Body mass index and trajectories of cognitive decline among older Korean adults

The circadian syndrome is a predictor for cognition impairment in middle-aged adults: Comparison with the metabolic syndrome

AIMS

Circadian syndrome (CircS) is considered a better predictor for cardiovascular disease than the metabolic syndrome (MetS). We aim to examine the associations between CircS and MetS with cognition in Chinese adults.

METHOD

We used the data of 8546 Chinese adults aged ≥40 years from the 2011 China Health and Retirement Longitudinal Study. MetS was defined using harmonised criteria. CircS included the components of MetS plus short sleep and depression. The cut-off for CircS was set as ≥4. Global cognitive function was assessed during the face-to-face interview.

RESULTS

CircS and MetS had opposite associations with the global cognition score and self-reported poor memory. Compared with individuals without the CircS and MetS, the regression coefficients (95%CI) for global cognition score were -1.02 (-1.71 to -0.34) for CircS alone and 0.52 (0.09 to 0.96) for MetS alone in men; -1.36 (-2.00 to -0.72) for CircS alone and 0.60 (0.15 to 1.06) for MetS alone in women. Having CircS alone was 2.53 times more likely to report poor memory in men (95%CI 1.80-3.55) and 2.08 times more likely in women (95%CI 1.54-2.81). In contrast, having MetS alone was less likely to report poor memory (OR 0.64 (0.49-0.84) in men and 0.65 (0.52-0.81) in women). People with CircS and MetS combined were more likely to have self-reported poor memory.

CONCLUSIONS

CircS is a strong and better predictor for cognition impairment than MetS in Chinese middle-aged adults. MetS without short sleep and depression is associated with better cognition.

Sex differences in cognitive function trajectories and their determinants in older adults: Evidence from the Chinese longitudinal healthy longevity survey

OBJECTIVES

To examine sex differences in the cognitive trajectories of a nationally representative sample of older people living in China and to explore potential determinants of these trajectories.

METHODS

The study included 2230 women and 2171 men who were cognitively healthy and aged over 60 at the first observation from the Chinese Longitudinal Healthy Longevity Survey based on the 2008-2018 cohort. Cognitive function was measured using the Chinese version of the Mini-Mental State Examination (MMSE). Group-based trajectory modeling was used to identify potential heterogeneity of longitudinal changes over the 10 years in each gender. Logistic regression was used to investigate associations between baseline characteristics (age, education, fertility history, sleep length, physical activity, and health status and behaviors) and trajectory classes.

RESULTS

Three trajectories (labeled stable, slow decline, and rapid decline) were identified according to the changes in MMSE scores for both women and men. For the women, both the slow and rapid decline groups accounted for a larger proportion (14.7% and 11.0%, respectively) than the male decline groups (8.1% and 6.6%, respectively), and the women had a lower baseline MMSE score with a faster decline. In the multivariable logistic regression analyses, older age, less education, older age at first birth, poorer functional abilities, hearing impairment, and lower baseline MMSE scores were significantly associated with cognitive decline in both the female and male groups compared to the stable group. For the women, sleeping over 9 h was also associated with a rapid cognitive decline trajectory, while current exercise and being overweight/obese were protective factors against cognitive decline.

CONCLUSIONS

The women had an overall more serious cognitive decline than men. The potential determinants of cognitive decline identified in this study could be considered for developing specific intervention strategies aimed at promoting a healthy brain and preventing cognitive decline in different sexes, especially in low-income and developing countries.

Individual and dual trajectories of insomnia symptoms and body mass index before and after retirement and their associations with changes in subjective cognitive functioning

BACKGROUND

We examined individual and dual trajectories of insomnia symptoms and body mass index (BMI) before and after retirement, and their associations with changes in subjective cognitive functioning after retirement.

METHODS

We used the Helsinki Health Study's (n = 2360, 79% women, aged 40-60 at baseline, Finland) repeated surveys to identify the developmental patterns of insomnia symptoms and BMI (2000-2017) and changes in subjective cognitive functioning (2017-2022). We analysed the data using latent group-based dual trajectory modelling and logistic regression analysis.

RESULTS

Three latent groups were identified for insomnia symptoms (stable low, decreasing and increasing symptoms) and BMI (stable healthy weight, stable overweight and stable obesity). Insomnia symptoms were associated with declining subjective cognitive functioning and largely explained the effects in the dual models.

CONCLUSION

The association between dual trajectories of insomnia symptoms and BMI with subjective cognitive decline is dominated by insomnia symptoms.

