Association Between Waist Circumference and Dementia in Older Persons: A Nationwide Population-Based Study

Association of waist-to-hip ratio adjusted for body mass index with cognitive impairment in middle-aged and elderly patients with type 2 diabetes mellitus: a cross-sectional study

BACKGROUND

Numerous reports indicate that both obesity and type 2 diabetes mellitus (T2DM) are factors associated with cognitive impairment (CI). The objective was to assess the relationship between abdominal obesity as measured by waist-to-hip ratio adjusted for body mass index (WHRadjBMI) and CI in middle-aged and elderly patients with T2DM.

METHODS

A cross-sectional study was conducted, in which a total of 1154 patients with T2DM aged ≥ 40 years were included. WHRadjBMI was calculated based on anthropometric measurements and CI was assessed utilizing the Montreal Cognitive Assessment (MoCA). Participants were divided into CI group (n = 509) and normal cognition group (n = 645). Correlation analysis and binary logistic regression were used to explore the relationship between obesity-related indicators including WHRadjBMI, BMI as well as waist circumference (WC) and CI. Meanwhile, the predictive power of these indicators for CI was estimated by receiver operating characteristic (ROC) curves.

RESULTS

WHRadjBMI was positively correlated with MoCA scores, independent of sex. The Area Under the Curve (AUC) for WHRadjBMI, BMI and WC were 0.639, 0.521 and 0.533 respectively, and WHRadjBMI had the highest predictive power for CI. Whether or not covariates were adjusted, one-SD increase in WHRadjBMI was significantly related to an increased risk of CI with an adjusted OR of 1.451 (95% CI: 1.261-1.671). After multivariate adjustment, the risk of CI increased with rising WHRadjBMI quartiles (Q4 vs. Q1 OR: 2.980, 95%CI: 2.032-4.371, P for trend < 0.001).

CONCLUSIONS

Our study illustrated that higher WHRadjBMI is likely to be associated with an increased risk of CI among patients with T2DM. These findings support the detrimental effects of excess visceral fat accumulation on cognitive function in middle-aged and elderly T2DM patients.

Associations of body habitus and its changes with incident dementia in older adults

BACKGROUND

This study examined the associations of body mass index (BMI) and waist circumference (WC), as well as their short- and long-term changes over time, with incident dementia in older individuals.

METHODS

Data came from 18,837 community-dwelling individuals aged 65+ years from Australia and the United States, who were relatively healthy without major cognitive impairment at enrolment. Anthropometric measures were prospectively assessed at baseline, as well as change and variability from baseline to year two (three time-points). In a subgroup (n = 11,176), self-reported weight at age 18 and 70+ years was investigated. Dementia cases satisfied DSM-IV criteria. Cox regression was used to examine the associations between anthropometric measures and incident risk of dementia.

RESULTS

Compared to normal weight, an overweight (HR: 0.67, 95%CI: 0.57-0.79, p < 0.001) or obese BMI (HR: 0.73, 95%CI: 0.60-0.89, p = 0.002), or a larger WC (elevated, HR: 0.71, 95%CI: 0.58-0.86, p < 0.001; highly elevated, HR: 0.65, 95%CI: 0.55-0.78, p < 0.001; relative to low) at baseline was associated with lower dementia risk. In contrast, substantial increases in BMI (>5%) over 2 years after baseline were associated with higher dementia risk (HR: 1.49, 95% CI: 1.17-1.91, p = 0.001). Increased dementia risk was also seen with an underweight BMI at baseline and a 2-year BMI decrease (>5%), but these associations appeared only in the first 4 years of follow-up. Compared to normal weight at both age 18 and 70+ years, being obese at both times was associated with increased dementia risk (HR: 2.27, 95%CI: 1.22-4.24, p = 0.01), while obesity only at age 70+ years was associated with decreased risk (HR: 0.70, 95%CI: 0.51-0.95, p = 0.02).

CONCLUSIONS

Our findings suggest that long-term obesity and weight gain in later life may be risk factors for dementia. Being underweight or having substantial weight loss in old age may be early markers of pre-clinical dementia.

Digging into the intrinsic capacity concept: Can it be applied to Alzheimer's disease?

