile

Aim: In this study, we analyze the relationship between the functional profile of older people admitted to long-term care units in Portugal and some demographic variables such as education level, sex, and age as well as the emotional state of mind. Methods: A sample of 59,516 older people from the National Network of Integrated Continuous Care of Portugal were analyzed in this longitudinal study. All the retrospective data of the older people were collected during the period of hospitalization at the long-term care units. The database records of these units were analyzed, and a functional profile spanning the period of hospitalization was calculated. Results: Activities of daily living and cognitive states improved, in the first 90 days of hospitalization, while mobility and instrumental activities of daily living worsened for the same period of 90 days. Generally, there was a decline in all domains after 450 days of hospitalization. The older women that did not attend school, those over 85 years old, and those who suffered from anxiety were pre-dominantly placed in the group of those with greater dependence (severe/complete dependence). Conclusion: The participants hospitalized between 90 and 360 days presented the best results in the long-term care units of the National Network of Integrated Continuous Care of Portugal. With this study, we highlight the importance of evaluating the functional status of persons in long-term hospitalizations and the influence exerted by the level of education on the recovery and rehabilitation of dependence.

Associations of lifestyle with physical, hearing, visual, and mental functional impairments among older adults: Findings from two prospective cohort studies

OBJECTIVE

To examine the associations between lifestyle habits and functional impairments among older adults.

METHODS

The study includes 20,545 women and 14,374 men aged 70 years or older at the time of the function assessment. Participants were from two prospective cohort studies: the Shanghai Women's Health Study (SWHS, enrollment from 1996 to 2000) and the Shanghai Men's Health Study (SMHS, enrollment from 2002 to 2006). Lifestyle information was collected at study enrollment and a healthy lifestyle score (HLS) was derived. Functional impairment information was collected at the follow-up survey conducted in 2012-2017. Logistic regression analyses were applied to estimate the associations of HLS with functional impairments.

RESULTS

The average age at lifestyle and functional impairment assessment was 62.3 (range: 49.9-70.9) and 77.7 (range: 70.0-89.4) for women and 67.5 (range: 55.1-74.9) and 77.4 (range: 70.0-88.6) for men. After a median follow-up of 14.4 years, we found that the HLS was inversely associated with overall severe functional impairment: odds ratio (95% confidence interval), 0.78(0.71-0.86) and individual severe functional impairment: 0.67(0.62-0.73) for independent walking, 0.85(0.77-0.94) for hearing/vision, 0.79(0.70-0.88) for memory, and 0.74(0.67-0.82) for decision-making impairment, comparing the highest with the lowest HLS categories. Such associations were similar among individuals with/without cardiometabolic diseases at baseline. The associations between each lifestyle factor and functional impairments differed.

CONCLUSION

A healthy lifestyle was associated with reduced odds of physical and mental impairment among older Chinese adults, emphasizing the importance of promoting and maintaining a healthy lifestyle to prevent or postpone age-related functional impairments.

The Prevalence and Agreement of Sarcopenic Obesity Using Different Definitions and Its Association with Mild Cognitive Impairment

BACKGROUND

The consistent definition of sarcopenic obesity (SO) is limited, its association with mild cognitive impairment (MCI) has not been clarified.

OBJECTIVE

This study aimed to evaluate the prevalence and agreement of SO using different definitions and the association between SO and MCI.

METHODS

SO was diagnosed by the co-existence of sarcopenia defined by the Asia Working Group for Sarcopenia (AWGS) and obesity by body mass index (BMI), visceral fat area (VFA), waist circumference (WC), or body fat percentage (BF%). Cohen's kappa was used to assess the agreement between the different definitions. The association between SO and MCI was assessed using multivariable logistic regression.

RESULTS

Among 2,451 participants, the prevalence of SO ranged from 1.7% to 8.0% under different definitions. SO defined by AWGS and BMI (AWGS+BMI) showed fair agreements with the other three criteria (κ ranged from 0.334 to 0.359). The other criteria showed good agreements with each other. The κ statistics were 0.882 for AWGS+VFA and AWGS+BF%, 0.852 for AWGS+VFA and AWGS+WC, and 0.804 for AWGS+BF% and AWGS+WC, respectively. When using different diagnoses of SO, compared with the health group, the adjusted ORs of MCI for SO were 1.96 (95% CI: 1.29-2.99, SO: AWGS+WC), 1.75 (95% CI: 1.14-2.68, SO: AWGS+VFA), 1.94 (95% CI: 1.29-2.93, SO: AWGS+BF%), and 1.45 (95% CI: 0.67-3.12, SO: AWGS+BMI), respectively.

CONCLUSION

Using different obesity indicators combined with AWGS to diagnose SO, BMI had lower prevalence and agreement compared with other three indicators. SO was associated with MCI under different methods (WC, VFA, or BF%).

Gender differences in the correlation between body mass index and cognitive impairment among the community-dwelling oldest-old in China: a cross-sectional study

OBJECTIVE

This study investigates gender differences in the correlation between body mass index (BMI) and cognitive impairment among Chinese community-dwelling oldest-old.

