Sarcopenia in CKD: a roadmap from basic pathogenetic mechanisms to clinical trials

Assessment of the components of sarcopenia and quality of life perceived of individuals on hemodialysis

OBJECTIVES

to evaluate the prevalence of sarcopenia in individuals aged 50 years or older on hemodialysis; to verify the association between sarcopenia and sociodemographic, clinical, anthropometric factors, components of sarcopenia and quality of life (QoL); and to correlate the components of sarcopenia with QoL.

METHODS

Participated 83 individuals on hemodialysis. Sarcopenia was established according to the current European consensus. Dynamometry to determine strength, calf circumference (CC) and appendicular skeletal muscle mass index (ASMMI) to obtain muscle mass and gait speed (GS) for physical performance. For QoL used the WHOQOL-bref.

RESULTS

the prevalence of sarcopenia was 32.6% (CC) and 18.1% (ASMMI). There was no association between sarcopenia and QoL. Both handgrip strength (r=0.25) and GS (r=0.36) showed a correlation with physical domain.

CONCLUSIONS

sarcopenia was expressive, and the aspects of functionality determine the physical impairment in this population.

Prevalence and associated risk factors for chronic kidney disease in the elderly physically disabled population in Shanghai, China: a cross-sectional study

BACKGROUND

The global prevalence of chronic kidney disease (CKD) in the general population is relatively clear. Our previous study showed that elderly individuals who are physically disabled are more likely to experience kidney function impairment, and the main purpose of this study was to determine the prevalence and risk factors associated with CKD in elderly patients with physical disabilities.

METHODS

A total of 2679 elderly individuals with physical disabilities from the 2018 Shanghai Disability Health Survey were screened to calculate the prevalence of CKD. Multiple logistic regression was performed to identify the factors associated with CKD. Detailed subgroup analyses of disability level were also conducted.

RESULTS

We confirmed CKD in 287 of 2679 (10.7%) participants. Female sex, age, history of hypertension, red blood cell count, albumin, urea, and uric acid (UA) were independently correlated with CKD. Age and UA abnormalities were common risk factors for different levels of disabilities.

CONCLUSION

The prevalence of CKD is higher in the mild level of older physically handicapped individuals. Age and the level of UA should also be considered in this population. The preventive strategies for patients with two levels of elderly disability should have different focuses.

Design and methodology of the SARCopenia trajectories and associations with adverse clinical outcomes in patients on HemoDialysis: the SARC-HD study

BACKGROUND

Sarcopenia has been associated with adverse outcomes in patients with chronic kidney disease (CKD), particularly in those undergoing hemodialysis (HD). However, the trajectories across sarcopenia stages, their determinants, and associations with adverse clinical outcomes have yet to be comprehensively examined.

METHODS

The SARC-HD is a multicenter, observational prospective cohort study designed to comprehensively investigate sarcopenia in patients on HD. Eligibility criteria include adult patients undergoing HD for ≥ 3 months. The primary objective is to investigate the trajectories of sarcopenia stages and their potential determinants. Secondary objectives include evaluating the association between sarcopenia and adverse clinical outcomes (i.e., falls, hospitalization, and mortality). Sarcopenia risk will be assessed by the SARC-F and SARC-CalF questionnaire. Sarcopenia traits (i.e., low muscle strength, low muscle mass, and low physical performance) will be defined according to the revised European Working Group on Sarcopenia in Older People and will be assessed at baseline and after 12 follow-up months. Patients will be followed-up at 3 monthly intervals for adverse clinical outcomes during 24 months.

DISCUSSION

Collectively, we expect to provide relevant clinical findings for healthcare professionals from nephrology on the association between sarcopenia screening tools (i.e., SARC-F and SARC-CalF) with objective sarcopenia measurements, as well as to investigate predictors of trajectories across sarcopenia stages, and the impact of sarcopenia on adverse clinical outcomes. Hence, our ambition is that the data acquired from SARC-HD study will provide novel and valuable evidence to support an adequate screening and management of sarcopenia in patients on HD.