Historically, aging research has largely centered on disease pathology rather than promoting healthy aging. The World Health Organization's (WHO) policy framework (2015-2030) underscores the significance of fostering the contributions of older individuals to their families, communities, and economies. The WHO has introduced the concept of intrinsic capacity (IC) as a key metric for healthy aging, encompassing five primary domains: locomotion, vitality, sensory, cognitive, and psychological. Past AD research, constrained by methodological limitations, has focused on single outcome measures, sidelining the complexity of the disease. Our current scientific milieu, however, is primed to adopt the IC concept. This is due to three critical considerations: (I) the decline in IC is linked to neurocognitive disorders, including AD, (II) cognition, a key component of IC, is deeply affected in AD, and (III) the cognitive decline associated with AD involves multiple factors and pathophysiological pathways. Our study explores the application of the IC concept to AD patients, offering a comprehensive model that could revolutionize the disease's diagnosis and prognosis. There is a dearth of information on the biological characteristics of IC, which are a result of complex interactions within biological systems. Employing a systems biology approach, integrating omics technologies, could aid in unraveling these interactions and understanding IC from a holistic viewpoint. This comprehensive analysis of IC could be leveraged in clinical settings, equipping healthcare providers to assess AD patients' health status more effectively and devise personalized therapeutic interventions in accordance with the precision medicine paradigm. We aimed to determine whether the IC concept could be extended from older individuals to patients with AD, thereby presenting a model that could significantly enhance the diagnosis and prognosis of this disease.

Relationship between cognitive function and weight-adjusted waist index in people ≥ 60 years old in NHANES 2011-2014

BACKGROUND

Widespread attention has been given to the detrimental effects of obesity on cognitive function. However, there is no evidence on the connection between low cognitive performance and the WWI (weight-adjusted waist index). This study looked into the connection between poor cognitive performance and the WWI in senior Americans.

METHODS

A cross-sectional research study was carried out with information from the NHANES 2011-2014. With multivariate linear regression models, the pertinence between the WWI and low cognitive function in persons older than 60 years was examined. The nonlinear link was described using threshold effect analyses and fitted smoothed curves. Interaction tests and subgroup analysis were also conducted.

RESULTS

The study had 2762 individuals in all, and subjects with higher WWI values were at greater risk for low cognitive function. In the completely adjusted model, the WWI was positively connected with low cognitive performance assessed by CERAD W-L (OR = 1.22, 95% CI 1.03-1.45, p = 0.0239), AFT (OR = 1.30, 95% CI 1.09-1.54, p = 0.0029), and DSST (OR = 1.59, 95% CI 1.30-1.94, p < 0.0001). The effect of each subgroup on the positive correlation between the WWI and low cognitive performance was not significant. The WWI and low cognitive performance as determined by CERAD W-L and AFT had a nonlinear connection (log-likelihood ratio < 0.05).

CONCLUSION

Among older adults in the United States, the risk of low cognitive performance may be positively related to the WWI.

Adherence to a healthy lifestyle and its association with cognitive impairment in community-dwelling older adults in Shanghai

Introduction

There is a growing body of recent literature linking the association of specific or multiple lifestyles with cognitive impairment, but most of these studies have been conducted in Western populations, and it is necessary to study multiple lifestyles and cognitive abilities in different populations, with the primary population of this study being a select group of community-dwelling older adults in Shanghai, China.

Methods

The sample included 2,390 community-dwelling Chinese participants. Their cognitive function was assessed using the Mini-Mental State Examination (MMSE). We defined a healthy lifestyle score on the basis of being non-smoking, performing ≥210 min/wk moderate/vigorous-intensity physical activity, having light to moderate alcohol consumption, eating vegetables and fruits daily, having a body mass index (BMI) of 18.5-23.9 kg/m2, and having a waist-to-hip ratio (WHR) <0.90 for men and <0.85 for women, for an overall score ranging from 0 to 6.

