Association of waist-calf circumference ratio with incident cognitive impairment in older adults

Adiposity and dementia among Chinese adults: longitudinal study in the China Health and Retirement Longitudinal Study (CHARLS)

BACKGROUND

Evidence on the age-dependent association between adiposity and risk of dementia in the Chinese population is unclear. We aim to disentangle the association of mid- and late- life adiposity with subsequent dementia risk in Chinese adults and compare ageing trajectories of adiposity between those with/out dementia.

METHODS

Dementia was ascertained based on cognitive batteries and the Activity of Daily Living Scale in the China Health and Retirement Longitudinal Study (CHARLS). Adiposity was measured by body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WtHR). We estimated hazard ratio (HR) of adiposity for incident dementia by age groups (i.e. 50-64, and ≥65). Age trajectories of adiposity measures were fitted using a mixed-effect model in a case-control design. The interaction terms of age and dementia were included to examine the difference between cases and controls.

RESULTS

Hazard ratios (HRs) for incident dementia in two age groups (50-64 and ≥65) were estimated in 13,355 participants. Raised mid-life BMI was associated with incident dementia (HR (95% CI): overweight 1.33 (1.03 to 1.73), obesity 1.63 (1.17 to 2.28)). Mid-life abdominal obesity was associated with incident dementia (WC 1.45 (1.15 to 1.84), WtHR 1.44 (1.08 to 1.94)), accounting for ≤24.2% of dementia cases. Among participants developing dementia, adiposity measures were higher in mid-life and declined faster with age, compared to those remaining dementia-free. Late-life adiposity was not associated with dementia risk.

CONCLUSION

Mid-life but not late-life adiposity was associated with dementia incidence in China. Accelerated weight loss in prodromal dementia is likely to explain the mixed evidence on adiposity and dementia risk in the Chinese population. Rapid decline in adiposity in later life may be an early sign. Reducing mid-life adiposity in the population may mitigate the future dementia burden.

Exploring geriatric syndromes among physically disabled older adults: A network analysis

OBJECTIVE

To explore the network structure of common geriatric syndromes and conditions in physically disabled older adults.

METHODS

We chose fourteen common geriatric syndromes and conditions from the dataset and estimated networks with the partial correlation network method. We tested the stability and accuracy of the network using the package "bootnet" in R software.

RESULTS

The common geriatric syndromes and conditions were positively connected within the network, and strong connections emerged between chronic pain and dyspnea, and urinary incontinence and vision impairment. Polypharmacy, chronic pain, cognitive impairment and urinary incontinence were strongly and directly connected with the network.

CONCLUSION

Healthcare professionals, caregivers, and older adults should pay more attention to the occurrence and development of these four syndromes as well as the interactions between the different syndromes during intervention planning. Interventions targeting multiple geriatric syndromes or a factor common to various syndromes may be more feasible and more effective.

Associations of dynapenic abdominal obesity and its components with cognitive impairment among hemodialysis patients

OBJECTIVE

Cognitive impairment (CI) is a prevalent and significant health concern among patients undergoing maintenance hemodialysis (MHD). Recent studies have highlighted the growing interest in dynapenic abdominal obesity (DAO), which combines both low muscle strength and excess abdominal fat. Despite the increasing recognition of DAO, its association with CI in MHD patients remains uncertain. The objective of this study was to investigate the relationship between DAO and CI in MHD patients.

METHODS

We conducted a multicenter, cross-sectional study in twenty dialysis centers, encompassing 3767 adult MHD patients. Participants were categorized into four distinct groups based on the criteria for abdominal obesity (AO), defined as waist circumference (WC) ≥ 90 cm for men and ≥ 85 cm for women, and dynapenia, characterized by handgrip strength (HGS) < 28 kg in men and < 18 kg in women. The groups were: non-dynapenic/non-abdominal obesity (NDNAO), non-dynapenic/abdominal obesity (NDAO), dynapenic/non-abdominal obesity (DNAO), and dynapenic/abdominal obesity (DAO). Cognitive function was assessed using the Mini-Mental State Examination (MMSE), with a score below 27 indicating cognitive impairment (CI). Multivariate logistic models were used to investigate the correlations between DAO and its components with the risk of CI. Smooth curve fittings were used to identify the potential nonlinear relationship between WC and the MMSE scores. The piecewise regression model was used for fitting while the log-likelihood ratio test was used to determine whether a significant inflection point existed. Additionally, we conducted a series of subgroup analyses to test the robustness of our results.