Ultrasound for thigh muscle thickness is a valuable tool in the diagnosis of sarcopenia in Indian patients with predialysis chronic kidney disease

Objectives

Patients with chronic kidney disease (CKD) are known to develop sarcopenia, an aging-related disorder, with low muscle mass, strength and physical performance. Ultrasound-derived thigh muscle and rectus femoris thickness (TMT and RFT) can be measured easily in clinical practice, but need validation for use in predialysis CKD (stages III through V) for muscle mass estimation. The study aims to compare ultrasound-derived TMT and RFT with bioelectrical impedance analysis (BIA)-derived muscle mass estimation in the diagnosis of sarcopenia in predialysis CKD.

Methods

Patients with stable CKD stage III, IV, V and not yet on dialysis were recruited, and underwent anthropometric assessment, BIA and ultrasound examination of midthigh region. Appendicular skeletal muscle index (ASMI)/height² derived from BIA was taken as a standard for the diagnosis of low muscle mass. Gait speed and handgrip were also measured. The Asian Working Group criteria were applied. Cutoff values for low muscle mass by TMT and RFT were obtained using receiver operator curve (ROC) analysis.

Results

Of the total of 117 enrolled study participants, 52 (45%) had low muscle mass, 34 (29%) had sarcopenia, of whom 79% were male, majority (38%) were CKD stage IV and had a mean age of 58 years. Using ROC analysis, TMT cutoffs of 19 mm in males and 17 mm in females were computed. Comparison of TMT cutoffs and ASMI/h² showed good agreement between the 2 methods using Bland-Altman plots.

Conclusions

Ultrasound-derived TMT and RFT can be used for muscle mass estimation in the diagnosis of sarcopenia.

Sarcopenia in Patients With Spinal Metastasis: A Systematic Review and Meta-Analysis of Retrospective Cohort Studies

Background

As a metastasis cancer that happens up to 70% of the cancer patients, spinal metastasis is drawing attention for its significant impairment to health. There exist several predictive models designed to estimate mortality in spinal metastasis patients but they are reported with limited accuracy. In recent years, some retrospective cohort studies have been carried out to associate sarcopenia with mortality in spinal metastasis.

Introduction

As a risk factor leading to adverse events in many diseases, sarcopenia was considered to significantly impact on patients with spinal metastasis in mortality by some scientists. We aimed to look through the current evidence and use statistic measures to value the role of sarcopenia in spinal metastasis. In this study, we are going to perform a systematic review and meta-analysis of available retrospective cohort studies where sarcopenia is assessed for outcomes in spinal metastasis patients.

Methods

On October 7, 2021, we performed a search in PubMed, Embase, and the Cochrane Library. We set no restrictions on language, date or areas. Results were expressed as hazard ratio (HR) or odds ratio (OR) with 95% CI by random effects model. Sensitivity analyses were performed to explore sources of heterogeneity and stability of results.

Results

Of the 4,196 papers screened, 10 retrospective cohort studies were included, with a total of 1,674 patients. Results showed that sarcopenia was associated with higher overall mortality (OR, 1.60; 95% CI 1.35–1.90) and lower overall survival (HR, 2.08; 95% CI 1.55–2.80). The sensitivity analysis proved the stability of results in terms of publication years, region, time of diagnosis, sample size, female rate, measurement and follow up period.

Conclusions

Sarcopenia is a robust indicator of mortality in spinal metastasis patients and it might be applied to decision-making tools to assess survival probability and adjust the extent of treatment, while a lack of higher level of evidence is existing.

Systematic Review Registration

PROSPERO CRD42021283348.