Results

Compared with participants with ≤2 healthy lifestyle factors, the adjusted odds ratio (OR) and 95% confidence interval (CI) for participants with 4, 5, and 6 healthy lifestyle factors were 0.53 (95% CI, 0.29-0.98), 0.40 (95% CI, 0.21-0.75), and 0.36 (95% CI, 0.16-0.79), respectively. Only WHR (OR = 0.54, 95% CI = 0.37-0.78) and physical activity (OR = 0.69, 95% CI = 0.51-0.92) were associated with cognitive impairment. A healthy lifestyle correlated with overall cognition (β = 0.066, orientation (β = 0.049), language ability (β = 0.060), delayed recall (β = 0.045) and executive function (β = 0.044) (P all < 0.05).

Conclusion

The study provides evidence on an inverse association between healthy lifestyles and cognitive impairment. We investigated whether healthy lifestyle was related to specific cognitive functions to provide a theoretical basis for accurate clinical prescription.

Weight loss and risk of dementia in individuals with versus without obesity

INTRODUCTION

Using nationwide cohort data, we aimed to elucidate whether baseline obesity altered the relationship between loss in body mass index (BMI) or waist circumference (WC) and risk of dementia.

METHODS

Among 9689 participants whose BMIs and WCs were repeatedly measured over 1 year, 1:1 propensity score matching was conducted between participants with and without obesity (n = 2976 per group, mean age 70.9). For each group, we explored the association between loss in BMI, or WC, and incidence of dementia during an approximately 4-year follow-up period.

RESULTS

BMI loss was associated with an increased risk of all-cause dementia and Alzheimer's disease in participants without obesity; however, this association was absent in participants with obesity. WC loss was associated with decreased Alzheimer's disease risk only in participants with obesity.

DISCUSSION

Only unfavorable loss (loss from non-obese state) in BMI, not WC, can be a metabolic biomarker of prodromal dementia.

Positive association between weight-adjusted-waist index and dementia in the Chinese population with hypertension: a cross-sectional study

PURPOSE

The links between obesity and dementia remain equivocal. Therefore, this study aimed to explore the association between weight-adjusted waist index (WWI), a new anthropometric indicator reflecting obesity, and dementia in the Chinese population with hypertension.

METHODS

A total of 10,289 participants with hypertension were enrolled in this cross-sectional study, a subset of the China H-type hypertension registry study. WWI was calculated as waist circumference (WC) divided by the square root of bodyweight. Mini-mental state examination (MMSE) scale was performed to evaluate the cognitive function. According to educational background, different MMSE cut-off values were applied to define dementia: < 24 for participants with ≥ 7 years of education, < 20 for those with 1-6 years of education, and < 17 for illiterate participants. Multivariable linear regression and multivariable binary logistic regression analyses were conducted to assess the associations between WWI and MMSE and dementia, respectively.

RESULTS

Overall, the mean age was 63.7 ± 9.7 years, and 49.0% were males. Multivariate linear regression analyses showed that WWI was negatively associated with MMSE (β, -1.09; 95% confidence interval [CI]: -1.24, -0.94). Consistently, multivariable binary logistic regression analyses found a positive association between WWI and the risk of dementia (odds ratio [OR], 1.45; 95% CI: 1.35, 1.56). Compared with individuals in quartile 1 of WWI, the adjusted β and OR values of WWI for MMSE and dementia were -2.28 (95% CI: -2.62, -1.94) and 2.12 (95% CI: 1.81, 2.48), respectively. Results of smoothing curve fitting confirmed the linear association between WWI and MMSE and dementia. Subgroup analysis showed a stronger association between WWI and dementia in participants with hypertension with midday napping.

CONCLUSION

WWI was independently and positively associated with dementia among the population with hypertension, especially in those with midday napping. The data suggests that WWI may serve as a simple and effective tool for the assessment of the risk of dementia in clinical practice.

Sex Differences in the Association Between Body Mass Index and Dementia Risk in Community-Dwelling Japanese People Aged 40-74 Years

BACKGROUND

The association between body mass index (BMI) and dementia risk is heterogeneous across age groups and might be influenced by sex.

OBJECTIVE

This study aimed to clarify sex differences in the association between BMI and dementia risk in community-dwelling people.

