Associations of Dynapenic Abdominal Obesity and Frailty Progression: Evidence from Two Nationwide Cohorts

Anemia as a mediator: bridging the frailty index and hip fractures in older Chinese populations

Background

Hip fracture is a significant global public health issue. The link and mechanisms between frailty index (FI) and hip fracture remain unclear. This research examined how anemia mediates the link between FI and hip fracture.

Methods

The study analyzed data from the 2015 China Health and Retirement Longitudinal Study (CHARLS), which included 6,326 participants aged 60 and above. The mediating role of anemia in the relationship between FI and hip fracture was examined using bootstrap analysis and linear regression models.

Results

After controlling for confounding variables, FI was positively associated with hip fracture (OR = 1.13, 95% CI: 1.09-1.16; p < 0.001). Anemia was also positively associated with hip fracture (OR = 1.88, 95% CI: 1.33-2.64; p < 0.001). Mediation analysis showed that anemia indirectly affected the relationship between FI and hip fracture, accounting for 18.95% of the total effect. Subgroup analysis showed that compared with non-frail and non-anemic participants, frail and anemic participants had a significantly increased risk of hip fracture (OR = 4.61, 95% CI: 2.80-7.61). However, no interaction between frailty and anemia was observed for hip fracture risk.

Conclusions

The findings suggest that FI and anemia were positively associated with hip fracture, and anemia played a mediating role in the association between FI and hip fracture. Intervention based on exercise, nutrition and medical management can combat anemia and reduce FI and may be an effective way to prevent or delay hip fractures.

Association between abdominal obesity and cognitive decline among Chinese middle-aged and older adults: a 10-year follow-up from CHARLS

Introduction

The relationship between abdominal obesity and cognitive decline has controversial results, and the mediating effect of high-density lipoprotein cholesterol (HDL-C) between them remains uncertain. This study aims to explore the association between abdominal obesity and cognitive decline in middle-aged and older adults, including dose-response relationship and age differences, as well as the mediating effect of HDL-C.

Methods

Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS), involving 3,807 participants aged 45 and above from 2010 to 2020. The TICS-10 was used to assess cognitive function, and the group-based trajectory model (GBTM) was used to explore the potential heterogeneity of cognitive changes. Abdominal obesity was measured by baseline waist circumference (WC) and a sequentially adjusted unordered multinomial logistic regression was used to investigate the association between abdominal obesity and cognitive decline in middle-aged and older adults. Restricted cubic spline (RCS) model was adopted to analyze the dose-response relationship between WC and risk of cognitive decline. HDL-C was used as a mediator to examine the potential causal chain between abdominal obesity and cognitive decline.

Results

Among the 3,807 participants, a total of 1,631 individuals (42.84%) had abdominal obesity. The GBTM identified 3 cognitive function trajectories: rapid decline (11.0%), slow decline (41.1%) and stable groups (47.9%). After controlling for confounders, participants with abdominal obesity were less likely to experience rapid decline (OR: 0.67, 95%CI: 0.51-0.8) and slow decline (OR: 0.81, 95%CI: 0.69-0.95) of cognitive function, compared to those with normal WC. RCS analysis showed a decreased risk of cognitive decline with increasing WC. In the age subgroup analysis, the protective effect was significant only in the population aged 50 and above. HDL-C mediated 19.15% (P < 0.05) of the relationship between abdominal obesity and cognitive decline.

Conclusion

Abdominal obesity had a significant protective effect on cognitive decline in Chinese middle-aged and older adults, with HDL-C playing a mediating role in the relationship between abdominal obesity and cognitive decline.

Associations of insulin resistance estimated by glucose disposal rate with frailty progression

OBJECTIVES

To investigate the relationship between estimated glucose disposal rates (eGDR) and the progression of frailty, using longitudinal data.

METHODS

We analyzed four waves of data from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2018, involving 6,778 middle-aged and older adults. eGDR was calculated using a specific formula, categorizing participants into high and low eGDR groups based on the lowest quartile (8.5). Frailty status was assessed using the frailty index (FI). Linear mixed-effects models were employed to analyze the association between eGDR and frailty progression, as well as the impact of transitions in eGDR.