The Effect of Non-Pharmacological and Pharmacological Interventions on Measures Associated with Sarcopenia in End-Stage Kidney Disease: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis provides a synthesis of the available evidence for the effects of interventions on outcome measures associated with sarcopenia in end-stage kidney disease (ESKD). Thirteen databases were searched, supplemented with internet and hand searching. Randomised controlled trials of non-pharmacological or pharmacological interventions in adults with ESKD were eligible. Trials were restricted to those which had reported measures of sarcopenia. Primary outcome measures were hand grip strength and sit-to-stand tests. Sixty-four trials were eligible (with nineteen being included in meta-analyses). Synthesised data indicated that intradialytic exercise increased hand grip strength (standardised mean difference, 0.58; 0.24 to 0.91; p = 0.0007; I2 = 40%), and sit-to-stand (STS) 60 score (mean difference, 3.74 repetitions; 2.35 to 5.14; p < 0.001; I2 = 0%). Intradialytic exercise alone, and protein supplementation alone, resulted in no statistically significant change in STS5 (−0.78 s; −1.86 to 0.30; p = 0.16; I2 = 0%), and STS30 (MD, 0.97 repetitions; −0.16 to 2.10; p = 0.09; I2 = 0%) performance, respectively. For secondary outcomes, L-carnitine and nandrolone-decanoate resulted in significant increases in muscle quantity in the dialysis population. Intradialytic exercise modifies measures of sarcopenia in the haemodialysis population; however, the majority of trials were low in quality. There is limited evidence for efficacious interventions in the peritoneal dialysis and transplant recipient populations.

Benchmarking CKD: incidence of CKD in a European country with low prevalence of chronic kidney disease and of kidney replacement therapy

Iceland was one of six European countries with an adjusted incidence of kidney replacement therapy (KRT) in 2018 lower than 100 per million persons (pmp), along with Estonia, Montenegro, Russia, Serbia and Finland. It was also one of 10 countries with an adjusted KRT prevalence <900 pmp. Furthermore, the prevalence of chronic kidney disease (CKD) in Iceland is up to 2.44-fold lower and the death rate from CKD up to 3.44-fold lower than in other countries with a low incidence of KRT, suggesting that the low KRT incidence actually reflects a low need for KRT rather than low uptake or availability of KRT. This identifies Iceland as a benchmark for countries trying to reduce KRT incidence. Iceland also represents one of the best genetically characterized populations in the world, facilitating studies on the influence of the genetic background versus environment and lifestyle on CKD. This issue of CKJ reports the incidence and risk factors for CKD in Icelandic adults. Diabetes, acute kidney injury, hypertension, cardiovascular disease, chronic lung disease, malignancy and major psychiatric illness were associated with an increased risk of incident CKD, as were obesity and sleep apnea in women. However, in 75% of incident CKD cases, CKD was first detected in category G3 or higher, emphasizing the need for new tools that allow an earlier diagnosis of CKD that precedes the loss of >50% of the functioning kidney mass and/or wider use of albuminuria as a screening tool. The European Society of Cardiology just recommended assessing albuminuria for routine cardiovascular risk workups for all.

Physical Exercise in People with Chronic Kidney Disease-Practices and Perception of the Knowledge of Health Professionals and Physical Activity and Sport Science Professionals about Their Prescription

There is evidence on the need to include physical exercise as a treatment for diseases. A large number of professionals are involved in this, but it is not known how physical exercise is prescribed and which professionals are involved. This research has two objectives: (a) to find out the current practices in Spain regarding the prescription of physical exercise in patients with Chronic Kidney Disease (CKD) and (b) to analyse the perception that different health and physical activity professionals have of their knowledge to prescribe of physical exercise in the treatment of CKD. This is an empirical research with an ex post facto retrospective analysis of the information in a descriptive and correlational way. A total of 692 health and sports professionals participated. A questionnaire validated by a committee of experts was administered. Descriptive analyses were carried out and the differences in the study variables were analysed using Chi-square tests and one-factor Analysis of Variance. From the results obtained, we conclude there is a need to develop specific training programmes in the field of physical exercise for health professionals, as well as the establishment of multiprofessional teams for the prescription of physical exercise in CKD treatment, including physical exercise professionals (Cafyde).

Frailty in kidney transplant candidates: a comparison between physical frailty phenotype and FRAIL scales

BACKGROUND

Frailty is common among advanced chronic kidney disease (CKD) patients who are kidney transplant (KT) candidates, and predisposes to poor outcomes after transplantation. However, frailty is not routinely measured during pretransplant work-up and it is unknown which metric should be used in this specific population. Our aim was to establish frailty prevalence in KT candidates according to different frailty scales.