Association between obesity, physical activity, and cognitive decline in Chinese middle and old-aged adults: a mediation analysis

BACKGROUND AND OBJECTIVES

Epidemiological evidence on obesity and cognitive decline in middle and old-aged individuals is controversial and the effect of physical activity in this chain is sparse and limited. This study aimed to characterize the association between obesity and cognitive decline and the mediating role of physical activity.

METHODS

Data from China Health and Retirement Longitudinal Study (CHARLS) were used, including 7,392 participants aged ≥ 45 years between 2011 and 2018. Cognitive function was assessed via episodic memory and mental status. The total score of cognitive function was the sum of the above two dimensions (0-31 points). The Group-based trajectory modeling (GBTM) was applied to identify the potential heterogeneity of longitudinal changes in cognitive function. Multivariable ordinal logistic regression was used to investigate associations between obesity and cognitive trajectories, taking body mass index (BMI) as the indicator of obesity. Mediation analysis was performed to examine the potential causal chain in which physical activity mediates the relationship between BMI and cognitive decline.

RESULTS

Of the 7,392 analyzed patients (mean [SD] age, 58.0 [8.5] years; 3,916 [53%] male), the median (interquartile range [IQR]) of BMI was 23.4 (21.1-26.0). Four trajectories were identified by the GBTM model, including the high stable (14.9%), the middle stable (46.0%), the middle decline (29.9%), and the low decline groups (9.2%). After controlling potential confounders, obesity was associated with the low decline groups compared with normal weight (adjusted OR 0.81; 95% CI, 0.70-0.94). Mediation analyses showed that only vigorous physical activity significantly explained 5.94% (95% CI, 0.29-11.60%) of the relationship between obesity and cognitive decline. Sensitivity analyses in different subgroups showed comparable results.

CONCLUSION

This study suggests that vigorous physical activity mediates less than 10% of the association between obesity and cognitive decline in middle and old-aged adults. Further studies are warranted to explore the potential factors related to the obesity paradox in the cognitive field.

Longitudinal association between oral function and underweight onset among community-dwelling older adults: Role of regular self-weighing

AIMS

Regular self-weighing is effective in weight management and may help to mitigate the risk of underweight among older adults. We examined which factors of oral function are associated with a risk for underweight among community-dwelling older adults and whether regular self-weighing can mitigate that risk.

METHODS

This was a cohort study. Self-administered questionnaires were mailed to 7665 older adults in March 2019 (response rate 74.3%) and 7591 in March 2020 (response rate 74.7%). Among those who responded to both surveys, 3594 older adults who were not underweight in March 2019 were included (follow-up rate: 59.2%). We examined the association between dysphagia, poor masticatory function, and dry mouth and the development of underweight, and whether regular self-weighing reduced the risk for underweight.

RESULTS

The average age ± standard deviation of participants was 71.1 ± 3.4 years. There was a significant association between swallowing difficulty and the occurrence of underweight (odds ratio = 1.65, p = .012). However, this relationship did not differ significantly with regular self-weighing (p = .477).

CONCLUSIONS

These study findings suggest that to prevent underweight among community-dwelling older adults, it is important to focus on those with poor swallowing function.

Association Between Body Mass Index and Cognitive Function Among Older Adults in India: Findings from a Cross-Sectional Study

OBJECTIVE

The study aimed to explore the association between body mass index (BMI) and cognitive function among older adults in India.

METHODS

Cross-sectional data on 21,000 older adults aged 60 years and older from the first wave of the Longitudinal Ageing Study of India (LASI), conducted in India during 2017-18, were used. Bivariate analysis and multivariate linear regression models were applied. The cognition tests include memory, orientation, arithmetic function, executive function, and object naming.

RESULTS

The mean overall cognition score was 24.6 in the study population. Further, BMI status showed a significant and positive association with cognition. The association of underweight with poor cognition (β=-0.72; 95% CI = -0.89, -0.54) whereas overweight (β = 0.57; 95% CI = 0.39, 0.75) and obese (β = 0.97; 95% CI = 0.68, 1.26) with better cognition remained statistically significant after adjusting for sociodemographic, health-related behavior, and health covariates. The mean cognition score of female older adults was always lower than male older adults with normal BMI, irrespective of their BMI categories.

CONCLUSIONS

This study shows that an underweight BMI is associated with poor cognition in both male and female older adults. In the context of providing health care for older individuals, underweight individuals should be given more attention in India.

Examining the heterogeneity by employment status in dynamics between BMI and cognition: a longitudinal cohort study of the Korean aging population

PURPOSE

This study investigated the potential heterogeneity by employment status in the relationship between body mass index (BMI) trajectory and cognitive function among an aging population.

METHODS

We analyzed 2010-2018 cohort data from the Korean Longitudinal Study of Aging involving 4889 individuals aged over 45. We used statistical techniques of quadratic terms, interaction terms, time-invariant unobserved fixed effects, and time-lag effects to estimate the dynamic and interactive relationships among study variables.