RESULTS

The multi-variable adjusted odds ratios (ORs) of CI for DNAO and DAO were 2.10 (1.68-2.62, P < 0.001) and 1.81 (1.40-2.33, P < 0.001), respectively. These findings were consistently observed across subgroup analyses, indicating robustness in our results. AO was associated with increased risk of CI in the crude model (OR 1.22, 95%CI 1.05-1.41; P = 0.008), however, it became a protective factor after adjusting for potential confounders (OR 0.84, 95%CI 0.71-0.98; P = 0.03). We identified a significant nonlinear relationship between WC, HGS, and MMSE scores (P for non-linearity < 0.05). Notably, an inflection point at 23.29 kg for HGS was determined through threshold effect analysis. Below a WC threshold of 101 cm, MMSE scores demonstrated a positive correlation with WC (β = 0.03, 95% CI 0.01-0.04, P < 0.001). However, this relationship did not achieve statistical significance for WC values above 101 cm.

CONCLUSIONS

Both DAO and DNAO are associated with increased odds of CI in MHD patients, with dynapenia being the major factor contributing to the increased odds of CI, while AO appears to play a protective role against CI.

Association of calf circumference with osteoporosis and hip fracture in middle-aged and older adults: a secondary analysis

BACKGROUND

Osteosarcopenia is a geriatric syndrome associated with an increased risk of frailty, falls, fractures, disability, and death. Calf circumference (CC) has been used as a simple and practical skeletal muscle marker to diagnose sarcopenia. This study aimed to explore the relationship of calf circumference and osteoporosis (OP) and hip fractures (HF) in middle-aged and older adults. This is important for screening OP and HF in the community and improving the quality of life of older adults.

METHODS

This study was based on the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Logistic regression analysis and restricted cubic spline were used to investigate the correlation of CC with OP and HF. The receiver operating characteristic (ROC) curve was utilized to determine the optimal cut-off value for CC. Finally, logistic regression model analysis was applied to test the predictive efficacy of CC.

RESULTS

Among 4575 individuals with a mean age of 63.0 ± 11.5 years, the OP group had higher proportions of females (P < 0.001) and non-Hispanic whites (P < 0.001). Logistic regression and RCS demonstrated that lower CC was associated with a greater risk of OP and HF in the female group (P < 0.001). ROC curves showed that CC of 33.65 cm and 33.85 cm were the best cut-off values for predicting OP and HF in middle-aged and older females. Logistic regression analyses found good predictive efficacy for cut-off values of CC in females.

CONCLUSION

In middle-aged and older women, low CC is associated with a higher risk of OP and HF. These findings have important implications for managing osteosarcopenia and associated fractures in older adults.

CLINICAL TRIAL NUMBER

Not applicable.

The association between waist-to-height ratio and cognitive function in older adults

OBJECTIVES

The waist-to-height ratio (WHtR) is a simple, practical, and effective tool used to assess central obesity. Despite its usefulness, few studies have investigated the association between WHtR and cognitive function among older adults in the United States. This study aims to investigate the associations between WHtR and cognitive function.

METHODS

The study sample comprised adults who participated in the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014. WHtR was calculated from measured waist circumference and height. Cognitive function was assessed using the digit symbol substitution test. A weighted multiple linear regression analysis was performed to evaluate the association between WHtR and cognitive function, with smooth curve fitting applied to detect non-linearities.

RESULTS

Our analysis included 1709 participants over the age of 65. After adjusting for potential confounders, WHtR was found to have a negative association with cognitive function (β = -36.91, 95% CI: -54.54 to -19.29, P < 0.001). Subgroup analyzes stratified by sex and race showed that the negative correlation of WHtR with cognitive function remained in both men and women, as well as in non-Hispanic white and other races. Among women, the association between WHtR and cognitive function followed an inverted U-shaped curve, with an inflection point of 0.68.

CONCLUSION

This study provides evidence of a negative association between WHtR and cognitive function in older adults. These findings suggest that in advanced age, central obesity may have negative implications for cognitive function.

