Diagnosis, prevalence, and mortality of sarcopenia in dialysis patients: a systematic review and meta-analysis

Association between sarcopenia and frailty in elderly patients with chronic kidney disease

BACKGROUND

Frailty and sarcopenia are prevalent in chronic kidney disease (CKD) populations and could increase the risk for adverse health outcomes. Few studies assess the correlation between frailty, sarcopenia and CKD in non-dialysis patients. Therefore, this study aimed to determine frailty-associated factors in elderly CKD stage I-IV patients, expected to early identify and intervene in the frailty of elderly CKD patients.

METHODS

A total of 774 elderly CKD I-IV patients (>60 years of age) recruited from 29 clinical centers in China between March 2017 and September 2019 were included in this study. We established a Frailty Index (FI) model to evaluate frailty risk and verified the distributional property of FI in the study population. Sarcopenia was defined according to the criteria of the Asian Working Group for Sarcopenia 2019. Multinomial logistic regression analysis was used to assess the associated factors for frailty.

RESULTS

Seven hundred seventy-four patients (median age 67 years, 66.0% males) were included in this analysis, with a median estimated glomerular filtration rate of 52.8 mL/min/1.73 m² . The prevalence of sarcopenia was 30.6%. The FI exhibited a right-skewed distribution. The age-related slope of FI was 1.4% per year on a logarithmic scale (r²  = 0.706, 95% CI 0.9, 1.8, P < 0.001). The upper limit of FI was around 0.43. The FI was related to mortality (HR = 1.06, 95% CI 1.00, 1.12, P = 0.041). Multivariate multinomial logistic regression analysis showed that sarcopenia, advanced age, CKD stage II-IV, low level of serum albumin and increased waist-hip ratio were significantly associated with high FI status, while advanced age and CKD stage III-IV were significantly associated with for median FI status. Moreover, the results from the subgroup were consistent with the leading results.

CONCLUSIONS

Sarcopenia was independently associated with an increased risk for frailty in elderly CKD I-IV patients. Patients with sarcopenia, advanced age, high CKD stage, high waist-hip ratio and low serum albumin level should be assessed for frailty.

Sarcopenia and osteosarcopenia among patients undergoing hemodialysis

Background

Sarcopenia and osteoporosis are closely interconnected and associated with adverse health outcomes. Osteosarcopenia is the concurrent presence of the two conditions and has rarely been reported in hemodialysis patients. Whether hemodialysis patients with osteosarcopenia are at greater risk of mortality than those with either condition alone remains unknown. The aim of this study was to explore the prevalence of sarcopenia and its association with osteoporosis and to determine its impact on survival risk in hemodialysis patients.

Methods

A total of 209 adults undergoing hemodialysis were enrolled from the dialysis center in the West China Hospital of Sichuan University, and our study was registered at the Chinese Clinical Trial Register (number: ChiCTR2100043932). Muscle mass, handgrip strength, bone mineral density (BMD), and biochemical parameters were assessed. All deaths were recorded during a follow-up of 35.15 ± 15.37 months.

Results

Seventy-eight patients were diagnosed with sarcopenia, with a prevalence of 37.3%. After adjustment for potential confounders, age (OR=1.094, P <0.001), female sex (OR= 3.44, P =0.005), diabetes (OR=3.756, P =0.008), CRP (OR=1.09, P =0.015), serum magnesium (OR=0.755, p=0.042) and BMI (OR=0.701, P <0.001) were independently associated with sarcopenia. Among the 209 patients, 103 patients completed the BMD assessment. The prevalence of osteosarcopenia was 22.3%, while 20.4% of participants had sarcopenia alone and 12.6% had osteoporosis alone. The proportions of patients who died were 13.0% for nonsarcopenia&nonosteoporosis, 15.4% for osteoporosis alone, 47.6% for sarcopenia alone, and 52.2% for osteosarcopenia. Cox regression analysis showed that osteosarcopenia was independently associated with all-cause mortality (HR=3.74, 95% CI: 1.172-11.938), while osteoporosis alone and sarcopenia alone were not.

Conclusion

Patients undergoing hemodialysis had a high incidence of sarcopenia and osteosarcopenia, muscle mass and strength showed a significant association with BMD, and osteosarcopenia might have a powerful impact on mortality in those patients.

Clinical trial registration

http://www.chictr.org.cn/, identifier ChiCTR2100043932.

Clinical implications of circulating follistatin-like protein-1 in hemodialysis patients

Follistatin-like protein-1 (FSTL-1) is secreted glycoprotein, which regulates cardiovascular, immune and skeletal system. However, the clinical significance of circulating FSTL-1 levels remains unclear in hemodialysis patients. A total 376 hemodialysis patients were enrolled from June 2016 to March 2020. Plasma FSTL-1 level, inflammatory biomarkers, physical performance, and echocardiographic findings at baseline were examined. Plasma FSTL-1 levels were positively correlated with TNF-α and MCP-1. Handgrip strength showed weak positive correlation in male patients only, and gait speed showed no correlation with FSTL-1 levels. In multivariate linear regression analysis, FSTL-1 level was negatively associated with left ventricular ejection fraction (β =  - 0.36; p = 0.011). The cumulative event rate of the composite of CV event and death, and cumulative event rate of CV events was significantly greater in FSTL-1 tertile 3. In multivariate Cox-regression analysis, FSTL-1 tertile 3 was associated with a 1.80-fold risk for the composite of CV events and death(95% confidence interval (CI) 1.06-3.08), and a 2.28-fold risk for CV events (95% CI 1.15-4.51) after adjustment for multiple variables. In conclusion, high circulating FSTL-1 levels independently predict the composite of CV events and death, and FSTL-1 level was independently associated with left ventricular systolic dysfunction.

Epidemiology of sarcopenia: Prevalence, risk factors, and consequences

Sarcopenia is a geriatric condition featured by a progressive loss of muscle mass and function and associated with various adverse health outcomes. In this review, we aimed to summarize the epidemiological features of sarcopenia as well as consequences and risk factors of the disease. We performed a systematic review of meta-analysis on sarcopenia to collect data. The prevalence of sarcopenia varied between studies and depending on definition used. Sarcopenia was estimated to influence 10 %-16 % of the elderly worldwide. The prevalence of sarcopenia was higher among patients compared to general populations. The prevalence of sarcopenia ranged from 18 % in diabetic patients to 66 % in patients with unresectable esophageal cancer. Sarcopenia is associated with a high risk of a wide range of adverse health outcomes, including poor overall and disease-progression free survival rate, postoperative complications, and longer hospitalization in patients with different medical situations as well as falls and fracture, metabolic disorders, cognitive impairment, and mortality in general populations. Physical inactivity, malnutrition, smoking, extreme sleep duration, and diabetes were associated with an increased risk of sarcopenia. However, these associations were mainly based on non-cohort observational studies and need confirmation. High-quality cohort, omics, and Mendelian randomization studies are needed to deeply understand the etiological basis of sarcopenia.