RESULTS

The effect of BMI on cognitive function was heterogeneous based on employment status. For the nonemployed group, the impact of BMI on cognitive function showed an inverted U-shape with a turning point (BMI 25); a higher BMI (up to 25) was associated with higher cognitive function, but further increases beyond this threshold led to decreased cognitive function. For the employed group, however, the impact of BMI on cognitive function was nonsignificant. The nonlinear effect of BMI on cognitive function for the nonemployed group was robust across various subgroups and specifications.

CONCLUSIONS

The findings highlight the risk of obesity (BMI ≥ 25) on cognitive decline, particularly among nonemployed individuals. This illuminates the critical role of labor activity in regulating the impact of BMI on cognitive function among an aging population.

Associations Between Body Mass Index and Cognitive Change in the ACTIVE Study: Variations by Race and Social Determinants of Health

Objectives: The current study examines relationships between Body Mass Index (BMI) and cognitive performance and change in processing speed, memory, and reasoning, while accounting for variations by race and the influence of social determinants of health. Methods: Secondary data analysis of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study, which included participants who self-identified as African American or Black (n = 728) and White (n = 2028). Latent growth curve modeling was used to assess study aims. Results: Increases in BMI were associated with less cognitive decline over 10 years across each cognition domain. Race moderation effects were noted for speed and memory. Relationships between BMI and cognitive trajectories were mediated by economic stability for speed and reasoning. Discussion: Overall, these findings are consistent with the "obesity paradox." Further research is needed to elucidate patterns of results by race.

Executive Attentional Dyscontrol as a Core Cognitive and Behavioral Feature of Individuals with Obesity and Cardiovascular Disease: A Cross-Sectional Investigation

Executive attention as a frontal domain ability that is effective in potentially blocking distracting information, reconciling conflicts among simultaneous attentional demands, and regulating impulsive behavior may be impaired in individuals with obesity and cardiovascular disease (CVD). This study aimed (i) to explore the presence of selected cognitive (global cognitive impairment, sensitivity to interference, and attention) and psychological (quality of life, depression, anxiety, and impulsivity) dimensions and (ii) to examine the interactive relationship between attentional dyscontrol-both as a psychological and as a cognitive measure-and the above-mentioned variables in a sample of patients with CVD attending a cardiac rehabilitation program across different body mass index (BMI) levels. Clinical information of 104 patients with CVD was retrospectively collected. Participants were classified into three groups according to their BMI as follows: normal weight (NW = 30), overweight (OW = 19), and obese (OB = 55). Individuals with CVD and a higher BMI showed problems in controlling executive attention-through both neuropsychological and behavioral measures. Specifically, OB patients demonstrated reduced sensitivity to cognitive interference, lower capabilities in divided attention during visual-tracking tasks, and greater impulsivity compared to NW patients. This behavioral characteristic was also found to be correlated with higher levels of anxiety and depression and a lower quality of life. Implications for cognitive rehabilitation were discussed to offer directions for better management of patients with CVD and obesity.

A comparison of the five-minute cognitive test with the mini-mental state examination in the elderly for cognitive impairment screening

The five-minute cognitive test (FCT) is a novel cognitive screening method with the quick and reliable merit for detecting cognitive impairment at an early stage. The diagnostic power of FCT in differentiating subjects with cognitive impairment from people with cognition in a normal range was demonstrated effective as that of the Mini-Mental Status Evaluation (MMSE) in a previous cohort study. Here, we analyzed the effect of sociodemographic and health-related factors on FCT performance and further investigated the consistency of FCT. Then, we compared the correlation of subitem scores of FCT or MMSE with a comprehensive battery of neuropsychological tests that focus on specific domains of cognition. Finally, the association of the total FCT scores with the volumes of brain subregions was investigated. There were 360 subjects aged 60 years or above enrolled in this study, including 226 adults with cognitive abilities in normal range, 107 subjects with mild cognitive impairment (MCI) and 27 mild Alzheimer's disease (AD). The results showed that the total FCT scores was negatively associated with increasing age (β = -0.146, p < 0.001), and positively associated with education attainment (β = 0.318, p < 0.001), dwelling condition with family (β = 0.153, p < 0.001) and the Body Mass Index (β = 1.519, p < 0.01). The internal consistency of the FCT (Cronbach's α) was 0.644. The sub-scores of FCT showed a significant correlation with other specific neuropsychological tests. Impressively, the total FCT scores showed a significantly positive association with the volumes of hippocampus related subregions (r = 0.523, p < 0.001) and amygdala (r = 0.479, p < 0.001), but not with cerebellum (r = 0.158, p > 0.05) or subcortical subregions (r = 0.070, p > 0.05). Combining with previous data, FCT is a reliable and valid cognitive screening test for detecting cognitive impairment in a community setting.