SETTING

Twenty-three provinces in China. Participants' mini-mental state examination (MMSE) scores <24 were considered cognitive impairment. Furthermore, the assessment standards of BMI status were classified into four categories: obese (BMI >30), overweight (25≤BMI≤30), normal (18.5≤BMI<25) and underweight (BMI <18.5).

PARTICIPANTS

A total of 9218 older adults (age 80+) were included from the 2018 wave of Chinese Longitudinal Healthy Longevity Study.

METHODS

Cognitive impairment, BMI and other covariates consisted of the sociodemographic variables, health behaviours and health status were collected. Cognitive impairment was assessed by the MMSE. Inverse probability weighting procedure was adopted to deal with bias due to dropout.Logistic regression was conducted to examine the correlation between BMI and cognitive impairment.

RESULTS

Among 9218 respondents, 3837 were males. Overall, the percentage of participants with cognitive impairment was 44.7%, with 32.1% among males and 53.7% among females. After controlling for other variables, males who were either overweight or underweight and females who were underweight were found to have higher risk of cognitive impairment among the oldest-old. Age, education, economic status, physical activity, activities of daily living, hypertension as well as heart disease were the predicting factors of cognitive impairment.

CONCLUSIONS

The relationship between BMI and cognitive impairment differs between male and female oldest-old, suggesting that we should pay attention to different BMI groups and adopt precise prevention strategies based on gender.

Type 2 Diabetes Independent of Glycemic Control is Associated With Cognitive Impairments: Findings From NHANES

Examine the association between glycemic control and cognition. Included subjects ≥60 years who participated in the 2013 to 2014 National Health and Nutrition Examination Survey and completed one of the followings: Consortium to Establish a Registry for Alzheimer's Disease Word List (CERAD-WL), Animal Fluency (AF), Digit Symbol Substitution Test (DSST), and CERAD-Delayed Recall (CERAD-DR). Stratified participants into: No type 2 diabetes (T2D; N = 557), Controlled T2D (N = 41), Uncontrolled T2D (N = 120), and Untreated T2D (N = 86). Multiple regression was used to examine the association between variables. After adjusting for demographics and cardiovascular risk factors, Uncontrolled T2D was associated with lower DSST (β = -3.164, p = .04), and Untreated T2D was associated with a trend for having lower CERAD-DR (β = -.496, p = .06) scores. T2D, independent of glycemic control, is associated with cognitive impairment and this relationship is influenced by modifiable and non-modifiable risk factors.

Longitudinal transition of body mass index status and its associated factors among Chinese middle-aged and older adults in Markov model

Introduction

Body mass index (BMI) has a strong correlation with chronic diseases and all-cause mortality. However, few studies have previously reported the longitudinal transition of BMI status and its influential factors, especially among Chinese middle-aged and older adults.

Methods

This population-based cohort study involved 6,507 participants derived from the China Health and Retirement Longitudinal Study from 2011 to 2015, including objectively measured BMI recorded in 26,028 person-year of all observations followed up. Multistate Markov model was performed to estimate the BMI state transition intensity and hazard ratios of each potential exposure risk.

Results

The mean intensity of the population that shifted from normal to overweight was more than twice than shifted to underweight. Besides, a predicted probability was up to 16.16% that the population with overweight would suffer from obesity and more than half of the population with underweight would return to normal weight over a 6-year interval. The study also implied significant effects of baseline age, gender, marital status, education level, alcohol consumption, smoking, depression symptoms, and activities of daily living impairment on BMI status transition to varying degrees.

Conclusions

Findings of this study indicated that the mean transition probability between different BMI statuses varied, specific exposure factors serving as barriers or motivators to future transitions based on current BMI status was clarified for the health promotion strategies.

Threshold effects of body mass index on cognitive function and heterogeneity by sex and cardiovascular risk factors

Background

Disclosing the underlying relationship between body mass index (BMI) and cognitive decline is imperative for cognitive impairment prevention and early detection. Empirical studies have indicated the risk of abnormal BMI leading to cognitive impairment. However, the relative risk of underweight or overweight on cognitive function is obscure. This study investigated the asymmetric causal effect of BMI on cognitive decline below and above an unknown threshold and the heterogeneity in the threshold level and the magnitude of the threshold effect due to sex and cardiovascular risk factors.

Methods

This study used 2010–2018 panel data from the Korean Longitudinal Study of Aging that assessed sociodemographic and health-related trends in Korean middle-aged to older population. A generalized method of moments estimator of the panel threshold model was applied to estimate the potential nonlinear pattern between BMI and cognitive function.

Results

There was a threshold effect in the relationship between BMI and cognitive function. An increase in BMI below the threshold was associated with higher cognitive function, whereas a further increase in BMI above the threshold led to cognitive decline. The nonlinear pattern between BMI and cognitive function differed by sex and cardiovascular risk appearing more distinctively within men or the cardiovascular risk group.

Conclusions

The detrimental impact of being underweight or overweight on cognitive function is heterogeneous by sex or cardiovascular risk. For obese men or individuals with cardiovascular risk factors, maintaining adequate BMI should be highlighted to help prevent cognitive decline.