Association of myosteatosis with treatment response and survival in patients with hepatocellular carcinoma undergoing chemoembolization: a retrospective cohort study

Patients with hepatocellular carcinoma (HCC) have poor prognosis and have frequent treatment-related toxicities resulting in cancer-associated cachexia. This study aimed to determine the association of myosteatosis and sarcopenia on mortality in patients with HCC treated with transarterial chemoembolization (TACE). Six hundred and eleven patients diagnosed with HCC and underwent TACE at a tertiary care center between 2008 and 2019 were included. Body composition was assessed using axial CT slices at level L3 to calculate the skeletal muscle density for myosteatosis and skeletal muscle index for sarcopenia. The primary outcome was overall survival while the secondary outcome was TACE response. Patients with myosteatosis had a poorer TACE response than patients without myosteatosis (56.12% vs. 68.72%, adjusted odds ratio [OR] 0.49, 95% confidence interval [CI] 0.34-0.72). The rate of TACE response in patients with sarcopenia was not different from those without sarcopenia (60.91% vs. 65.22%, adjusted OR 0.79, 95% CI 0.55-1.13). Patients with myosteatosis had shorter overall survival than without myosteatosis (15.9 vs. 27.1 months, P < 0.001). In the multivariable Cox regression analysis, patients with myosteatosis or sarcopenia had higher risk of all-cause mortality than their counterparts (adjusted hazard ratio [HR] for myosteatosis versus no myosteatosis 1.66, 95% CI 1.37-2.01, adjusted HR for sarcopenia versus no sarcopenia 1.26, 95% CI 1.04-1.52). Patients with both myosteatosis and sarcopenia had the highest 7 year mortality rate at 94.45%, while patients with neither condition had the lowest mortality rate at 83.31%. The presence of myosteatosis was significantly associated with poor TACE response and reduced survival. Identifying patients with myosteatosis prior to TACE could allow for early interventions to preserve muscle quality and might improve prognosis in HCC patients.

Bioelectrical impedance analysis-derived phase angle predicts sarcopenia in patients on maintenance hemodialysis

BACKGROUND

This study aimed to investigate the association between phase angle (PhA) and sarcopenia and evaluate its performance as a sarcopenia predictor in patients receveing maintenance hemodialysis (MHD).

METHODS

All enrolled patients underwent handgrip strength (HGS) and the 6-m walk test, and muscle mass was measured using bioelectrical impedance analysis. Sarcopenia was diagnosed according to the diagnostic criteria of the Asian Sarcopenia Working Group. Logistic regression analysis was used to evaluate the PhA as an independent predictor of sarcopenia after adjusting for confounding factors. The receiver operating characteristic (ROC) curve was used to analyze the predictive value of PhA in sarcopenia.

RESULTS

Two hundred forty-one patients receiving hemodialysis were enrolled in this study, and the prevalence of sarcopenia was 28.2%. Patients with sarcopenia presented a lower PhA value (4.7° vs 5.5°; P < 0.001), lower muscle mass index (6.0 vs 7.2 [kg/m² ]; P < 0.001), lower HGS (19.7 vs 26.0 [kg]; P < 0.001), and lower walk speed (0.83 ± 0.27 vs 0.92 ± 0.23 [m/s]; P = 0.007) than patients without sarcopenia. The odds of patients receiving MHD presenting with sarcopenia increased as PhA decreased, even after adjustment (odds ratio = 0.39; 95% CI, 0.18-0.85; P = 0.019). ROC analysis revealed that the best cutoff value of PhA for sarcopenia was 4.95° in patients receiving MHD.

CONCLUSION

PhA may be a useful and simple predictor for predicting patients undergoing hemodialysis who are at risk of sarcopenia. To further facilitate the application of PhA in the diagnosis of sarcopenia, more research need to be conducted.

Use machine learning to help identify possible sarcopenia cases in maintenance hemodialysis patients

BACKGROUND

Maintenance hemodialysis (MHD) patients often suffer from sarcopenia, which is strongly associated with their long-term mortality. The diagnosis and treatment of sarcopenia, especially possible sarcopenia for MHD patients are of great importance. This study aims to use machine learning and medical data to develop two simple sarcopenia identification assistant tools for MHD patients and focuses on sex specificity.

METHODS

Data were retrospectively collected from patients undergoing MHD and included patients' basic information, body measurement results and laboratory findings. The 2019 consensus update by Asian working group for sarcopenia was used to assess whether a MHD patient had sarcopenia. Finally, 140 male (58 with possible sarcopenia or sarcopenia) and 102 female (65 with possible sarcopenia or sarcopenia) patients' data were collected. Participants were divided into sarcopenia and control groups for each sex to develop binary classifiers. After statistical analysis and feature selection, stratified shuffle split and Synthetic Minority Oversampling Technique were conducted and voting classifiers were developed.

RESULTS

After eliminating handgrip strength, 6-m walk, and skeletal muscle index, the best three features for sarcopenia identification of male patients are age, fasting blood glucose, and parathyroid hormone. Meanwhile, age, arm without vascular access, total bilirubin, and post-dialysis creatinine are the best four features for females. After abandoning models with overfitting or bad performance, voting classifiers achieved good sarcopenia classification performance for both sexes (For males: sensitivity: 77.50% ± 11.21%, specificity: 83.13% ± 9.70%, F1 score: 77.32% ± 5.36%, the area under the receiver operating characteristic curves (AUC): 87.40% ± 4.41%. For females: sensitivity: 76.15% ± 13.95%, specificity: 71.25% ± 15.86%, F1 score: 78.04% ± 8.85%, AUC: 77.69% ± 7.92%).

CONCLUSIONS

Two simple sex-specific sarcopenia identification tools for MHD patients were developed. They performed well on the case finding of sarcopenia, especially possible sarcopenia.