Dietary Total Antioxidant Capacity and Cognitive Function in Older Adults in the United States: The NHANES 2011-2014

OBJECTIVES

Oxidative stress level takes part in the development of cognitive decline. However, the association between total antioxidant capacity (TAC) from diet and cognitive function is controversial. The aim of this study was to investigate the relationship between TAC and the cognitive function of older adults in the U.S.

DESIGN

A cross-sectional study.

SETTING

National Health and Nutrition Examination Surveys database.

PARTICIPANTS

2712 older adults aged over 60 years.

MEASUREMENTS

TAC was calculated from 8 antioxidative vitamins based on the reference values for vitamin C equivalent antioxidant capacity obtained from individuals' 24 h dietary recall. Four memory-related assessments were employed [Immediate Recall test (IRT), Delayed Recall test (DRT), Animal Fluency test (AFT), and Digit Symbol Substitution test (DSST)].

RESULTS

Among the 2712 participants, the median age was 68 years, and 50.4% were women. Participants in the group with higher TAC levels had relatively higher IRT, AFT and DSST scores (P=0.025, P=0.008, P<0.001, respectively). In adjusted weighted linear regression, log-transformed TAC was positively associated with AFT (β=1.10, 95%CI: 0.51, 1.70) and DSST (β=2.81, 95%CI: 1.16, 4.45). Compared with the first quartile, the participants in the second (Q2 vs. Q1, OR=0.66, 95%CI: 0.43,1.02) and fourth quartile (Q4 vs. Q1, OR=0.47, 95%CI:0.28, 0.78) of log-transformed TAC showed a decreased risk of impaired cognitive function (ICF) after adjusting for confounders. The dose-response analysis indicated a gradual descent in the risk of ICF as TAC increases. Diabetes mellitus (DM) mediated part of the effect of TAC on ICF. The relationship between TAC and ICF was more pronounced in subjects with DM (Q4 vs Q1, OR=0.36, 95%CI:0.17, 0.74).

CONCLUSION

Our findings support that higher dietary antioxidant potential was related to a decreased risk of cognitive dysfunction, particularly in the subjects with DM who may have oxidative injury. DM was one of the factors mediating the effect of TAC on ICF.

Body mass index and trajectories of the cognition among Chinese middle and old-aged adults

This study aims to investigate the association between trajectories of the cognition and body mass index (BMI) among Chinese middle and old-aged adults. A total of 5693 adults (age 45 +) whose cognitive score is higher than average at the baseline were included from China Health and Retirement Longitudinal Study (CHARLS:2011–2015). Cognitive function was measured by Mini-mental state examination (MMSE) in Chinese version. The Group-based trajectory modeling (GBTM) was adopted to identify the potential heterogeneity of longitudinal changes over the past 5 years and to investigate the relationship between baseline BMI and trajectories of cognitive function. Three trajectories were identified in results: the slow decline (37.92%), the rapid decline (6.71%) and the stable function (55.37%). After controlling for other variables, underweight (BMI < 18.5 kg/m2) was associated with the rapid and slow decline trajectories. Obesity (BMI > 28 kg/m2) was associated with the slow decline trajectory. High-risk people of cognitive decline can be screened by measuring BMI.

Association of Body Mass Index and Plant-Based Diet with Cognitive Impairment among Older Chinese Adults: A Prospective, Nationwide Cohort Study

To examine the association of body mass index (BMI) and a plant-based diet (PBD) with cognitive impairment in older adults, this cohort study used data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a national, community-based, longitudinal, prospective study in China. Cognitive function was evaluated via the Mini-Mental State Examination (MMSE). Diet was assessed using a simplified food frequency questionnaire (FFQ), and PBD patterns were estimated using the overall plant-based diet index (PDI), the healthful plant-based diet index (hPDI), and the unhealthful plant-based diet index (uPDI). BMI was measured objectively during the physical examination. Cox proportional hazard models and restricted cubic spline analyses were used. A total of 4792 participants with normal cognition at baseline were included, and 1077 participants were identified as having developed cognitive impairment during the 24,156 person-years of follow-up. A reverse J-shaped association was observed between BMI and cognitive impairment (p = 0.005 for nonlinearity). Participants who were overweight (HR = 0.79; 95% CI 0.66–0.95) and obese (HR = 0.72; 95% CI 0.54–0.96) had a decreased risk of cognitive impairment, while those who were underweight (HR = 1.42; 95% CI 1.21–1.66) had an increased risk. Lower PDI, lower hPDI, and higher uPDI were associated with an increased risk of cognitive impairment (HR = 1.32; 95% CI 1.16–1.50 for PDI; HR = 1.46; 95% CI 1.29–1.66 for hPDI; HR = 1.21; 95% CI 1.06–1.38 for uPDI). The protective effect of being overweight on cognitive impairment was more pronounced among participants with a higher PDI (HR = 0.74; 95% CI 0.57–0.95) than those with a lower PDI (HR = 0.87; 95% CI 0.67–1.12), among participants with a higher hPDI (HR = 0.73; 95% CI 0.57–0.94) than those with a lower hPDI (HR = 0.93; 95% CI 0.72–1.10), and among participants with a lower uPDI (HR = 0.61; 95% CI 0.46–0.80) than those with a higher uPDI (HR = 1.01; 95% CI 0.80–1.27). Our results support the positive associations of overweight status, obesity, an overall PBD, and a healthful PBD with cognitive function in older adults. A lower adherence to an overall PBD, a healthful PBD, and a higher adherence to an unhealthful PBD may attenuate the protective effect of being overweight on cognitive function.