METHODS

This cohort study with an 8-year follow-up targeted 13,802 participants aged 40-74 years at baseline in 2011-2013. A self-administered questionnaire requested information on body size, including height, weight, and waist circumference (the values of which were validated by direct measurement), socio-demographics, lifestyle, and disease history. BMI was calculated and categorized as < 18.5 (underweight), 18.5-20.6 (low-normal), 20.7-22.6 (mid-normal), 22.7-24.9 (high-normal), 25.0-29.9 (overweight), and≥30.0 kg/m2 (obese). Incident cases of dementia were obtained from the long-term care insurance database. A Cox proportional hazards model was used to calculate multivariable-adjusted hazard ratios (HRs).

RESULTS

The mean age of participants was 59.0 years. In men, higher BMI was associated with lower dementia risk (fully-adjusted p for trend = 0.0086). In women, the association between BMI and dementia risk was U-shaped; the "underweight," "low-normal," and "overweight" groups had a significantly higher risk (fully-adjusted HR = 2.12, 2.08, and 1.78, respectively) than the reference ("high-normal" group). These findings did not change after excluding dementia cases which occurred within the first four years of the follow-up period.

CONCLUSION

Overweight/obese women, but not men, had an increased risk of dementia, suggesting that sex differences in adiposity might be involved in the development of dementia.

Associations Between Abdominal Obesity, Chewing Difficulty and Cognitive Impairment in Dementia-Free Chinese Elderly

OBJECTIVE

To investigate the independent and synergistic associations between abdominal obesity, chewing difficulty and cognitive impairment in a community-dwelling older adults sample in China.

METHODS

Cognitive function was measured by the 5 min- Montreal Cognitive Assessment (5 min-MoCA) and abdominal obesity was measured by A Body Shape Index (ABSI) in 572 participants recruited from local communities. Chewing difficulty was assessed via a self-report questionnaire. Linear regression and general logistic regression were performed to investigate the association of chewing difficulty and abdominal obesity with cognition.

RESULTS

Chewing difficulty score [β (95% CI) = -.30 (-.49, -.11)] and ABSI [β (95%CI) = -.30 (-.55, -.05)] were independently associated with worse performance on the 5 min-MoCA. Whilst ABSI was not associated with cognitive impairment, the co-existence of chewing difficulty and abdominal obesity [OR (95% CI) = 2.22 (1.18, 4.17)] was found associated with the presence of cognitive impairment.

CONCLUSION

Chewing difficulty and abdominal obesity were independently associated with cognition. Abdominal obesity and chewing may have an additive effect on cognitive function.

Recent Updates on Associations among Various Obesity Metrics and Cognitive Impairment: from Body Mass Index to Sarcopenic Obesity

Obesity and obesity-associated morbidity continues to be a major public health issue worldwide. Dementia is also a major health concern in aging societies and its prevalence has increased rapidly. Many epidemiologic studies have shown an association between obesity and cognitive impairment, but this relationship is not as well established as other comorbidities. Conflicting results related to the age and sex of participants, and the methodology used to define obesity and dementia may account for the uncertainty in whether obesity is a modifiable risk factor for dementia. More recently, sarcopenia and sarcopenic obesity have been reported to be associated with cognitive impairment. In addition, new mediators such as the muscle-myokine-brain axis and gut-microbiota-brain axis have been suggested and are attracting interest. In this review, we summarize recent evidence on the link between obesity and cognitive impairment, especially dementia. In particular, we focus on various metrics of obesity, from body mass index to sarcopenia and sarcopenic obesity.

Dynapenic abdominal obesity is associated with mild cognitive impairment in patients with cardiometabolic disease: a cross-sectional study

Background

Dementia is an important health issue for older people and requires early intervention in the mild cognitive impairment (MCI) stage to manage risk factors. Both dynapenia (DP) and abdominal obesity (AO) are associated with inflammation and oxidative stress, which may be involved in the pathogenesis of cognitive impairment. Therefore, in this cross-sectional study, we aimed to evaluate the association between MCI and dynapenic abdominal obesity (DAO), a combination of DP and AO.

Methods

A total of 417 older outpatients with cardiometabolic diseases without severe cognitive impairment were studied to compare cognitive function in four groups: control, DP, AO, and DAO groups. DAO was defined as the combination of DP (handgrip strength of < 28 kg and < 18 kg in men and women, respectively) and AO (waist circumference of ≥ 85 cm and ≥ 90 cm in men and women, respectively). MCI was defined as a score of ≤ 25 in the Japanese version of the Montreal Cognitive Assessment. Multiple regression analyses were performed to examine if MCI was independently associated with DAO, low handgrip strength, or high waist circumference.