Diagnosis, prevalence, and outcomes of sarcopenia in kidney transplantation recipients: A systematic review and meta-analysis

The prevalence of sarcopenia and its clinical predictors and clinical impact vary among kidney transplant recipients (KTRs), in part because of different diagnostic criteria. This study aimed to assess the reported diagnosis criteria of sarcopenia and compare them in terms of prevalence, clinical predictors, and impact of sarcopenia. The Medline, Embase, and Cochrane Library were searched for the full-length reports published until 28 January 2022. The subgroup analysis, meta-regression, and sensitivity analysis were performed and heterogeneity was assessed using the I² . A total of 681 studies were retrieved, among which only 23 studies (including 2535 subjects, 59.7% men, mean age 49.8 years) were eventually included in the final analysis. The pooled prevalence in these included studies was 26% [95% confidence interval (95% CI): 20-34%, I²  = 93.45%], including 22% (95% CI: 14-32%, I²  = 88.76%) in men and 27% (95% CI: 14-41%, I²  = 90.56%) in women (P = 0.554 between subgroups). The prevalence of sarcopenia diagnosed using low muscle mass was 34% (95% CI: 21-48%, I²  = 95.28%), and the prevalence of using low muscle mass in combination with low muscle strength and/or low physical performance was 21% (95% CI: 15-28%, I²  = 90.37%) (P = 0.08 between subgroups). In meta-regression analyses, the mean age (regression coefficient: 1.001, 95% CI: 0.991-1.011) and percentage male (regression coefficient: 0.846, 95% CI: 0.367-1.950) could not predict the effect size. Lower body mass index (odds ratio (OR): 0.57, 95% CI: 0.39-0.84, I²  = 61.5%), female sex (OR: 0.31, 95% CI: 0.16-0.61, I²  = 0.0%), and higher age (OR: 1.08, 95% CI: 1.05-1.10, I²  = 10.1%) were significantly associated with a higher risk for sarcopenia in KTRs, but phase angle (OR: 0.81, 95% CI: 0.16-4.26, I²  = 84.5%) was not associated with sarcopenia in KTRs. Sarcopenia was not associated with rejections (risk ratio (RR): 0.67, 95% CI: 0.23-1.92, I²  = 12.1%), infections (RR: 1.03, 95% CI: 0.34-3.12, I²  = 87.4%), delayed graft functions (RR: 0.81, 95% CI: 0.46-1.43, I²  = 0.0%), and death (RR: 0.95, 95% CI: 0.32-2.82, I²  = 0.0%) in KRTs. Sarcopenia was found to be very common in KRTs. However, we have not found that sarcopenia had a negative impact on clinical health after kidney transplantation. Large study cohorts and multicentre longitudinal studies in the future are urgently needed to explore the prevalence and prognosis of sarcopenia in kidney transplant patients.

Detection of sarcopenia using deep learning-based artificial intelligence body part measure system (AIBMS)

Background: Sarcopenia is an aging syndrome that increases the risks of various adverse outcomes, including falls, fractures, physical disability, and death. Sarcopenia can be diagnosed through medical images-based body part analysis, which requires laborious and time-consuming outlining of irregular contours of abdominal body parts. Therefore, it is critical to develop an efficient computational method for automatically segmenting body parts and predicting diseases. Methods: In this study, we designed an Artificial Intelligence Body Part Measure System (AIBMS) based on deep learning to automate body parts segmentation from abdominal CT scans and quantification of body part areas and volumes. The system was developed using three network models, including SEG-NET, U-NET, and Attention U-NET, and trained on abdominal CT plain scan data. Results: This segmentation model was evaluated using multi-device developmental and independent test datasets and demonstrated a high level of accuracy with over 0.9 DSC score in segment body parts. Based on the characteristics of the three network models, we gave recommendations for the appropriate model selection in various clinical scenarios. We constructed a sarcopenia classification model based on cutoff values (Auto SMI model), which demonstrated high accuracy in predicting sarcopenia with an AUC of 0.874. We used Youden index to optimize the Auto SMI model and found a better threshold of 40.69. Conclusion: We developed an AI system to segment body parts in abdominal CT images and constructed a model based on cutoff value to achieve the prediction of sarcopenia with high accuracy.

Leucine-enriched amino acid supplementation and exercise to prevent sarcopenia in patients on hemodialysis: a single-arm pilot study

Background

Sarcopenia, which is strongly associated with mortality and quality of life, occurs in up to 40% of hemodialysis patients. Here, we investigated the preventive effects of leucine-enriched amino acid supplementation and resistance exercise in non-sarcopenic hemodialysis patients, and characterized the biochemical and immunophenotypic profiles of those who benefited from the intervention.

Methods

Twenty-two patients on maintenance hemodialysis at our hospital were enrolled in this single center, prospective, single-arm pilot trial. For the first 12 weeks, the subjects were administered a total of 6 g of leucine per day. Three grams were supplied via capsules, and the remaining three grams were provided via beverages containing macro- and micro- nutrients, such as 10 μg of vitamin D and 290 mg of calcium. The supplements were not provided for the next 12 weeks. Muscle mass, grip strength, and physical performance were measured using the bioimpedance analyzer (BIA), handgrip strength (HGS), and short physical performance battery (SPPB) protocols, respectively, at baseline, 12 weeks, and 24 weeks. In addition, serum biochemistry, immunophenotype of peripheral blood mononuclear cells, and nutritional status was assessed at the three time points. Those who showed 5% or more improvement in parameters were defined as responders, otherwise, as non-responders (ClinicalTrials.gov identification number: NCT04927208).

Results

Twenty-one out of twenty-two patients (95.4%) showed improvement in at least one or more parameters among muscle mass, grip strength, and physical performance. After 12 weeks of intervention, skeletal muscle index was increased in 14 patients (63.6%), and grip strength was improved in 7 patients (31.8%). Baseline grip strength lower than 35.0 kg was the strongest predictor of improvement in grip strength (AUC 0.933 from ROC curve). Grip strength showed a significant increase in females than males (7.6 ± 8.2 vs. -1.6 ± 7.2%, p = 0.03), in age over 60 than under 60 (5.3 ± 6.2 vs. -1.4 ± 9.1%, p = 0.04), and in higher (≥95%) than lower (<95%) exercise compliance (6.8 ± 7.7 vs. -3.2 ± 6.4%, p = 0.004). In SPPB study, gait speed and sit-to-stand time was improved in 13 patients (59.1%) and 14 patients (63.6%), respectively. Baseline hemoglobin lower than 10.5 g/dl and hematocrit lower than 30.8% were predictor of improvement in the sit-to-stand time (AUC 0.862 and 0.848, respectively). Serum biochemistry results showed that, compared to non-responders, responders in muscle mass had lower baseline monocyte fraction (8.4 ± 1.9 vs. 6.9 ± 1.1%, p = 0.03), and responders in grip strength had lower baseline total protein (6.7 ± 0.4 vs. 6.4 ± 0.3 g/dL, p = 0.04). Immunophenotypic analysis found that the intervention tended to increase the naïve/memory CD8+ T cell ratio (from 1.2 ± 0.8 to 1.4 ± 1.1, p = 0.07).

Conclusion

Leucine-enriched amino acid supplementation and resistance exercise induced significant improvement in muscle mass, strength, and physical function in subpopulation of the non-sarcopenic hemodialysis patients. Those who benefited from the intervention were old-age females with lower baseline grip strength or lower hemoglobin or hematocrit, and who have good exercise compliance. Therefore, we propose that the intervention will help to prevent sarcopenia in selected patients on maintenance hemodialysis.