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.

Association between mixed exposure of phthalates and cognitive function among the U.S. elderly from NHANES 2011-2014: Three statistical models

BACKGROUND

Studies on the relationship between phthalate exposure and cognition in adults are sparse and inconsistent. These studies only assessed their association of single phthalates for one-time and the tools for assessing cognitive function were different.

OBJECTIVE

We aimed to examine the association between mixed phthalates and cognition in the U.S elderly using three statistical models.

METHODS

The generalized linear (GLM), weighted quantile sum (WQS), and Bayesian kernel machine regression (BKMR) models were used to evaluate the associations between mixed phthalates and the standardized z-scores of four cognitive tests [Immediate Recall test (IRT), Delayed Recall test (DRT), Animal Fluency test (AFT), and Digit Symbol Substitution test (DSST)] in participants aged over 60 years from NHANES 2011-2014.

RESULTS

835 individuals were included and the median raw scores of IRT, DRT, AFT, and DSST were 19 (IQR: 16-23), 6 (IQR: 5-8), 16 (IQR: 13-20), 46 (IQR: 35-59). In adjusted GLM, negative associations were observed between MECPP, MnBP, MCOP, MCPP, and the IRT z-scores; MCPP, MBzP, and the DRT z-scores. Positive relationships were found between MCOP, MCPP, and the AFT z-scores; MCPP and the DSST z-scores. The WQS index was associated with the IRT z-scores (β(95%CI): -0.069(-0.118, -0.020)), where MCPP weighted the highest. In the BKMR, negative overall trends between the mixture and the IRT, DRT z-scores were observed when the mixture was at 40th to 65th percentile, 65th percentile or above it, respectively, where MnBP and MBzP drove the main effect of the mixture.

CONCLUSION

This study is an academic exploration of the association between phthalates exposure and cognitive function, suggesting that exposure to phthalates might be associated with bad performance in IRT and DRT in the U.S. elderly.

Association of Low Muscle Mass With Cognitive Function During a 3-Year Follow-up Among Adults Aged 65 to 86 Years in the Canadian Longitudinal Study on Aging

IMPORTANCE

Cross-sectional studies have shown that combined low muscle mass and strength are associated with cognitive impairment. Whether low muscle mass, reflective of physiologic reserve, is independently associated with faster cognitive decline remains unknown.

OBJECTIVE

To investigate the associations between low muscle mass and cognitive decline in 3 distinct domains among adults aged at least 65 years.

DESIGN, SETTING, AND PARTICIPANTS

The Canadian Longitudinal Study on Aging is a prospective population-based cohort study of community-dwelling adults. Enrollment occurred from 2011 to 2015 with a 3-year follow-up. Analyses for this study were conducted on those aged at least 65 years from April 24 to August 12, 2020.

EXPOSURE

Appendicular lean soft tissue mass (ALM) was assessed by dual energy x-ray absorptiometry. Low ALM was identified using the sex-specific Canadian cut points.

MAIN OUTCOMES AND MEASURES

Memory was assessed using the Rey auditory verbal learning test. Executive function was assessed using the mental alternation test, Stroop high interference (words/dot) test, the animal fluency test, and the controlled oral word association test. Psychomotor speed was assessed using computer-administered choice reaction time. Composite scores by domain were created.

RESULTS

Of 8279 participants, 4003 (48%) were female, 8005 (97%) were White, and the mean (SD) age was 72.9 (5.6) years. A total of 1605 participants (19.4%) had low ALM at baseline. Participants with low ALM were older, had lower body mass index and physical activity level. The presence of low ALM at baseline was associated with faster 3-year cognitive decline in executive functions and psychomotor speed from multiple linear regressions. After adjusting for covariates including age, level of education, percentage body fat, and handgrip strength, low ALM remained independently associated with executive function decline (standardized β: -0.032; P = .03) only. Low ALM was not associated with memory.