Results

The DAO group obtained the lowest cognitive test scores and had the highest prevalence of MCI. Furthermore, after adjusting for covariates, the logistic regression analysis showed that patients in the DAO group were at an increased risk of MCI (odds ratio [OR] = 3.98, 95% confidence interval [CI]: 1.15–13.77). Further logistic regression analyses revealed that both low handgrip strength (OR = 2.19, 95% CI: 1.11–4.29) and high waist circumference (OR = 2.03, 95% CI: 1.03–3.99) were associated with MCI.

Conclusions

DAO, which can be easily diagnosed by a combination of handgrip strength and waist circumference, was associated with MCI in patents with cardiometabolic metabolic disease. This study suggests that screening for MCI in DAO patients could be important for early intervention of dementia prevention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02948-1.

Association among cognitive function, physical fitness, and health status in older women

This study examined the association among cognitive function, physical fitness, and health status in healthy older women. Ninety-four females aged from 62 to 86 years (72.66±5.38 years) from community healthcare centers and an exercise club in Seoul, South Korea. Cognitive function was assessed using the Seoul Neuropsychological Screening Battery. Physical performance comprised cardiorespiratory endurance, lower extremity strength, active balance ability, and walking speed. Health status included blood pressure and waist circumference. Multiple linear regression analyses were performed to determine the relationship among cognitive function, fitness components, and health status, with age and educational attainment as covariates. In the unadjusted model, attention was significantly associated with cardiovascular endurance (B=0.19, P<0.05). Memory was significantly associated with lower limb strength (B=0.77, P<0.05) and active balance ability (B=2.35, P<0.05). In the adjusted model, attention was significantly associated with cardiovascular endurance (B=0.15, P<0.05). Memory was significantly associated with lower limb strength (B=0.87, P<0.05). In both models, cognitive function was not significantly associated with any health status variable. Though limited by a relatively small sample of female participants, who were healthy registrants of a community exercise program with normal cognitive function, the current study demonstrates that cognitive function is significantly associated with physical fitness, but not with health status, in healthy older women.

Pathways linking abdominal obesity to poor memory function: Explore the mediating role of hypertension and depressive symptoms

BACKGROUND

The negative effect of abdominal obesity on cognitive function has been widely reported, especially on memory function, however, it is unclear how the effect is mediated. We aim to investigate the mediating role of hypertension and depressive symptoms.

METHODS

Data were collected from wave 6 (2012-2013) of the English Longitudinal Study of Ageing (ELSA). Abdominal obesity was defined as a waist circumference (WC) ≥88cm for women and ≥102cm for men. Hypertension was determined on the basis of objective blood pressure measurement and previous physician diagnosis. Depressive symptoms were assessed with the 8-item version of the Center for Epidemiologic Studies (CESD) scale. Memory function was measured with the 10-word immediate and delayed recall tests. Baron and Kenny's causal steps and Karlson/Holm/Breen (KHB) method were used to examine the mediating effect.

RESULTS

A total of 7,448 participants aged ≥50 years were included in this study. We found a negative effect of abdominal obesity on memory function (β=-0.047, p=0.031). KHB method identified significant mediating effect of hypertension and depressive symptoms on the relationship between abdominal obesity and memory function, they explained 16.92 and 6.32% of the total effect of abdominal obesity on memory function, respectively.

LIMITATIONS

This study was limited by its cross-sectional design and possibility of residual confounding.

CONCLUSIONS

Hypertension and depressive symptoms might be possible pathways linking abdominal obesity and poor memory function, suggesting that collaborative interventions of abdominal obesity, hypertension and depressive symptoms are beneficial in maintaining memory function.

The identification of established modifiable mid-life risk factors for cardiovascular disease which contribute to cognitive decline: Korean Longitudinal Study of Aging (KLoSA)

INTRODUCTION

We explored how different chronic diseases, risk factors, and protective factors highly associated with cardiovascular diseases (CVD) are associated with dementia or Mild Cognitive Impairment (MCI) in Korean elders, with a focus on those that manifest in mid-life.