High prevalence of sarcopenia and myosteatosis in patients undergoing hemodialysis

BACKGROUND AND PURPOSE

Sarcopenia is highly prevalent (28.5-40.3%) in patients undergoing hemodialysis and leads to poor clinical outcomes. However, the association between muscle quality and sarcopenia in patients receiving hemodialysis remains unclear. Therefore, we aimed to explore the association between muscle cross-sectional area (CSA) and proton-density fat-fraction (PDFF) in patients with sarcopenia undergoing hemodialysis.

METHODS

Seventy-six patients undergoing hemodialysis for > 3 months were enrolled. Their handgrip strength (HGS), short physical performance battery (SPPB) performance, and appendicular skeletal muscle mass index (ASMI) were measured. Sarcopenia was defined using the Asian Working Group for Sarcopenia 2019 consensus update. All patients underwent quantitative magnetic resonance imaging. CSA and PDFF were measured for the thigh, trunk, and gluteus muscles.

RESULTS

The prevalence of probable, confirmed, and severe sarcopenia in this study was 73.7%, 51.3%, and 22.4%, respectively. Older age (OR: 1.061, P < 0.003); lower body mass index (BMI) (OR: 0.837, P = 0.008), albumin (OR: 0.765, P = 0.004), prealbumin (OR: 0.987, P = 0.001), predialysis blood urea nitrogen (BUN) (OR: 0.842, P < 0.001), predialysis creatinine (OR: 0.993, P < 0.001), phosphorus (OR: 0.396, P = 0.047); lower CSA of the thigh (OR: 0.58, P = 0.035), third lumbar (L3) trunk (OR: 0.37, P = 0.004), gluteus minimus and medius (OR: 0.28, P = 0.001), and gluteus maximus (OR: 0.28, P= 0.001); and higher PDFF of the thigh (OR: 1.89, P = 0.036) and L3 trunk (OR: 1.71, P = 0.040) were identified as sarcopenia risk factors. The gluteus minimus and medius CSA was lower in patients with sarcopenia than in those without after adjusting for age and BMI (OR: 0.37, P = 0.017). Higher thigh (P = 0.031) and L3 trunk (P = 0.006) muscle PDFF were significantly associated with lower HGS. Furthermore, higher thigh (P = 0.011) and L3 trunk (P = 0.010) muscle PDFF were also inversely correlated with lower ASMI.

CONCLUSION

Our findings demonstrate the high prevalence of sarcopenia and myosteatosis in patients undergoing hemodialysis and might trigger a paradigm shift in intervention strategies for patients receiving hemodialysis.

A Higher Whole-Body Extracellular to Intracellular Water Ratio Is Associated with Increased Odds of Cognitive Impairment in Hemodialysis Patients

BACKGROUND

Cognitive impairment (CI) is highly prevalent in patients undergoing hemodialysis. Whether fluid overload with malnutrition as assessed by the ratio of extracellular water to intracellular water (ECW/ICW) is associated with CI in patients on maintenance hemodialysis (MHD) has yet to be studied.

OBJECTIVE

This study aimed to investigate the association between ECW/ICW and CI in patients with MHD.

METHODS

We conducted a multicenter, cross-sectional study that enrolled 3,025 adult patients with MHD. Cognitive function was assessed through the Mini-Mental State Examination. The ECW/ICW was derived from a portable body composition monitor and analyzed by quartiles.

RESULTS

23.04% of participants had CI in our study. The prevalence of CI tended to increase as the quartiles of the ECW/ICW ratio increased. Unadjusted analysis showed that participants in quartile 4 were 3.02 times more likely to have a CI compared to those in quartile 1. After adjusting for age, sex, education, smoking status, body mass index, dialysis vintage, history of hypertension, and history of stroke, the adjusted OR (95% CI) for the highest quartile of ECW/ICW ratio was 1.36 (1.01, 1.83) for CI compared with the lowest quartile. Interestingly, the association between ECW/ICW ratio and CI persisted across all subgroups stratified by age, gender, history of diabetes, and stroke. (p for interaction > 0.05 for all).

CONCLUSION

An increased ECW/ICW ratio is associated with higher odds of cognitive impairment in patients undergoing hemodialysis.

The Association of Sarcopenia and Central Obesity with Mortality Risk in Patients with Chronic Kidney Disease - a 2-Year Observational Study

Background

Patients with chronic kidney disease (CKD) face numerous challenges regarding their nutritional status, including undernutrition, wasting, overweight, and obesity. However, there is a gap in the knowledge on the importance of nutritional status on the survival of CKD in patients along the spectrum of progression of CKD.

Objectives

This study aimed to investigate the association of several nutritional measures with all-cause mortality. The hypothesis was that indicators of nutritional status exceeding BMI are associated with increased mortality risk.

Methods

One-hundred seventy adult patients with predialysis CKD (n = 82), receiving hemodialysis (n = 42) or kidney transplantation (n = 46) were recruited from 2014 to 2019. At baseline, nutritional status was assessed by anthropometry, body composition, and muscle function by handgrip strength. Patient survival was assessed after a 2-y follow-up by Cox regression models adjusted for age, sex, and renal function and generalized additive models.

Results

Thirty-one patients (18%) died during the 2-y follow-up. Sarcopenia (n = 30) was associated with an increased risk of death (HR: 2.92; 95% CI: 1.24, 6.89), whereas central obesity (n = 82) was not associated with mortality (1.05; 0.51, 2.15) in the Cox regression analyses. An association between BMI and mortality risk per unit increase (0.97; 0.90, 1.05) was not observed. Other markers of nutritional status were inversely associated with mortality risk, including handgrip strength (0.89; 0.83, 0.95), mid-upper arm circumference (0.86; 0.78, 0.95), and phase angle (per 0.1 degree increase 0.86; 0.81, 0.92). In the generalized additive models, U-shaped relationships were observed between mortality risk and waist circumference and mid-upper arm muscle circumference, while BMI < 22 kg/m2 was associated with increased mortality risk.

Conclusions

Sarcopenia, but not central obesity was associated with total mortality in patients with CKD. The inclusion of muscle strength and mass measures in clinical practice should be considered.

The "adult inactivity triad" in patients with chronic kidney disease: A review

Background

The "pediatric inactivity triad" framework consists of three complex, interrelated conditions influencing physical inactivity and associated health risks. Evidence on the beneficial effects of physical activity in adults with chronic kidney disease (CKD) continues to grow, but few studies have explored the complex interactions behind inactivity in this population.

Results

Based on the "pediatric inactivity triad" framework and prior research, we would like to propose a new concept, the "adult inactivity triad" in CKD, including (1) exercise deficit disorder, (2) sarcopenia, and (3) physical illiteracy. Individuals can shift from "adult inactivity triad" to "adult activity triad" and move at different rates and directions along the arrows in each of the three components.

Conclusion

This review explores and summarizes previous research on the three main adult inactivity triad components in the chronic kidney disease population.