CONCLUSIONS AND RELEVANCE

This cohort study found longitudinal associations between low ALM and cognition in aging. Identification of older adults with low muscle mass, a targetable modifiable factor, may help estimate those at risk for accelerated executive function decline. Further longer-term investigation of associations is warranted.

Interpreting the Evidence of Body Mass Index in Relation to Mental Health Status in Community-Dwelling Older Adults

INTRODUCTION

Maintaining a better physical and mental health status is an important issue for older adults in their later life. Thus, the study's purpose was to evaluate the association between body mass index (BMI) and mental health status in older adults aged 65 years old or above residing in communities of Taipei City, Taiwan.

METHODS

We carried out secondary data analysis with data from a volunteer-based health examination project for older adults >65 years old residing in Taipei City from 2006 to 2010 with a retrospective study design. BMI, calculated by standardized measuring procedures for height and weight, and mental health status, evaluated by 5-item Brief Symptom Rating Scale (BSRS-5), were collected at their first visits of health examination. A BSRS-5 score ≥6 was considered an inferior mental health status for the outcome. In statistical analysis, univariable and multivariable logistic regressions were adopted to estimate the relative risk of inferior mental health status, treating BMI as the major exposure of interest.

RESULTS

A total of 90,576 subjects were involved, with a mean age of 73.38 years old (SD = 6.64 years) and 49.21% females. With confounders controlled, compared to normal or overweight (23 ≤ BMI <30), an adjusted OR of 1.23 (95% CI: 1.18, 1.29) on inferior mental health status was detected for the underweight group (BMI <23) significantly. Adjusted OR for those obese (BMI ≧30) was 0.87 (95% CI: 0.79, 0.96). Significantly elevated ORs of underweight were found for both genders, but the significantly protective effect of obese was only detected for females.

CONCLUSION

Keeping an appropriate weight or even being overweighted might be beneficial for older adults dwelling in the community, especially for males.

Body Mass Index, Waist Circumference, and Cognitive Decline Among Chinese Older Adults: A Nationwide Retrospective Cohort Study

Background

The reported associations between body mass index (BMI), waist circumference (WC), and cognitive decline are not consistent, especially in older adults.

Objective

This study aims to investigate the longitudinal associations of BMI, WC, and their change values with cognitive decline among Chinese adults aged 60 years and older and to examine the potential moderating effect of sex on these relationships.

Methods

The participants in this study were from waves one to four (2011–2018) of the China Health and Retirement Longitudinal Study (CHARLS). Cognition function, BMI, and WC were measured at four examinations over 7 years. The interview-based cognitive assessments of memory, orientation and attention, and visuospatial ability were recorded. Standardized global cognitive scores were generated. BMI and WC were objectively measured. Mixed-effects models were performed to evaluate the associations.

Results

A final sample of 3,035 Chinese older adults [mean (SD) age, 66.94 (5.43) years; 40.16% (n = 1,219) women] were included. Higher BMI (estimate = 0.0107; SE = 0.0024; p < 0.0001) and WC (estimate = 0.0019; SE = 0.0006; p = 0.0037) were associated with slower cognition score decline over a 7-year follow-up, while greater BMI variability (estimate = −0.0365; SE = 0.0116; p = 0.0017) was related to faster cognition score decline. The results were not modified by sex. BMI-defined overweight (estimate = 0.0094; SE = 0.0043; p = 0.0298) was associated with a slower cognition score decline, and both large weight gain (estimate = −0.0266; SE = 0.0074; p = 0.0003) and large WC loss (estimate = −0.0668; SE = 0.0329; p = 0.0426) were associated with faster cognition score decline.

Conclusion

Among Chinese older adults, higher BMI, higher WC, and overweight are related to slower cognitive decline, while greater BMI variability, large weight gain, and large WC loss are associated with faster cognitive decline.

Study on Correlation between Body Cell Mass Index and Cognitive Impairment in Hemodialysis Maintaining Patients: A Cross-Sectional Study

Objective

To investigate the relationship between body cell mass index (BCMI) and cognitive impairment in maintaining hemodialysis (MHD) patients.

Methods

We collected the general materials, laboratory indexes, and physical measurement indexes of patients undergoing maintenance hemodialysis in hemodialysis centers of 20 tertiary and tertiary general hospitals in Guizhou Province from June to September 2020. The body composition was measured by bioelectrical impedance method, and the BCMI value was calculated. The subjects were divided into normal cognitive function group (score ≥27), mild cognitive impairment group (score 23-26), and severe cognitive impairment group (score <23). Two groups of people with normal cognitive function and cognitive impairment with similar baseline data (gender, age, and education) were obtained by propensity score matching (PSM).