METHODS

A CVD-free cohort (n = 4289) from the Korean Longitudinal Study of Aging was selected to perform Cox mixed-effects proportional hazard regressions. Eighteen control variables with strong associations to CVD were chosen as explanatory variables, and Mini-Mental State Examination (MMSE) score cut-off for dementia and MCI were used as outcome variables.

RESULTS

The statistically significant (P < 0.05) adverse factors that contribute in developing dementia were age (aHR 1.07, 1.05-1.09), Centre for Epidemiological Studies Depression Scale (CESD-10) (aHR 1.17, 1.12-1.23), diagnosis with cerebrovascular disease (aHR 3.73, 1.81-7.66), living with diabetes (aHR 2.30, 1.22-4.35), and living with high blood pressure (HBP) (aHR 2.05, 1.09-3.87). In contrast, the statistically significant protective factors against developing dementia were current alcohol consumption (aHR 0.67, 0.46-0.99), higher educational attainment (aHR 0.36, 0.26-0.56), and regular exercise (aHR 0.37, 0.26-0.51). The factors with a statistically significant adverse association with progression to MCI were age (aHR 1.02, 1.01-1.03) and CESD-10 (aHR 1.17, 1.14-1.19). In contrast, the statistically significant protective factors against developing MCI were BMI (aHR 0.96, 0.94-0.98), higher educational attainment (aHR 0.33, 0.26-0.43), and regular exercise (aHR 0.83, 0.74-0.92).

CONCLUSION

In lieu of the protective factor of MCI and dementia, implementing regular exercise routine well before mid-life and cognitive decline is significant, with adjustments made for those suffering from health conditions, so they can continue exercising despite their morbidity. Further attention in diabetes care and management is needed for patients who already show decline in cognitive ability as it is likely that their MCI impacts their ability to manage their existing chronic conditions, which may adversely affect their cognitive ability furthermore.

Relationship between Central Obesity and the incidence of Cognitive Impairment and Dementia from Cohort Studies Involving 5,060,687 Participants

Central obesity, measured by the waist circumference (WC) or waist-to-hip ratio, has been linked with metabolic dysfunction and structural abnormalities in the brain, two risk factors for cognitive impairment and dementia. The current analysis was performed to understand the influence of central obesity on the incidence of cognitive impairment and dementia. It included 21 studies involving 5,060,687 participants and showed that a high WC was associated with a greater risk of cognitive impairment and dementia (HR = 1.10, 95 % CI: 1.05-1.15), compared with a low WC. Sub-group analysis showed that a high WC increased the likelihood of developing cognitive impairment and dementia in individuals older than 65 years of age (HR = 1.13, 95 % CI: 1.08-1.19), whereas no association was observed in individuals younger than 65 years of age (HR = 1.04, 95 % CI: 0.93-1.16). Furthermore, dose-response meta-analysis confirmed that a high WC was a risk factor for cognitive impairment and dementia. In conclusion, central obesity, as measured by WC, was associated with a risk of cognitive impairment and dementia.

The effect of body fatness on regional brain imaging markers and cognitive function in healthy elderly mediated by impaired glucose metabolism

Brain atrophy is related to vascular risk factors and can increase cognitive dysfunction risk. This community-based, cross-sectional study investigated whether glucose metabolic disorders due to body fatness are linked to regional changes in brain structure and a decline in neuropsychological function in cognitively healthy older adults. From 2016 to 2019, 429 participants underwent measurements for cortical thickness and subcortical volume using 3 T magnetic resonance imaging and for cognitive function using the neuropsychological screening battery. The effects of body fatness mediated by impaired glucose metabolism on neuroimaging markers and cognitive function was investigated using partial least square structural equation modeling. Total grey matter volume (β = -0.020; bias-corrected (BC) 95% confidence interval (CI) = -0.047 to -0.006), frontal (β = -0.029; BC 95% CI = -0.063 to -0.005) and temporal (β = -0.022; BC 95% CI = -0.051 to -0.004) lobe cortical thickness, and hippocampal volume (β = -0.029; BC 95% CI = -0.058 to -0.008) were indirectly related to body fatness. Further, frontal/temporal lobe thinning was associated with recognition memory (β = -0.005; BC 95% CI = -0.012 to -0.001/β = -0.005; BC 95% CI = -0.013 to -0.001) and delayed recall for visual information (β = -0.005; BC 95% CI = -0.013 to -0.001/β = -0.005; BC 95% CI = -0.013 to -0.001). Additionally, the smaller the hippocampal volume, the lower the score in recognition memory (β = -0.005; BC 95% CI = -0.012 to -0.001), delayed recall for visual information (β = -0.005; BC 95% CI = -0.012 to -0.001), and verbal learning (β = -0.008; BC 95% CI = -0.017 to -0.002). Our findings indicate that impaired glucose metabolism caused by excess body fatness affects memory decline as well as regional grey matter atrophy in elderly individuals with no neurological disease.