The triglyceride-glucose index as a novel marker associated with sarcopenia in non-diabetic patients on maintenance hemodialysis

Objective

Sarcopenia is a common complication in patients with end-stage kidney disease. Insulin resistance is present in non-diabetic patients undergoing maintenance hemodialysis (MHD) and is an important factor leading to sarcopenia. The triglyceride–glucose (TyG) index, a reliable indicator for evaluating insulin resistance, is widely used in clinical practice. The present study investigated the association between the TyG index and sarcopenia in non-diabetic patients undergoing MHD.

Methods

Relevant clinical data of non-diabetic patients undergoing MHD at our center were collected. The TyG index was calculated using the following formula: ln(fasting triglycerides(mg/dL)×fasting blood glucose(mg/dL)/2). Multivariate logistic regression analyses were used to evaluate the associations. The receiver-operating characteristic curve was used to analyze the predictive value of the TyG index in sarcopenia.

Results

Of the 142 patients undergoing MHD who were included, 75 (52.82%) were men, the mean age was 54.05 ± 13.97 years, and 40 (28.17%) patients satisfied the diagnostic criteria for sarcopenia. The TyG index of participants with sarcopenia was higher compared with those without sarcopenia (8.83 ± 0.45 vs. 8.49 ± 0.50, p < 0.001). The prevalence of sarcopenia increased with increasing TyG index tertile (T1, 8.51%; T2, 31.91%; T3, 43.75%; p = 0.001). Logistic regression analysis indicated that the TyG index was an independent risk factor for sarcopenia (odds ratio, 4.21 [95% confidence interval, 1.85–9.59], p = 0.001).

Conclusion

A higher TyG index was associated with an increased risk of sarcopenia in non-diabetic patients undergoing MHD; it may be used as a novel marker to reflect the presence of sarcopenia.

Simplified discriminant parameters for sarcopenia among patients undergoing haemodialysis

BACKGROUND

Patients with end-stage renal disease (ESRD) are at an increased risk of developing sarcopenia, which can lead to various adverse health outcomes. Although the diagnosis of sarcopenia is essential for clinical management, it is not feasible in routine clinical practice for populations undergoing haemodialysis because it is time-consuming and resources are limited. Serum creatinine levels in patients with ESRD have been gaining attention as a screening parameter for sarcopenia because serum creatinine is a routinely measured byproduct of skeletal muscle metabolism. This study aimed to evaluate the discriminative ability of the creatinine-derived index for sarcopenia in patients undergoing haemodialysis.

METHODS

We diagnosed sarcopenia according to the Asian Working Group for Sarcopenia (AWGS) 2 criteria in 356 clinically stable outpatients with ESRD enrolled from three dialysis facilities. We adopted the modified creatinine index as a simplified discriminant parameter for sarcopenia in addition to the calf circumference, SARC-F score, and combination of both (i.e. SARC-CalF score), which are recommended by the AWGS. Receiver operating characteristic analysis and logistic regression analysis were conducted to evaluate the discriminative ability of the modified creatinine index for sarcopenia.

RESULTS

Of the study participants, 142 (39.9%) were diagnosed with sarcopenia. The areas under the curve of the modified creatinine index against sarcopenia in the male and female participants were 0.77 (95% confidence interval [CI]: 0.71 to 0.83) and 0.77 (95% CI: 0.69 to 0.85), respectively. All simplified discriminant parameters were significantly associated with sarcopenia, even after adjusting for patient characteristics and centre. In the comparison of the odds ratios for sarcopenia for 1-standard deviation change in the simplified discriminant parameters, the odds ratio of the modified creatinine index was 1.92 (95% CI: 1.15 to 3.19), which was lower than that of the calf circumference (odds ratio: 6.58, 95% CI: 3.32 to 13.0) and similar to that of the SARC-F (odds ratio: 1.57, 95% CI: 1.14 to 2.16) and SARC-CalF scores (odds ratio: 2.36, 95% CI: 1.60 to 3.47).

CONCLUSIONS

This study revealed a strong association between the creatinine-derived index and sarcopenia in patients undergoing haemodialysis. The modified creatinine index was equal or superior to those of SARC-F and SARC-CalF score in discriminability for sarcopenia. However, the ability of the calf circumference to discriminate sarcopenia is extremely high, and further study is needed to determine whether it can be used to detect deterioration of muscle mass and function over time.

Sarcopenia and echocardiographic parameters for prediction of cardiovascular events and mortality in patients undergoing maintenance hemodialysis

Background

Sarcopenia is prevalent and is associated with the occurrence of cardiovascular complications in patients undergoing maintenance hemodialysis (MHD). It is unknown how skeletal muscle may be associated with aspects of myocardial structure and function. This study aimed to evaluate the association between sarcopenia and cardiac structure and function in patients undergoing MHD. We also examined the prognostic role of sarcopenia for mortality and cardiovascular events (CVE) in this population.

Methods

Participants from a single center underwent bioimpedance body composition analysis to measure skeletal muscle and echocardiography to assess myocardial structure and function. Sarcopenia was diagnosed based on the Asian Working Group for Sarcopenia criteria. The end points were all-cause mortality and CVE.

Results

Of the 158 participants, 46 (29.1%) had sarcopenia, 102 (64.6%) had left ventricular diastolic dysfunction (LVDD), and 106 (67.0%) had left ventricular hypertrophy (LVH). Participants with sarcopenia had smaller right ventricular sizes (2.54 ± 0.77 vs 2.76 ± 0.28; P < 0.01), inter-ventricular thickness (1.07 ± 0.19 vs 1.14 ± 0.20; P = 0.039), and left ventricular posterior wall thickness (0.96, 0.89-1.10 vs 1.06, 0.95-1.20; P = 0.018). Skeletal muscle mass was strongly correlated with left ventricular mass (LVM) (r = 0.577; P < 0.0001). Furthermore, the risk of LVDD (OR: 4.92, 95% confidence interval (CI) [1.73-13.95]) and LVH (OR: 4.88, 95% CI [1.08-21.96]) was much higher in the sarcopenic group than in the non-sarcopenic group. During a follow-up period of 18 months, 11 (6.9%) patients died, of which seven died (4.4%) of CVE, and 36 (22.8%) experienced CVE. The presence of sarcopenia (adjusted hazard ratio (HR), 6.59; 95% CI [1.08-39.91]; P = 0.041) and low skeletal muscle index (HR, 3.41; 95% CI [1.01-11.57]; P = 0.049) and handgrip strength (HR, 0.88; 95% CI [0.78-0.99]; P = 0.037) independently predicted death. Sarcopenia was a significant predictor of CVE (HR, 10.96; 95% CI [1.14-105.10]; P = 0.038).

Conclusion

Our findings demonstrated that sarcopenia is associated with LVDD and LVH, and is associated with a higher probability of death and CVE.