Results

A total of 2008 subjects were included in this study, including 467 cases (23.3%) in the cognitive impairment group. A total of 814 cases were accurately matched after PSM. Multivariate logistic regression analysis showed that the incidence risk of the BCMI Q1 group was 8.99 times higher than that of the Q4 group (95% CI: 5.74 ∼ 14.09, P < 0.001). ROC curve analysis showed that the best threshold of BCMI for predicting cognitive impairment in MHD patients was 9.05, the sensitivity and specificity were 71.5% and 62.7%, respectively, and the area under the curve was 0.713 (95% CI: 0.678 ∼ 0.748, P < 0.001).

Conclusions

BCMI is related to cognitive impairment in MHD patients and has predictive value for the onset of cognitive impairment in MHD patients.

Association between the Erythrocyte Membrane Fatty Acid Profile and Cognitive Function in the Overweight and Obese Population Aged from 45 to 75 Years Old

Dietary fatty acid intake is closely related to the cognitive function of the overweight and obese population. However, few studies have specified the correlation between exact fatty acids and cognitive functions in different body mass index (BMI) groups. We aimed to explain these relationships and reference guiding principles for the fatty acid intake of the overweight and obese population. Normal weight, overweight, and obese participants were recruited to receive a cognitive function assessment and dietary survey, dietary fatty acids intake was calculated, and the erythrocyte membrane fatty acid profile was tested by performing a gas chromatography analysis. The percentages of saturated fatty acids (SFAs) in the obese group were higher, while monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were lower than in the normal weight and overweight groups. In the erythrocyte membrane, the increase of n-3 PUFAs was accompanied by cognitive decline in the overweight group, which could be a protective factor for cognitive function in the obese group. High n-6 PUFAs intake could exacerbate the cognitive decline in the obese population. Dietary fatty acid intake had different effects on the cognitive function of overweight and obese people, especially the protective effect of n-3 PUFAs; more precise dietary advice is needed to prevent cognitive impairment.

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.

Association between body mass index, its change and cognitive impairment among Chinese older adults: a community-based, 9-year prospective cohort study

To examine the association of baseline body mass index (BMI) and BMI change with cognitive impairment among older adults in China. The study included data from the Chinese Longitudinal Healthy Longevity Study, a national community-based prospective cohort study from 2002 to 2018. Baseline BMI and BMI change were available for 12,027 adults aged older than 65 years. Cognitive impairment was defined as Chinese version of the Mini Mental State Examination score lower than 18. Multivariable Cox proportional hazard model was used. Among 12,027 participants (mean age was 81.23 years old and 47.48% were male), the proportion of underweight, normal, overweight and obese at baseline was 33.87%, 51.39%, 11.39% and 3.34%, respectively. During an average of 5.9 years' follow-up, 3086 participants (4.35 per 100 person-years) with incident cognitive impairment were identified. Compared with normal weight group, adjusted hazard ratio (AHR) for cognitive impairment was 0.86 (95% CI 0.75-0.99) among overweight group, whereas corresponding AHR was 1.02 (95% CI 0.94-1.10) in underweight and 1.01 (95% CI 0.80-1.28) in obese participants. Large weight loss (< -10%) was significantly associated with an increased risk of cognitive impairment (AHR, 1.42, 95% CI 1.29-1.56), compared to stable weight status group (-5% ~ 5%). In the restricted cubic spline models, BMI change showed a reverse J-shaped association with cognitive impairment. BMI-defined overweight, but not obesity, was associated with a lower risk of cognitive impairment among elderly Chinese adults, while large weight loss was associated with an increased risk. These findings are consistent with weight loss in the prodromal phase of dementia.

The dynamic association between body mass index and cognition from midlife through late-life, and the effect of sex and genetic influences

Body mass index (BMI) is associated with cognitive abilities, but the nature of the relationship remains largely unexplored. We aimed to investigate the bidirectional relationship from midlife through late-life, while considering sex differences and genetic predisposition to higher BMI. We used data from 23,892 individuals of European ancestry from the Health and Retirement Study, with longitudinal data on BMI and three established cognitive indices: mental status, episodic memory, and their sum, called total cognition. To investigate the dynamic relationship between BMI and cognitive abilities, we applied dual change score models of change from age 50 through 89, with a breakpoint at age 65 or 70. Models were further stratified by sex and genetic predisposition to higher BMI using tertiles of a polygenic score for BMI (PGSBMI). We demonstrated bidirectional effects between BMI and all three cognitive indices, with higher BMI contributing to steeper decline in cognitive abilities in both midlife and late-life, and higher cognitive abilities contributing to less decline in BMI in late-life. The effects of BMI on change in cognitive abilities were more evident in men compared to women, and among those in the lowest tertile of the PGSBMI compared to those in the highest tertile, while the effects of cognition on BMI were similar across groups. In conclusion, these findings highlight a reciprocal relationship between BMI and cognitive abilities, indicating that the negative effects of a higher BMI persist from midlife through late-life, and that weight-loss in late-life may be driven by cognitive decline.