RESULTS

We found that the baseline FI was significantly higher in the low eGDR group compared to the high eGDR group. Furthermore, participants in the low eGDR group exhibited a faster progression of frailty, compared to those in the high eGDR group. Among non-frail participants at baseline, the association between low eGDR and accelerated frailty progression was even more pronounced. Further analysis revealed that, compared to participants who maintained a stable high eGDR, those who transitioned from high to low eGDR and those who consistently remained in the low eGDR group both experienced significantly accelerated frailty progression. On the contrary, participants who transitioned from low to high eGDR did not show a significant acceleration in frailty progression compared to those who consistently maintained a high eGDR.

CONCLUSION

Low eGDR is linked to accelerated frailty progression in middle-aged and older Chinese adults. Transitioning from low to high eGDR may mitigate this progression, highlighting the importance of eGDR in frailty management.

Longitudinal Cohort Study Investigating Fall Risk Across Diverse Muscle Health Statuses Among Older People in the Community

BACKGROUND

Falls constitute a significant public health concern among older adults, particularly those with diminished muscle health integrity. The relative contributions of reduced muscle mass versus impaired muscle function to fall risk remain debated. Discrepant conclusions in previous studies exist due to divergent muscle health categorizations and parameter measurements. This study investigated longitudinal risk of falls across a spectrum of muscle health statuses among older people in the community.

METHODS

Community-dwelling participants aged 65 years and older, undergoing annual health assessments, were enrolled between 2015 and 2023. Measurements included handgrip strength, walking speed and appendicular skeletal muscle mass. Dynapenia was defined as impaired muscle function with preserved muscle mass, presarcopenia was characterized as reduced muscle mass with maintained muscle function, and sarcopenia was identified as concurrent losses in both muscle mass and muscle function. Older people with normal muscle mass and muscle function were defined as having a robust muscle health status. Participants without a history of falls at baseline were monitored continuously and were censored if a fall incident was recorded during later yearly assessment. Kaplan-Meier and Cox regression analyses were used to compare fall risk across different muscle health statuses.

RESULTS

The final analysis included a total of 863 participants with a mean age of 71.93 ± 6.62 years, and 57.58% were female. Compared with the other groups, the dynapenic group exhibited a lower physical activity, greater body mass index and slower gait speed. The participants with dynapenia experienced the highest fall incidence (27.15%). The hazard ratios (HRs) for fall were 2.65 (95% confidence interval [CI] = 1.72-4.08, p < 0.001) for dynapenia, 1.54 (95% CI = 0.92-2.57, p = 0.095) for presarcopenia and 1.87 (95% CI = 1.04-3.33, p = 0.034) for sarcopenia. After adjustment for multiple covariates, the fall risk remained significantly greater in the dynapenic group (HR = 2.10, 95% CI = 1.28-3.43, p = 0.003) than in the sarcopenic group (HR = 1.31, 95% CI = 0.69-2.46, p = 0.402). Female dynapenic participants with coronary artery disease, arthritis and sedative agent use had a high fall risk, especially those with two or more risk factors (HR = 2.82, 95%CI = 1.37-5.82, p = 0.005).

CONCLUSIONS

Older adults with dynapenia exhibited a greater fall risk than did those with sarcopenia. Dynapenic older people with two or more risk factors, such as female sex, coronary artery disease, arthritis and sedative agent use, may have an increased longitudinal fall risk. Promoting muscle function should be prioritized as a preventive strategy to mitigate adverse clinical outcomes.

Association of visceral adiposity index and lipid accumulation product with frailty in U.S. adults: a cross-sectional study from NHANES

BACKGROUND

Frailty poses a considerable public health challenge because of its association with negative health consequences. Although obesity is recognized as a contributor to frailty, conventional measures fail to adequately account for the effects of visceral adiposity. The study aimed to investigate the associations between the visceral adiposity index (VAI) or lipid accumulation product (LAP) and frailty.

METHODS

This study used data from the National Health and Nutrition Examination Survey (NHANES), which included 5,279 participants aged ≥ 20 years. The VAI and LAP were calculated via recognized formulas, and frailty was evaluated via a deficit accumulation approach. We employed logistic regression and restricted cubic splines to assess the associations among LAP, VAI and frailty.