Frailty, sarcopenia and diabetic kidney disease: where do we stand?

The aim of this narrative non-systematic review was to investigate the potential interplay among frailty syndrome, sarcopenia and diabetic kidney disease (DKD) in type 2 diabetes mellitus (T2DM) patients. Data derived from a limited number of studies underline that DKD is a significant risk factor for frailty. On the other hand, frailty syndrome poses a higher risk for end-stage renal disease (ESRD) in subjects with DKD. In addition, frailty seems to affect the cognitive function and social life of DKD individuals, whilst as DKD deteriorates, there is a higher prevalence of sarcopenia which is a fundamental frailty factor. As a result, it is shown that a bidirectional relation is established between these entities, as diabetes mellitus (DM) affects the components of frailty and sarcopenia and vice versa. This vicious cycle is created through multiple pathophysiologic mechanisms, including the anabolic role of insulin, low-grade inflammation, cytokines and endothelial function, prompting further investigation in this area. Specific nutritional and exercise interventions are imperative to be established in order to ameliorate potential adverse outcomes, concerning these entities.

Sarcopenia and cardiovascular disease in patients with and without kidney disease: what do we know?

Cardiovascular disease (CVD) incidence is high in patients with chronic kidney disease (CKD) and is the most frequent cause of mortality in this population. Advanced age, hypertension, uremic toxins, endothelial dysfunction, atherosclerosis, hyperhomocysteinemia, oxidative stress, and inflammation are among the leading causes of increased CVD in advanced stages of CKD. Although defined as a decrease in muscle strength associated with aging, sarcopenia is also prevalent in CKD patients. Sarcopenia causes physical disability, low quality of life, and mortality. Regular exercise and nutritional supplementation may slow the progression of sarcopenia. Recent studies have shown that sarcopenia increases the risk of CVD and mortality in people with or without kidney disease. This review discusses the relationship between sarcopenia and CVD in light of the current literature.

Sarcopenia and sarcopenic obesity in chronic kidney disease: update on prevalence, outcomes, risk factors and nutrition treatment

PURPOSE OF REVIEW

This review summarizes literature from the last 18 months reporting on sarcopenia (or its components) in chronic kidney disease (CKD).

RECENT FINDINGS

The prevalence of sarcopenia in CKD is reported to be 5-62.5%, with higher rates observed later in the disease. Sarcopenic obesity rates are reported to be 2-23%. Sarcopenia in CKD is associated with increased risk of mortality, cardiovascular disease and vascular calcification. Risk factors include kidney disease itself and the impacts of CKD on lifestyle (reduced physical activity, diet changes). In earlier stages of CKD, if the risks from sarcopenia outweigh the risk of reaching end-stage renal disease, ensuring adequate energy intake combined with modest protein liberalization and physical activity may be indicated. Protein intakes above 1.3 g/kg of body weight per day should be avoided. For dialysis patients, interventions that provide a combination of carbohydrate, protein and fat appear more effective than those that provide protein alone, though it may take as long as 48 weeks for detectable changes in muscle mass.

SUMMARY

Sarcopenia is prevalent in CKD as kidney disease significantly impacts muscle mass and function. Nutrition interventions can improve components of sarcopenia, with an emphasis on adequate energy and protein.

Frailty, multimorbidity and sarcopaenia in haemodialysis patients

PURPOSE OF REVIEW

It is well recognised that haemodialysis patients have higher levels of multimorbidity, frailty and sarcopaenia. This review examines the current understanding of the three concepts in relation to the general population and haemodialysis patients, and the methods used to quantify them. It also looks at the interaction between multimorbidity, frailty and sarcopaenia in this patient group and proposes a new model that utilises muscle mass index and fat mass index as a surrogate representation of the three concepts.

RECENT FINDINGS

Multimorbidity in on the rise in the general population and this is one of the contributing factors to higher rates of chronic kidney disease, progression to end-stage renal disease and multimorbidity in haemodialysis patients. Malnutrition and haemodialysis induced end organ damage further contributes to muscle loss and frailty in this patient group. There is a significant overlap and interaction between multimorbidity, frailty and sarcopaenia in haemodialysis and their presence carries a significant impact on quality of life and survival. There are multiple scores for measuring multimorbidity, frailty and sarcopenia and there is no consensus on their utilisation in haemodialysis patients. We propose the use of fat mass index and muscle mass index model as a surrogate method for clinically quantifying multimorbidity, frailty and sarcopaenia.

SUMMARY

Effective public health policies are likely to have an impact on reducing the prevalence of multimorbidity and the development of end stage renal disease. Future research is required to develop interventions that are targeted at maintaining muscle mass and function in haemodialysis patients.

Gut microbiota as a promising therapeutic target for age-related sarcopenia

Sarcopenia is characterized by a progressive loss of skeletal muscle mass and function with aging. Recently, sarcopenia has been shown to be closely related with gut microbiota. Strategies such as probiotics and fecal microbiota transplantation have shown potential to ameliorate the muscle loss. This review will focus on the age-related sarcopenia, in particular on the relationship between gut microbiota and age-related sarcopenia, how gut microbiota is engaged in sarcopenia, and the potential role of gut microbiota in the treatment of age-related sarcopenia.

Association of serum 25-hydroxy vitamin D with gait speed and handgrip strength in patients on hemodialysis

BACKGROUND

Muscle dysfunction is prevalent in dialysis patients. Gait speed and handgrip strength are simple and reliable methods of assessing muscle function. Numerous observational studies have linked 25-hydroxy vitamin D[25(OH)D] status with gait speed and handgrip strength in populations without kidney diseases. This study aimed to evaluate the potential associations of 25(OH)D status with gait speed and handgrip strength in patients on hemodialysis.

METHODS

In this observational cross-sectional study, demographic data, biological data, and dialysis parameters were collected. Gait speed and handgrip strength were measured. Multiple linear regression and logistic regression analysis were used to investigate the relationship of 25(OH)D status with gait speed and handgrip strength after adjusting for potential confounders.

RESULTS

Overall, a total of 118 participants undergoing hemodialysis were included. Seventy-one (60.2%) participants were male. The median 25(OH)D status in participants was 11.58 (interquartile range: 8.51 to 15.41) ng/ml. When controlling for age, gender, dialysis vintage, and other confounders with a p-value < 0.15 in univariate analyses, 25(OH)D was significantly positively associated with gait speed (β = 0.16, 95% CI 0.05 to 0.28, p = 0.006) and handgrip strength (β = 3.83, 95% CI 1.09 to 6.56, p = 0.007).

CONCLUSION

Our study showed that 25(OH)D status seemed to be associated with gait speed and handgrip strength in patients on hemodialysis. However, these results were not robust. The relationships between 25(OH)D status and gait speed and handgrip should be further explored.