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

BACKGROUND

With this study, we aim to determine the associations of the different categories of the body mass index (BMI) with activities of daily living (ADL) and cognitive performance in two different populations living in the community; Colombian and South Korean older adults.

METHODS

We performed a cross-sectional analysis of two surveys separately; The Survey on Health, Well-Being, and Aging in Colombia (SABE) (n = 23,343) and the Korean Longitudinal Study of aging (KLoSA) (n = 4556). Participants older than 50 years were selected from rural and urban areas achieving a representative sample. Here we investigated the association between BMI categories with function using zero-inflated negative binomial regressions, and with cognition using logistic regression models.

RESULTS

After adjustment, in Colombia, underweight was associated with an impaired score on the Mini-mental State Examination (MMSE) and worse performance in the instrumental activities of daily living (IADL). Also, being overweight was associated with a better score on the MMSE and the IADL. For both outcomes education level significantly influenced the predictions. In South Korea, there were no significant associations for cognition, IADL, or basic activities of daily living (BADL).

CONCLUSIONS

In the Colombian population, underweight, was associated with reduced cognitive performance and daily functioning. Additionally, being overweight but not obese was associated with better cognition and daily functioning. In South Korea, there were no significant associations between BMI and cognition, IADL, or BADL.

Changes in Body Mass Index Are Related to Faster Cognitive Decline Among African American Older Adults

BACKGROUND/OBJECTIVES

The purpose of this study was to: (1) examine relationships between body mass index (BMI) stability and cognitive decline in older African Americans; and (2) investigate differences in the relationships between women and men.

DESIGN

The present study is a secondary data analysis of the Minority Aging Research Study, which is a longitudinal, cohort study of risk factors for cognitive decline and Alzheimer's disease among older African Americans living in the Chicago, IL, area. The study entails annual clinical evaluations, including measures of 19 neuropsychological tests that represent five cognitive domains, including episodic, semantic, and working memory, perceptual speed, and visuospatial ability.

PARTICIPANTS

Participants (n = 671; mean age = 73.5 years; standard deviation = 6.2 years) were included in the present analysis if they were dementia free at baseline and completed at least two clinical evaluations, on average 1 year apart, that included valid cognitive and BMI assessments.

RESULTS

Mixed-effects models showed higher baseline BMI was related to slower global cognitive decline, whereas changes in BMI (instability) were related to faster global cognitive decline. These effects were the same for four of five cognitive domains and remained after controlling for various health characteristics. However, women and men did not differ in any of the relationships.

CONCLUSION

Higher BMI is related to slower cognitive decline in older African Americans, but greater BMI instability is related to faster decline. Stability of BMI should be considered in the cognitive aging of African Americans.

Trajectories of cognitive function and their determinants in older people: 12 years of follow-up in the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Cognitive decline in advanced age is closely related to dementia. The trajectory of cognitive function in older Chinese is yet to be fully investigated. We aimed to investigate the trajectories of cognitive function in a nationally representative sample of older people living in China and to explore the potential determinants of these trajectories.

METHODS

This study included 2,038 cognitively healthy persons aged 65-104 years at their first observation in the Chinese Longitudinal Healthy Longevity Survey from 2002 to 2014. Cognitive function was measured using the Chinese version of the Mini-Mental State Examination (MMSE). Group-based trajectory modeling was used to identify potential heterogeneity of longitudinal changes over the 12 years and to investigate associations between baseline predictors of group membership and these trajectories.

RESULTS

Three trajectories were identified according to the following types of changes in MMSE scores: slow decline (14.0%), rapid decline (4.5%), and stable function (81.5%). Older age, female gender, having no schooling, a low frequency of leisure activity, and a low baseline MMSE score were associated with the slow decline trajectory. Older age, body mass index (BMI) less than 18.5 kg/m2, and having more than one cardiovascular disease (CVD) were associated with the rapid decline trajectory.

CONCLUSION

Three trajectories of cognitive function were identified in the older Chinese population. The identified determinants of these trajectories could be targeted for developing prevention and intervention strategies for dementia.