Waist-to-calf circumference ratio as a potential indicator of diabetes risk: results from the Longevity Check-Up (Lookup) 8

Diabetes is a prevalent metabolic condition with substantial health and economic impacts. Therefore, effective and accessible indicators are essential for early detection and prevention. This study investigates the link between the waist-to-calf circumference ratio (WCR) and diabetes risk in a large cohort from the Longevity Check-Up (Lookup) 8+ Study. The present investigation is a retrospective cross-sectional study. Diabetes was defined either as self-reported diagnosis, or fasting plasma glucose equal to or greater than 126 mg/dL, or random plasma glucose equal to or greater than 200 mg/dL. The WCR was calculated by dividing waist circumference by calf circumference. A total population of 8900 participants (mean age 57.1 ± 14.8 years, 55% women) was included in the study. The prevalence of diabetes was 9.4%. Mean WCR displayed a significant trend (p for trend < 0.001), and the analysis of covariance (ANCOVA) revealed significant differences among the normal, pre-diabetes, diabetes groups. Unadjusted logistic regression showed a positive association between higher WCR and diabetes, which remained significant in the adjusted models. Receiver operating characteristic curve analysis indicated that WCR had a higher area under the curve compared to waist circumference alone, with cut-off values of 2.35 for men and 2.12 for women providing high sensitivity (91% for men, 92% for women) and specificity (74% for men, 75% for women). Our study introduces WCR as a novel, simple, and cost-effective anthropometric measure for identifying individuals at risk of diabetes, suitable for clinical use, especially in resource-limited settings.

Dynapenic abdominal obesity and the risk of depressive symptoms in middle-aged and older Chinese adults: Evidence from a national cohort study

BACKGROUND

Population-based evidence on the relationship between dynapenic abdominal obesity and depressive symptoms is rare. We aimed to prospectively investigate the relationship between dynapenic abdominal obesity and depressive symptoms among middle-aged and older Chinese adults.

METHODS

A total of 9322 participants free of depressive symptoms in the China Health and Retirement Longitudinal Study were included. The participants were divided into four groups: non-dynapenic/non-abdominal obesity (ND/NAO), non-dynapenic/abdominal obesity (ND/AO), dynapenic/non-abdominal obesity (D/NAO) and dynapenic/abdominal obesity (D/AO) according to the sex-specific grip strength (<28 kg for men and <18 kg for women) and waist circumference (≥85 cm for men and ≥80 cm for women) that in line with the Chinese criteria. Depressive symptoms was defined as a score of ≥12 for the 10-item Center for Epidemiological Studies Depression Scale. Logistic regression model was used to explore the association between dynapenic abdominal obesity and depressive symptoms.

RESULTS

After an approximately 3-year of follow-up, 1810 participants (19.4 %) developed depressive symptoms. The multivariable-adjusted odds ratio for the D/AO versus ND/NAO was 1.61 (95 % CI: 1.31-1.98) for depressive symptoms. In addition, this relationship was more profound in participants aged<60 years (OR = 2.27, 95 % CI: 1.60-3.22) than participants aged ≥60 (OR = 1.36, 95 % CI: 1.05-1.77; P-interaction = 0.04). However, dynapenic obesity (defined by body mass index) was not linked to depressive symptoms.

LIMITATIONS

Causal link and residual confounding were not addressed because of the observational study design.

CONCLUSIONS

Dynapenic abdominal obesity was associated with an increased risk of depressive symptoms, especially among those aged<60 years.

Effect of dietary supplementation with multinutrient soy flour on body composition and cognitive function in elderly individuals at the risk of low protein: a randomized, double-blind, placebo-controlled study

Insufficient protein intake and cognitive decline are common in older adults; however, there have been few studies on low protein risk screening and complex nutrient interventions for elderly individuals in rural communities. This study aimed to evaluate the effect of dietary multinutrient soy flour (MNSF) on body composition and cognitive function in elderly individuals who are at risk of protein deficiency in a randomized, double-blind, placebo-controlled clinical trial. Nutritional interventions were given to those found to have low protein levels using bioelectrical impedance analysis (BIA). Among 733 older adults screened, 62 participants were included and randomly assigned into two groups, one taking soy flour and the other taking MNSF for 12 weeks. A previous cross-sectional survey found that 35.1% of the elderly people with an average age of 71.61 ± 5.94 years had an inadequate body protein mass proportion. After the intervention, the MNSF group demonstrated a significant improvement in protein mass, muscle mass, mineral levels, skeletal muscle mass, and fat-free mass compared with baseline (all P < 0.05), as well as a better upward trend compared with the soy flour group (P = 0.08; P = 0.07; P = 0.05; P = 0.08; P = 0.07). Regarding the mini-mental state examination (MMSE) scores, the MNSF group showed a significant decrease after 12 weeks (P < 0.05), which were significantly different compared with the soy flour group (P < 0.05). In the future, the application of MNSF as a food-based supplement to improve nutrition and delay cognitive decline in older adults at the risk of protein deficiency may be considered.