Comparison of three nutritional screening tools for detecting sarcopenia in patients with maintenance hemodialysis

Background

Malnutrition, dynapenia, and sarcopenia are prevalent conditions among patients with maintenance hemodialysis (MHD). They are related to numerous adverse health outcomes. The aim of this study was to compare the effect of three nutritional screening tools on predicting the risk of dynapenia and sarcopenia in patients with MHD.

Methods

From July 2020 to April 2021, a total of 849 patients with MHD were enrolled at seven different healthcare facilities in Shanghai, China in this multi-center cross-sectional study. Geriatric nutritional risk index (GNRI), malnutrition inflammation score (MIS), and creatinine (Cr) index were used for nutritional assessment. The cutoff values of muscle mass and strength to define dynapenia, pre-sarcopenia, and sarcopenia were based on the consensus by the Asia Working Group of Sarcopenia in 2019.

Results

Among 849, almost 60% were malnourished with the majority suffering from dynapenia (27.7%), followed by sarcopenia (22.7%), and pre-sarcopenia (6.2%).The area under the receiver-operating characteristic curve for GNRI was 0.722 [95% confidence interval (CI) = 0.684-0.760] and 0.723 (95% CI = 0.663-0.783) in predicting sarcopenia and pre-sarcopenia. The GNRI [odds ratio (OR) =6.28, 95% CI: 4.05-9.73], MIS (OR =1.91, 95% CI: 1.31-2.78), and the Cr index (OR =2.73, 95% CI: 1.71-4.34) were all significantly associated with the risk of sarcopenia. More importantly, the sarcopenia predictability of the GNRI appears greater than the MIS and Cr index, while MIS was similar to the Cr index. Similarly, the superiority of GNRI prediction was also found in pre-sarcopenia, but not in dynapenia.

Conclusion

All the three nutritional screening tools were significantly associated with an increased risk of sarcopenia. The sarcopenia predictability of the GNRI was greater than the MIS and Cr index.

Prevalence of Sarcopenia and Its Impact on Cardiovascular Events and Mortality among Dialysis Patients: A Systematic Review and Meta-Analysis

Sarcopenia in end-stage kidney disease patients requiring dialysis is a frequent complication but remains an under-recognized problem. This meta-analysis was conducted to determine the prevalence of sarcopenia and explored its impacts on clinical outcomes, especially cardiovascular events, and mortality in dialysis patients. The eligible studies were searched from PubMed, Scopus, and Cochrane Central Register of Controlled trials up to 31 March 2022. We included studies that reported the interested outcomes, and the random-effects model was used for analysis. Forty-one studies with 7576 patients were included. The pooled prevalence of sarcopenia in dialysis patients was 25.6% (95% CI 22.1 to 29.4%). Sarcopenia was significantly associated with higher mortality risk (adjusted OR 1.83 (95% CI 1.40 to 2.39)) and cardiovascular events (adjusted OR 3.80 (95% CI 1.79 to 8.09)). Additionally, both low muscle mass and low muscle strength were independently related to increased mortality risk in dialysis patients (OR 1.71; 95% CI (1.20 to 2.44), OR 2.15 (95% CI 1.51 to 3.07)), respectively. This meta-analysis revealed that sarcopenia was highly prevalent among dialysis patients and shown to be an important predictor of cardiovascular events and mortality. Future intervention research to alleviate this disease burden in dialysis patients is needed.

Development of a risk prediction nomogram for sarcopenia in hemodialysis patients

Background

Sarcopenia is associated with various adverse outcomes in hemodialysis patients. However, current tools for assessing and diagnosing sarcopenia have limited applicability. In this study, we aimed to develop a simple and reliable nomogram to predict the risk of sarcopenia in hemodialysis patients that could assist physicians identify high-risk patients early.

Methods

A total of 615 patients undergoing hemodialysis at the First Affiliated Hospital College of Medicine Zhejiang University between March to June 2021 were included. They were randomly divided into either the development cohort (n = 369) or the validation cohort (n = 246). Multivariable logistic regression analysis was used to screen statistically significant variables for constructing the risk prediction nomogram for Sarcopenia. The line plots were drawn to evaluate the effectiveness of the nomogram in three aspects, namely differentiation, calibration, and clinical net benefit, and were further validated by the Bootstrap method.

Results

The study finally included five clinical factors to construct the nomogram, including age, C-reactive protein, serum phosphorus, body mass index, and mid-upper arm muscle circumference, and constructed a nomogram. The area under the ROC curve of the line chart model was 0.869, with a sensitivity and specificity of 77% sensitivity and 83%, the Youden index was 0.60, and the internal verification C-statistic was 0.783.

Conclusions

This study developed and validated a nomogram model to predict the risk of sarcopenia in hemodialysis patients, which can be used for early identification and timely intervention in high-risk groups.

Comparison of various indices for predicting sarcopenia and its components in patients receiving peritoneal dialysis

This study aimed to evaluate and compare the usefulness of four indices-arm circumference, thigh circumference, mid-arm muscle circumference (MAMC), and thigh muscle circumference (TMC)-with that of other classical indicators of body composition in the prediction of sarcopenia and two sarcopenia-related components in patients receiving peritoneal dialysis (PD) grouped by sex. The data of all patients receiving PD who visited a tertiary medical center were collected (n = 214); of them 199 patients undergoing PD were included in the final analyses. Data on baseline characteristics and measurements, including circumferences of appendicular sites, handgrip strength (HGS), and appendicular lean mass (ALM) index, were obtained during a routine peritoneal membrane equilibration test. Body composition was evaluated using dual-energy X-ray absorptiometry. The ALM index (kg/m²) was defined as the sum of lean mass in the upper and lower extremities divided by height squared. Sarcopenia was defined as low HGS and low muscle mass based on the cut-off values in the Asian Working Group for Sarcopenia guideline. The circumferences of the lower extremities showed the greatest association with the ALM index in both sexes. Prediction of HGS was better with the MAMC than with the other indices in the male patients, whereas none of the indices were associated with HGS in the female patients. Moreover, the MAMC in the male patients and TMC in the female patients were the strongest predictors of sarcopenia among the six anthropometric indices. This study showed that the MAMC in male PD patients and TMC in female PD patients might be the best predictors of sarcopenia. However, the TMC was associated with sarcopenia regardless of HGS in the female PD patients. These findings suggest that, in PD patients, different indices should be considered in predicting sarcopenia or its components based on the sex.