Proposed cut-off points for anthropometric and bioelectrical measures based on overweight and obesity criteria in Spanish institutionalised elderly people

The increasing prevalence of obesity among the institutionalised elderly population and its severe consequences on health requires an early and accurate diagnosis that can be easily achieved in any clinical setting. This study aimed to determine new cut-off values for anthropometric and bioelectrical impedance measures that are superior to body mass index criteria for overweight and obesity status in a sample of Spanish institutionalised elderly population. A total of 211 institutionalised older adults (132 women, aged 84.3±7.3 years; 79 men, aged 81.5±7.3 years) were enrolled in the current cross-sectional study. Anthropometric and bioelectrical impedance measures included the body mass index, waist circumference, gluteal circumference, waist-hip ratio, sagittal-abdominal diameter, trunk fat, and visceral-fat ratio. In women, the waist circumference, gluteal circumference, sagittal-abdominal diameter, trunk fat, and visceral-fat index presented strongly significant specificity and sensitivity (area under the curve [AUC], p<0.0001) and elevated discriminative values (receiver operating characteristic [ROC] curves: 0.827 to 0.867) for overweight and obesity status. In men, the waist-hip ratio, waist circumference, gluteal circumference, sagittal-abdominal diameter, trunk fat, and visceral-fat ratio were strongly significant AUC (p<0.0001), with moderate-to-high values (ROC curves: 0.757-0.871). In conclusion, our findings suggest that gluteal circumference, waist circumference, and sagittal-abdominal diameter in women and trunk fat, visceral-fat ratio, and waist circumference in men may represent more suitable cut-off values superior to body mass index criteria for overweight and obesity in the Spanish institutionalised elderly population.

Association Between Gamma-Glutamyl Transferase and Mild Cognitive Impairment in Chinese Women

Background: Dementia, as a global public health problem, is becoming increasingly serious. As a precursor of dementia, mild cognitive impairment (MCI) plays an important role in the diagnosis and prevention of dementia. Recent studies have found a correlation between gamma-glutamyl transferase (GGT) levels and cognitive function in men. The relationship between GGT levels and cognitive function in women remains unclear because GGT activity and expression differ between the sexes. Method: We recruited a total of 2,943 Chinese women from Jidong and Taian in 2019. We grouped the participants according to GGT levels, diagnosed MCI using the Montreal Cognitive Assessment (MOCA) scale, and modeled the study outcomes using logistic regression to explore the relationship between GGT level and MCI. We also analyzed the interaction of obesity, sleep duration, and hyperuricemia with GGT in the development of MCI. Results: The prevalence of MCI increased with increasing GGT level, from the lowest quartile to the highest quartile of GGT: 8.4% (66/786), 14.2% (119/840), 17.6% (108/613), and 21.4% (151/704), respectively. At the same time, as GGT levels increased, so did the risk of MCI. In the fully adjusted model, compared with those for participants in the lowest GGT quartiles, the odds ratios (ORs), and 95% confidence intervals (CIs) for MCI for participants in the second, third, and fourth GGT quartiles were 1.49 (1.04-2.12), 1.53(1.06-2.21), and 1.88 (1.33-2.65), respectively. The risk of developing MCI was further increased in people with high GGT levels who were obese (OR = 1.96, 95% CI: 1.39-2.76, P < 0.001), slept less (OR = 1.91, 95% CI: 1.35-2.71, P < 0.001), had high levels of uric acid (OR = 1.55, 95% CI: 1.03-2.32, P < 0.001), or after menopause (OR = 2.92, 95% CI: 2.07-4.12, P < 0.001). Conclusion: We found that MCI is more common in women with elevated GGT levels, so GGT could be a potential diagnostic marker for MCI. Meanwhile, our findings indicated that women with high GGT levels had an increased risk of MCI when they were obese, sleep deprived, had high serum uric acid (SUA) levels or underwent menopause.