Association of waist-calf circumference ratio, waist circumference, calf circumference, and body mass index with all-cause and cause-specific mortality in older adults: a cohort study

BACKGROUND

Waist circumference (WC), calf circumference (CC), and body mass index (BMI) have been independently linked to mortality. However, it's not yet clear how the waist-calf circumference ratio (WCR) relates to mortality. This study aims to investigate the relationship between WCR, WC, CC, and BMI with all-cause and cause-specific mortality in older adults.

METHODS

In the 2014 Chinese Longitudinal Healthy Longevity Survey, 4627 participants aged 65 years and older were included, and they were subsequently followed up in 2018. Cox proportional hazards models were utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality, based on WCR, WC, CC, and BMI.

RESULTS

During a median follow-up of 3.4 years, 1671 deaths (36.1%) occurred. Compared to the second quartile of WCR, the highest quartile had a higher risk of mortality from all causes (HR 1.42, 95%CI 1.24-1.64), cardiovascular disease (CVD) (HR 1.88, 95%CI 1.38-2.56), and other causes (HR 1.37, 95%CI 1.15-1.63). The first and fourth quartiles of WC had HRs of 2.19 (1.00-4.79) and 2.69 (1.23-5.89), respectively, for cancer mortality. The highest quartile of CC was associated with a lower risk of all-cause and other-cause mortality, whereas the lowest quartile was associated with a higher risk of all-cause, CVD, and other-cause mortality compared to the second CC quartile. Additionally, the lowest quartile of BMI was associated with a higher risk of all-cause and respiratory disease mortality. Interaction analyses showed that the effects of CC on all-cause and CVD mortality were more pronounced in adults aged ≥ 80 years (P-interaction < .05).

CONCLUSIONS

Higher WCR and lower CC increased the risk of all-cause, CVD, and other-cause mortality. Lower BMI was associated with higher all-cause and respiratory disease mortality risk, while WC only predicted cancer mortality.

Is waist-calf circumference ratio associated with frailty in older adults? Findings from a cohort study

BACKGROUND

The waist-calf circumference ratio (WCR) has been suggested as a potential indicator of visceral adiposity. Nevertheless, the relationship between WCR and the risk of frailty remains unclear. Therefore, our study aimed to investigate the association between WCR and longitudinal changes in WCR with frailty risk in older adults.

METHODS

We included 2359 participants aged ≥ 65 years without frailty (frailty index [FI] ≤ 0.21) from the Chinese Longitudinal Healthy Longevity Survey in the 2014 wave. The follow-up was conducted in 2018. We investigated the relationship of WCR, waist circumference (WC), and calf circumference (CC) with frailty using both the Cox proportional hazards model and the generalized estimating equation (GEE).

RESULTS

During a median follow-up of 4.0 years, 668 (28.2%) frailty occurred. Those with higher WCR and WC had a significantly increased risk of frailty (fifth quintile compared with first quintile: hazard ratio [HR] = 1.59, 95% confidence interval [CI] 1.24-2.04 for WCR; HR = 1.69, 95% CI 1.27-2.24 for WC), whereas those in the fourth quintile of CC had a lower likelihood of developing frailty compared to those in the first quintile (HR = 0.67, 95% CI 0.50-0.89). Interaction analyses showed that the effects of WCR on frailty were more pronounced in females (P-interaction = 0.016). GEE analyses revealed that increased WCR and WC were associated with a higher risk of frailty (odds ratio [OR] = 1.74, 95% CI 1.43-2.12 for WCR; OR = 1.03, 95% CI 1.02-1.04 for WC), while CC showed opposite results (OR = 0.95, 95% CI 0.93-0.97).

CONCLUSIONS

A higher WCR and WC, as well as a lower CC, were significantly associated with higher frailty. Of these measures, WCR demonstrated the strongest association with frailty, suggesting that having a combination of high central fat and low lean body mass may increase the risk of developing frailty.

Waist-to-calf circumstance ratio and cognitive function among Chinese older adults: Mediating roles of physical performance and social activity

Background

In light of the potentially detrimental effects of central fat and decreased muscle mass on cognitive function, it would be beneficial to learn more about the mediating mechanisms underpinning the association between the two. The purpose of this study is to determine the association between waist-to-calf circumstance ratio (WCR) and cognitive function, as well as to investigate whether physical performance and social activity mediate the relationship between WCR and cognitive function among older Chinese adults.

Methods

An analysis of 9,652 older Chinese adults was conducted during the 2018 wave of the Chinese Longitudinal Health Longevity Survey (CLHLS). The Mini-Mental State Examination (MMSE) and a self-reported scale were used to measure cognitive function, physical performance, and social activity, respectively. Multiple linear regression and mediation analyses were conducted.