Bibliometric Analysis of the Knowledge Base and Future Trends on Sarcopenia from 1999–2021

Sarcopenia is characterized by progressive loss of muscle mass and function, and it is becoming a serious public health problem with the aging population. However, a comprehensive overview of the knowledge base and future trends is still lacking. The articles and reviews with “sarcopenia” in their title published from 1999 to 2021 in the SCIE database were retrieved. We used Microsoft Excel, VOSviewer, and CiteSpace to conduct a descriptive and bibliometric analysis. A total of 3582 publications were collected, from 4 published in 2000 increasing dramatically to 850 documents in 2021. The USA was the most productive country, with the most citations. The Catholic University of the Sacred Heart and Landi F were the most influential organization and author in this field, respectively. The core journal in this field was the Journal of Cachexia Sarcopenia and Muscle. According to the analysis of keywords and references, we roughly categorized the main research areas into four domains as follows: 1. Definition and diagnosis; 2. Epidemiology; 3. Etiology and pathogenesis; 4. Treatments. Comparing different diagnostic tools and the epidemiology of sarcopenia in different populations are recent hotspots, while more efforts are needed in the underlying mechanism and developing safe and effective treatments. In conclusion, this study provides comprehensive insights into developments and trends in sarcopenia research that can help researchers and clinicians better manage and implement their work.

Hidden Agenda - The Involvement of Endoplasmic Reticulum Stress and Unfolded Protein Response in Inflammation-Induced Muscle Wasting

Critically ill patients at the intensive care unit (ICU) often develop a generalized weakness, called ICU-acquired weakness (ICUAW). A major contributor to ICUAW is muscle atrophy, a loss of skeletal muscle mass and function. Skeletal muscle assures almost all of the vital functions of our body. It adapts rapidly in response to physiological as well as pathological stress, such as inactivity, immobilization, and inflammation. In response to a reduced workload or inflammation muscle atrophy develops. Recent work suggests that adaptive or maladaptive processes in the endoplasmic reticulum (ER), also known as sarcoplasmic reticulum, contributes to this process. In muscle cells, the ER is a highly specialized cellular organelle that assures calcium homeostasis and therefore muscle contraction. The ER also assures correct folding of proteins that are secreted or localized to the cell membrane. Protein folding is a highly error prone process and accumulation of misfolded or unfolded proteins can cause ER stress, which is counteracted by the activation of a signaling network known as the unfolded protein response (UPR). Three ER membrane residing molecules, protein kinase R-like endoplasmic reticulum kinase (PERK), inositol requiring protein 1a (IRE1a), and activating transcription factor 6 (ATF6) initiate the UPR. The UPR aims to restore ER homeostasis by reducing overall protein synthesis and increasing gene expression of various ER chaperone proteins. If ER stress persists or cannot be resolved cell death pathways are activated. Although, ER stress-induced UPR pathways are known to be important for regulation of skeletal muscle mass and function as well as for inflammation and immune response its function in ICUAW is still elusive. Given recent advances in the development of ER stress modifying molecules for neurodegenerative diseases and cancer, it is important to know whether or not therapeutic interventions in ER stress pathways have favorable effects and these compounds can be used to prevent or treat ICUAW. In this review, we focus on the role of ER stress-induced UPR in skeletal muscle during critical illness and in response to predisposing risk factors such as immobilization, starvation and inflammation as well as ICUAW treatment to foster research for this devastating clinical problem.

The Impact of Falls: A Qualitative Study of the Experiences of People Receiving Haemodialysis

The prevalence of falls is high in people receiving haemodialysis (HD). This study aimed to explore the experiences of people receiving HD who had fallen in the last six months. A qualitative study, informed by constructivist grounded theory, used semi-structured interviews in combination with falls diaries. Twenty-five adults (mean age of 69 ± 10 years, 13 female, 13 White British) receiving HD with a history of at least one fall in the last six months (median 3, IQR 2–4) participated. Data were organised within three themes: (a) participants’ perceptions of the cause of their fall(s): poor balance, weakness, and dizziness, exacerbated by environmental causes, (b) the consequences of the fall: injuries were disproportionate to the severity of the fall leading to loss of confidence, function and disruptions to HD, (c) reporting and coping with falls: most did not receive any specific care regarding falls. Those who attended falls services reported access barriers. In response, personal coping strategies included avoidance, vigilance, and resignation. These findings indicate that a greater focus on proactively identifying falls, comprehensive assessment, and timely access to appropriate falls prevention programmes is required to improve care and outcomes.

Diagnosis, prevalence, and mortality of sarcopenia in dialysis patients: a systematic review and meta-analysis

There is no consensus on the prevalence of sarcopenia or its impact on mortality in end-stage renal disease patients undergoing dialysis. This review aimed to summarize the diagnostic criteria of sarcopenia and its prevalence and impact on the mortality of end-stage renal disease patients undergoing dialysis. Embase, MEDLINE, PubMed, and Cochrane Library were searched from inception to 8 May 2021 to retrieve eligible studies that assessed muscle mass by commonly used instruments, such as dual-energy X-ray absorptiometry, bioelectrical impedance analysis, magnetic resonance imaging, and body composition monitor. Two assessment tools matched to study designs were employed to evaluate study quality. Pooled sarcopenia prevalence was calculated with 95% confidence interval (CI), and heterogeneity was estimated using the I2 test. Associations of sarcopenia with mortality were expressed as hazard ratio (HR) and 95% CI. The search identified 3272 studies, and 30 studies (6162 participants, mean age from 47.5 to 77.5 years) were analysed in this review. The risk of bias in the included studies was low to moderate. Twenty-two studies defined sarcopenia based on low muscle mass (LMM) plus low muscle strength and/or low physical performance, while eight studies used LMM alone. Muscle mass was assessed by different instruments, and a wide range of cut-off points were used to define LMM. Overall, sarcopenia prevalence was 28.5% (95% CI 22.9-34.1%) and varied from 25.9% (I2  = 94.9%, 95% CI 20.4-31.3%; combined criteria) to 34.6% (I2  = 98.1%, 95% CI 20.9-48.2%; LMM alone) (P = 0.247 between subgroups). The statistically significant differences were not found in the subgroups of diagnostic criteria (P > 0.05) and dialysis modality (P > 0.05). Additionally, the sarcopenia prevalence could not be affected by average age [regression coefficient 0.004 (95% CI: -0.005 to 0.012), P = 0.406] and dialysis duration [regression coefficient 0.002 (95% CI -0.002 to 0.005), P = 0.327] in the meta-regression. The pooled analyses showed that combined criteria of sarcopenia were related to a higher mortality risk [HR 1.82 (I2  = 26.3%, 95% CI 1.38-2.39)], as was LMM [HR 1.61 (I2  = 26.0%, 95% CI 1.31-1.99)] and low muscle strength [HR 2.04 (I2  = 80.4%, 95% CI 1.19-3.5)]. Although there are substantial differences in diagnostic criteria, sarcopenia is highly prevalent in dialysis patients and is linked to increased mortality. The standardization of sarcopenia diagnostic criteria would be beneficial, and future longitudinal studies are needed to investigate the prevalence and prognostic value of sarcopenia in dialysis patients.