Associations of BMI and Serum Urate with Developing Dementia: A Prospective Cohort Study

CONTEXT

Recent studies have suggested that a higher body mass index (BMI) and serum urate levels were associated with a lower risk of developing dementia. However, these reverse relationships remain controversial, and whether serum urate and BMI confound each other is not well established.

OBJECTIVES

To investigate the independent associations of BMI and urate, as well as their interaction with the risk of developing dementia.

DESIGN AND SETTINGS

We analyzed a cohort of 502 528 individuals derived from the UK Biobank that included people aged 37-73 years for whom BMI and urate were recorded between 2006 and 2010. Dementia was ascertained at follow-up using electronic health records.

RESULTS

During a median of 8.1 years of follow-up, a total of 2138 participants developed dementia. People who were underweight had an increased risk of dementia (hazard ratio [HR] = 1.91, 95% confidence interval [CI]: 1.24-2.97) compared with people of a healthy weight. However, the risk of dementia continued to fall as weight increased, as those who were overweight and obese were 19% (HR = 0.81, 95%: 0.73-0.90) and 22% (HR = 0.78, 95% CI: 0.68-0.88) were less likely to develop dementia than people of a healthy weight. People in the highest quintile of urate were also associated with a 25% (HR = 0.75, 95% CI: 0.64-0.87) reduction in the risk of developing dementia compared with those who were in the lowest quintile. There was a significant multiplicative interaction between BMI and urate in relation to dementia (P for interaction = 0.004), and obesity strengthens the protective effect of serum urate on the risk of dementia.

CONCLUSION

Both BMI and urate are independent predictors of dementia, and there are inverse monotonic and dose-response associations of BMI and urate with dementia.

Higher risk of dementia in English older individuals who are overweight or obese

BACKGROUND

Several risk factors contribute to dementia, but the role of obesity remains unclear. This study investigated whether increased body weight or central obesity were associated with a higher risk of developing dementia in a representative sample of older English adults.

METHODS

We studied 6582 participants from the English Longitudinal Study of Ageing (ELSA) who were aged ≥50 years and were dementia-free at baseline, that being either wave 1 (2002-2003) for study members who started at wave 1, or at either wave 2 (2004-2005) or 4 (2008-2009) for those who began the study as refreshment samples. Body mass index (BMI) was measured at baseline and categorized into normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2) and obese (≥30 kg/m2). Central obesity was defined as a waist circumference (WC) >88 cm for women and >102 cm for men. Cumulative incidence of dementia was ascertained based on physician-diagnosed dementia, an overall score >3.38 on the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) and Hospital Episodes Statistics (HES) data at every ELSA wave from baseline until wave 8 (2016-2017). Cox proportional hazards models were used to assess the association between baseline BMI levels or abdominal obesity in relation to dementia incidence during the mean follow-up period of 11 years.

RESULTS

From the overall sample, 6.9% (n = 453) of participants developed dementia during the follow-up period of maximum 15 years (2002-2017). Compared with participants with normal weight, those who were obese at baseline had an elevated risk of dementia incidence [hazard ratio (HR) = 1.34, 95% confidence interval (CI) 1.07-1.61] independent of sex, baseline age, apolipoprotein E-ε4 (APOE-ε4), education, physical activity, smoking and marital status. The relationship was slightly accentuated after additionally controlling for hypertension and diabetes (HR = 1.31, 95% CI 1.03-1.59). Women with central obesity had a 39% greater risk of dementia compared with non-central obese women (HR = 1.39, 95% CI 1.12-1.66). When compared with a normal BMI and WC group, the obese and high WC group had 28% (HR = 1.28, 95% CI 1.03-1.53) higher risk of dementia.

CONCLUSIONS

Our results suggest that having an increased body weight or abdominal obesity are associated with increased dementia incidence. These findings have significant implications for dementia prevention and overall public health.