RESULTS

Out of 5,279 participants, 1,836 individuals were categorized as frail. According to the fully adjusted models, the highest VAI and LAP values were significantly associated with frailty, with adjusted ORs of 1.84 (95% CI: 1.40-2.42) and 2.47 (95% CI: 1.89-3.24), respectively, compared with the lowest values. A nonlinear relationship was identified between the LAP and frailty, with an inflection point of 1.589 (ln-transformed), whereas the VAI was linearly associated with frailty. Sensitivity analyses confirmed the robustness of these associations.

CONCLUSION

The VAI and LAP are significantly related to frailty, highlighting the importance of visceral adiposity in frailty risk. These results increase the understanding of the metabolic underpinnings of frailty and may guide the development of targeted prevention strategies.

An explainable predictive model for anxiety symptoms risk among Chinese older adults with abdominal obesity using a machine learning and SHapley Additive exPlanations approach

Background

Early detection of anxiety symptoms can support early intervention and may help reduce the burden of disease in later life in the elderly with abdominal obesity, thereby increasing the chances of healthy aging. The objective of this research is to formulate and validate a predictive model that forecasts the probability of developing anxiety symptoms in elderly Chinese individuals with abdominal obesity.

Method

This research's model development and internal validation encompassed 2,427 participants from the 2017-2018 Study of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Forty-six variables were defined based on the Health Ecology Model (HEM) theoretical framework. Key variables were screened using LASSO regression, and the XGBoost (Extreme Gradient Boosting) model was further introduced to forecast the risk of developing anxiety symptoms in the elderly with abdominal obesity. SHapley Additive exPlanations (SHAP) was adopted to further interpret and show how the eigenvalues contributed to the model predictions.

Results

A total of 240 participants (9.89%) with anxiety symptoms out of 2,427 participants were included. LASSO regression identified nine key variables: looking on the bright side, self-reported economic status, self-reported quality of life, self-reported health status, watching TV or listening to the radio, feeling energetic, feeling ashamed/regretful/guilty, feeling angry, and fresh fruits. All the evaluation indicators of the XGBoost model showed good predictive efficacy. Based on the significance of the features identified by SHAP (Model Interpretation Methodology), the feature 'looking on the bright side' was the most important, and the feature 'self-reported quality of life' was the least important. The SHAP beeswarm plot illustrated the impacts of features affected by XGBoost.

Conclusion

Utilizing machine learning techniques, our predictive model can precisely evaluate the risk of anxiety symptoms among elderly individuals with abdominal obesity, facilitating the timely adoption of targeted intervention measures. The integration of XGBoost and SHAP offers transparent interpretations for customized risk forecasts.

The association between continuing work after retirement and the incidence of frailty: evidence from the China health and retirement longitudinal study

OBJECTIVES

Retirement represents a significant life transition, with post-retirement status serving as a pivotal aspect of aging research. Despite its potential significance, little research has delved into the relationship between continuing work after retirement and the frailty. This study aims to investigate the association between continuing work after retirement and the incidence of frailty among older individuals.

DESIGN

A nationally representative cohort study.

SETTING AND PARTICIPANTS

We utilized data from 4 waves (2011, 2013, 2015 and 2018) of the China Health and Retirement Longitudinal Study and a total of 5,960 participants were included in the study after applying specific inclusion and exclusion criteria.

METHODS

Frailty was assessed using a Frailty Index. To balance baseline covariates between workers (n = 3,170) and non-workers (n = 2,790), we employed inverse propensity of treatment weighting. The relationship between work status and the incidence of frailty was examined using Cox proportional hazards analysis, with results reported as hazard ratios and 95% confidence intervals.

RESULTS

A total of 5,960 participants (mean age 64 years; 42.1% male) were included in the analysis. Over a mean follow-up of 6.9 years, 2,105 cases of frailty were identified. In the cohort analysis, following adjustment using the inverse propensity of treatment weighting (IPTW), continuing work after retirement showed a negative association with frailty incidence, with an HR of 0.72 (95% CI, 0.65-0.79). Subgroup analysis revealed a more significant protective effect of continuing work beyond retirement age among individuals aged 65 or older, males, smokers, and those with limited social activities.