Results

The findings suggest that a high WCR had a significant negative association with cognitive function (B = -0.535, 95% CI: -0.754, -0.317). Mediation analysis revealed that a high WCR influenced old adults' cognitive function in three ways: first, through the partial mediating effect of physical performance (B = -0.270; 95% CI: -0.340, -0.203); second, through the partial mediating effect of social activity (B = -0.035; 95% CI: -0.055, -0.017); and third, through the serial mediating effects of physical performance and social activity (B = -0.021, 95% CI: -0.029, -0.015).

Conclusion

The study results suggest the adverse impact of a high WCR on older adults' cognitive function, and the possible mechanisms of physical performance and social activity by which the association takes place. Multidimensional health and social interventions aimed at improving physical, social, and cognitive functioning among older adults with sarcopenic obesity are recommended.

Adherence to High Dietary Diversity and Incident Cognitive Impairment for the Oldest-Old: A Community-Based, Nationwide Cohort Study

BACKGROUND AND AIMS

Dietary diversity change is associated with cognitive function, however, whether the effect still exists among the oldest-old (80+) is unclear. Our aim was to examine the effect of dietary diversity changes on cognitive impairment for the oldest-old in a large prospective cohort.

METHODS

Within the Chinese Longitudinal Healthy Longevity Study, 6237 adults older than 80 years were included. The dietary diversity score (DDS) was assessed by a simplified food frequency questionnaire (FFQ). Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score lower than 18 points. Cognitive decline was defined as a reduction of total MMSE score ≥3 points, and cognitive decline of different subdomains was defined as a reduction of ≥15% in the corresponding cognitive domain. The multivariate-adjusted Cox proportional hazard model evaluated the effects of DDS change on cognitive decline. The linear mixed-effect model was used to test subsequent changes in MMSE over the years.

RESULTS

During 32,813 person-years of follow-up, 1829 participants developed cognitive impairment. Relative to the high-high DDS change pattern, participants in the low-low and high-low patterns were associated with an increased risk of cognitive impairment with a hazard ratio (95% confidential interval, CI) of 1.43 (1.25, 1.63) and 1.44 (1.24, 1.67), and a faster decline in the MMSE score over the follow-up year. Participants with the low-high pattern had a similar incidence of cognitive impairment with HRs (95% CI) of 1.03 (0.88, 1.20). Compared with the stable DDS status group (-1-1), the risk of cognitive impairment was higher for those with large declines in DDS (≤-5) and the HR was 1.70 (95% CI: 1.44, 2.01).

CONCLUSIONS

Even for people older than 80, dietary diversity change is a simple method to identify those who had a high risk of cognitive decline. Keeping high dietary diversity is beneficial for cognitive function and its subdomain even in the final phase of life, especially for females and the illiterate oldest-old.

Systolic Blood Pressure and Mortality in Community-Dwelling Older Adults: The Role of Frailty

OBJECTIVES

To investigate whether frailty modifies the association of systolic blood pressure (SBP) with cardiovascular mortality and all-cause mortality in community-dwelling older adults.

DESIGN

A prospective cohort study.

SETTING

A population-based study of nationally representative older Chinese adults in a community setting.

PARTICIPANTS

This study included participants aged 65 years or older from the Chinese Longitudinal Healthy Longevity Survey 2002-2014 and followed up to 2018.

MEASUREMENTS

Participants were divided into two groups according to a frailty index based on the accumulation of a 44-items deficits model. The association between SBP and mortality was analyzed using multivariable-adjusted Cox proportional hazards models.

RESULTS

Among 18,503 participants included, the mean age was 87.2 years and the overall median follow-up time was 42.7 months. We identified 7808 (42.2%) frail participants (mean frailty index=0.33), in which 7533 (96.5%) died during the follow-up. Effect modification by frailty was detected (P for interaction=0.032). Among frail participants, a U-shaped association was found with hazard ratios of 1.16 (95% CI, 1.02-1.32) for SBP < 100 mmHg, and 1.11 (95% CI, 1.00-1.24) for SBP ≥ 150 mmHg compared with SBP 120-130 mmHg. For non-frail older adults, a tendency toward higher risk among those with SBP ≥ 130 mmHg was observed. The analyses towards cardiovascular mortality showed similar results.

CONCLUSION

Our results suggest the presence of effect modification by frailty indicating a possible negative effect for elevated SBP in non-frail older adults and a U-shaped relationship of SBP in frail older adults with respect to mortality even after adjusting for diastolic blood pressure.