Muscle strength performed better than muscle mass in identifying cognitive impairment risk in maintenance hemodialysis patients

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.

Muscle density, but not size, is independently associated with cognitive health in older adults with hip fractures

Emerging evidence indicates a complex interplay between skeletal muscle and cognitive function. Despite the known differences between muscle quantity and quality, which can be measured via computed tomography (CT), the precise nature of their associations with cognitive performance remain underexplored. To investigate the links between muscle size and density and cognitive impairment (CI) in the older adults with hip fractures, we conducted a post hoc, cross-sectional analysis within a prospective cohort study on 679 patients with hip fractures over 65. Mini-Mental State Examination (MMSE) and routine hip CT imaging were utilized to assess cognition function and muscle characteristics in older adults with hip fractures. The CT scans provided data on cross-sectional area and attenuation for the gluteus maximus (G.MaxM) and the combined gluteus medius and minimus (G.Med/MinM). Participants were categorized into CI and non-CI groups based on education levels and MMSE scores. Multivariate logistic regressions, propensity score (PS) methods, and subgroup analysis were employed to analyze associations and validate findings. This study included 123 participants (81.6 ± 6.8 years, 74% female) with CI and 556 participants (78.5 ± 7.7 years, 72% female) without. Compared to the non-CI group, muscle parameters, especially density, were significantly lower in the CI group. Specifically, G.Med/Min muscle density, but not size was robustly associated with CI (odds ratio (OR) = 0.77, 95% confidence interval = 0.62-0.96, P = 0.02), independent of other medical situations. Sensitivity analysis corroborated that G.Med/Min muscle density was consistently lower in the CI group than the non-CI group, as evidenced in the PS matched (P = 0.024) and weighted cohort (P = 0.033). Enhanced muscle parameters, particularly muscle density in the G.Med/MinM muscle, correlate with a lower risk of CI. Muscle density demonstrates a stronger association with cognitive performance than muscle size, highlighting its potential as a key focus in future cognitive health research.

Increased extracellular water/body mass is associated with functional impairment in hemodialysis patients

BACKGROUND

Functional impairment, malnutrition and fluid overload are prevalent in patients undergoing maintenance hemodialysis (MHD). The extracellular water/body cell mass ratio (ECW/BCM) is a new indicator reflecting fluid overload and malnutrition. A previous study has suggested that it performs better than other indices in assessing fluid status. This study investigates the relationship between pre-dialysis whole-body ECW/BCM and physical function in MHD patients.

METHODS

We conducted a multicenter, cross-sectional study in Guizhou Province in Southwest China. The Karnofsky Performance Status (KPS) was used to evaluate patients' functional status. Patients with KPS scores of ≤ 80 were considered to have a functional impairment. The body composition was measured using the body composition monitor (BCM), and the value of the ECW/BCM ratio was calculated. The subjects were classified into three groups according to ECW/BCM tertiles. Multiple logistic regression models and interactive analyses were conducted.

RESULTS

The final analysis included 2818 subjects. Multivariate logistic regression analyses showed that compared with the lowest tertile (tertile 1), the adjusted odds ratio of functional impairment were 1.95 (95% CI: 1.21-3.13, p < 0.001) and 2.10 (95% CI: 1.31-3.37, p < 0.001) in the second and the third tertiles of ECW/BCM, respectively after adjusting for age, sex, current smoking status, history of stroke, heart failure, diabetes, and myocardial infarction. Subgroup analysis showed that the association existed stably across all subgroups stratified by age, gender, cognitive impairment (CI), history of stroke, heart failure, and diabetes (all p values for interaction >0.05).

CONCLUSIONS

Elevated ECW/BCM is independently linked to an increased risk of functional impairment in patients with MHD.

Lean-to-fat tissue ratio as a risk factor for cognitive impairment in patients undergoing maintenance hemodialysis

OBJECTIVE

The relationship between body mass index (BMI) and cognitive impairment (CI) remains controversial, and no research has been done to explore the effect of lean-to-fat (L/F) tissue ratio on the risk of CI in patients undergoing maintenance hemodialysis (MHD) so far. This study aimed to explore the effect of L/F tissue ratio on the risk of incident CI in patients undergoing MHD.

METHODS

In this observational cohort study, 3356 patients were recruited and followed up for a median of 2 years. Global cognitive function was measured using Mini-Mental State Examination score. Lean tissue mass (LTM) and fat tissue mass (FTM) were analyzed using body composition monitor based on bioimpedance spectroscopy (BCM-BIS), and L/F tissue ratio was calculated by LTM divided by FTM. Hazard ratios (HRs) for incident CI were determined by Cox regression.

RESULTS

The median age of the cohort was 55 years, and 68.7% patients were less educated. During the follow-up period, 1249 patients (37.2%) experienced incident CI. Patients with lower L/F tissue ratios had significantly higher risks of CI (HR 1.51, 95% confidence interval 1.24-1.84; p < 0.001) than those with higher L/F tissue ratios. The association between L/F tissue ratio and incident CI persisted in all subgroups stratified by sex, age, education status, especially in older and less educated participants. Both in all our patients and subgroups, BMI and CI occurrence were not independently relevant.

CONCLUSION

The L/F tissue ratio rather than BMI was an independent risk factor of incident cognitive impairment in patients undergoing MHD.

Soluble interleukin 2 receptor is risk for sarcopenia in Men with high fracture risk

Background & aims

Sarcopenia is an age-related disease that increases the risk of falls and fractures in older adults. However, there is no blood biochemical marker to help to predict or diagnose sarcopenia in clinical practice. Soluble interleukin 2 receptor (sIL-2R) was reported to be associated with muscle satellite cell dysfunction which played an important role in the pathogenesis of sarcopenia. Thereby, we aimed to explore the association between serum sIL-2R and sarcopenia in older adults at high risk of fractures.

Methods

A total of 429 hospitalized older adults (age ≥55 years) were enrolled in this cross-sectional study (mean age ​= ​66.62 ​± ​6.59 years; 62.7% female). Logistic regression analysis was performed to assess the association of sIL-2R with sarcopenia, muscle mass, muscle strength, and physical performance, respectively. The optimal models for the diagnosis of sarcopenia and low hand grip strength (HGS) were established by multivariable binary logistic regression analysis with backward selection, and further were evaluated for the diagnostic values by receiver operating characteristic (ROC) curve.

Results

Higher sIL-2R levels were found in sarcopenia than no-sarcopenia group in male (median 421 U/mL (interquartile range [IQR] 217 U/mL) vs median 362 U/mL (IQR 157 U/mL); n ​= ​77 vs 83; p ​< ​0.01). Compared to the lowest sIL-2R tertile, the highest tertile of sIL-2R was independently associated with the risk of low HGS (odds ratio [OR] 4.608, 95% confidence interval [CI] 1.673–12.695) and the risk of sarcopenia (OR 3.306, 95% CI 1.496–7.302) in men. ROC curves revealed that the Area Under the Curve (AUC) of the optimal models for diagnosing sarcopenia and low HGS was 0.752 and 0.846.

Conclusion

Our results suggest that serum sIL-2R is the independent risk factor for sarcopenia and low muscle strength only in men. sIL-2R may be developed to be a biochemical marker for sarcopenia and low muscle strength diagnoses in older men at high risk of fractures, but more prospective studies are needed to prove it.

The translational potential of this article

Our results showed that the highest tertile of sIL-2R was independent of low risk of HGS and sarcopenia in men, compared to the lowest tertile. As the population ages, sIL-2R may become a potential diagnostic tool for predicting low HGS and sarcopenia among men at high risk of fractures.