CONCLUSIONS

In summary, this study identified a significant association between continuing work after retirement and a decreased risk of frailty. The findings underscore the potential benefits of policies promoting social engagement and extending working life in enhancing the quality of life for the aging population.

Effects of activities participation on frailty of older adults in China

Objective

Frailty represents a significant health challenge among older adults, necessitating effective interventions to enhance their overall wellbeing. This study aims to investigate the impact of various types of activity participation on frailty in older adults and to elucidate their intrinsic associations, thereby providing a basis for targeted interventions.

Methods

This study constructed a classification of activities based on the framework proposed by the WHO regarding functional ability in healthy aging, innovatively dividing activities into five categories: physical activity, social activity, economic activity, information activity and sleep activity. Utilizing data from the China Health and Retirement Longitudinal Study (CHARLS 2020), the research employed multiple linear regression and mediation analysis to explore the effects of these activities on the frailty status of older adults and their underlying mechanisms. Furthermore, propensity score matching was conducted to robustly test the regression results.

Results

The study found that physical activity (β = -0.006, p < 0.01), social activity (β = -0.007, p < 0.01), economic activity (β = -0.017, p < 0.01), information activity (β = -0.040, p < 0.01) and sleep activity (β = -0.044, p < 0.01) all had significant positive effects on the frailty status of older adults. Additionally, sleep activity mediated the relationship between physical activity and frailty status, accounting for 4.819%. Social activity mediated the relationship between information activity and frailty status, accounting for 7.692%.

Conclusion

Older adults should enhance their participation in various activities to alleviate frailty. This can be further improved through the following three aspects: engaging in moderate physical exercise, fostering and promoting awareness of volunteer services, and popularizing the use of information technology.

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.

Association of the triglyceride-glucose index and its related parameters with frailty

BACKGROUND

Frailty is a dynamic geriatric condition. Limited studies have examined the association of the triglyceride-glucose (TyG) index and its related indicators [TyG index, triglyceride glucose-waist to height ratio (TyG-WHtR), triglyceride glucose-waist circumference (TyG-WC), and triglyceride glucose-body mass index (TyG-BMI)] with frailty, and the potential links among them remain unclear. On the basis of data from the National Health and Nutrition Examination Survey (NHANES), this study investigated the potential relationships of the TyG index and its related indices with frailty.

METHODS

This research included 7,965 participants from NHANES 2003-2018. The relationship of the TyG index and its related indices with frailty was investigated with binary logistic regression analyses, restricted cubic spline (RCS), and receiver operating characteristic (ROC) curve. Potential influences were further investigated through stratified analyses and interaction tests.

RESULTS

The prevalence of frailty in the participants of this study was 25.59%, with a average frailty index of 0.16 (0.00). In the three regression analysis models, the continuous TyG index and its associated indices were positively associated with frailty. In addition, quartiles of TyG, TyG-WC, TyG-WHtR, and TyG-BMI were significantly associated with increased frailty prevalence in the fully adjusted models (TyG Q4 vs. Q1, OR = 1.58, 95% CI: 1.19, 2.09, P = 0.002; TyG-WC Q4 vs. Q1, OR = 2.40, 95% CI: 1.90, 3.04, P < 0.001; TyG-WHtR Q4 vs. Q1, OR = 2.26, 95% CI: 1.82, 2.81, P < 0.001; TyG- BMI Q4 vs. Q1, OR = 2.16, 95% CI: 1.76, 2.64, P < 0.001). According to RCS analysis, TyG, TyG-WC, TyG-WHtR, and TyG-BMI were linearly and positively associated with frailty. ROC curves revealed that TyG-WHtR (AUC: 0.654) had greater diagnostic value for frailty than TyG (AUC: 0.604), TyG-BMI (AUC: 0.621), and TyG-WC (AUC: 0.629). All of the stratified analyses and interaction tests showed similar results.

CONCLUSIONS

Elevated TyG and its associaed indices are associated with an increased prevalence of frailty. Reasonable control of blood glucose and blood lipids, and avoidance of obesity, may aid in reducing the occurrence of frailty in middle-aged and older adults.