METHODS

Prospective longitudinal study of 451 KT candidates evaluated for frailty by both Physical Frailty Phenotype (PFP) and FRAIL scale at the time of inclusion on the KT waiting list. Clinical and functional characteristics including sociodemographics, comorbidities, disability and nutritional status were recorded. Agreement between PFP and FRAIL scales as well as dissonant patients were analyzed.

RESULTS

Mean age was 60.9 years and 31.7% were female. Comorbidity burden among patients was high, with 36.9% and 16.2% presenting with diabetes and ischemic coronary disease, respectively. Disabilities were also frequent. More than 70% of patients presented with ≥ 1 PFP criteria while this percentage for ≥ 1 FRAIL criteria was 45.4%. Agreement between PFP and FRAIL was not good (kappa index 0.317). There were 132 patients who were pre-frail or frail according to PFP but non-frail according to the FRAIL scale and they presented with fewer comorbidities and less disability.

CONCLUSIONS

Frailty is frequent in advanced CKD patients, although its prevalence may vary according to different scales. Agreement between PFP and FRAIL scale is not good, and FRAIL scale might misclassify as robust patients those frail/prefrail patients who are in better health conditions.

OUP accepted manuscript

Sarcopaenia is a highly prevalent condition in persons on haemodialysis (HD). In stable very elderly (75–95 years old) persons on chronic HD, we prospectively studied the European Working Group on Sarcopaenia in Older People (EWGSOP2) steps stability over time in 37 controls and their response to a 12-week intradialytic lower limb exercise programme in 23 persons. Overall dropout was 15% and the main cause for dropout was death (8%). Thus 33 controls and 18 exercise participants were evaluated at 12 weeks. In controls, comorbidity, nutrition, dependency and frailty scales, anthropometric assessments, EWGSOP2 step values and the prevalence of suspected, confirmed and severe sarcopaenia as assessed by EWGSOP2 remained stable. In contrast, in persons who completed the exercise programme, a significant improvement in the five times sit-to-stand (STS-5) test was noted at the end of the 12-week exercise programme (19.2 ± 4.9–15.9 ± 5.9 seconds; P = .001), consistent with the lower limb nature of the exercise programme, that persisted 12 weeks after completion of the programme. Exercise also improved the Fried frailty scale (1.7 ± 1.0–1.1 ± 0.6; P = .004). In conclusion, EWGSOP2 steps remain stable in stable very elderly persons on HD and STS-5 is responsive to a short-term intradialytic lower limb exercise programme. These results may help define EWGSOP2-based primary endpoints in future large-scale clinical trials assessing exercise interventions.

Comparative Analysis on the Effects of Sarcopenia following Primary Total Knee Arthroplasty: A Retrospective Matched-Control Analysis

Despite the high incidence of sarcopenia in the orthopaedic community, studies evaluating the influence of sarcopenia following primary total knee arthroplasty (TKA) are limited. Therefore, the purpose of this study is to determine if sarcopenic patients undergoing primary TKA have higher rates of (1) in-hospital lengths of stay (LOS); (2) medical complications; (3) implant-related complications; (4) fall risk; (5) lower extremity fracture risk; and (6) costs of care. Sarcopenia patients were matched to controls in a 1:5 ratio according to age, sex, and medical comorbidities. The query yielded 90,438 patients with (n = 15,073) and without (n = 75,365) sarcopenia undergoing primary TKA. Primary outcomes analyzed included: in-hospital LOS, 90-day medical complications, 2-year implant-related complications, fall risk, lower extremity fracture risk, and costs of care. A p-value of less than 0.05 was considered statistically significant. Patients with sarcopenia undergoing primary TKA had greater in-hospital LOS (4 vs. 3 days, p < 0.0001). Sarcopenic patients were also found to have increased incidence and odds of 90-day medical complications (2.9 vs. 1.1%; odds ratio [OR] = 2.83, p < 0.0001), falls (0.9 vs. 0.3%; OR = 3.54, p < 0.0001), lower extremity fractures (1.0 vs. 0.2%; OR = 5.54, p < 0.0001), and reoperation (0.9 vs. 0.5%; OR = 1.87, p < 0.0001). Additionally, sarcopenic patients had greater 2-year implant-related complications (4.3 vs. 2.4%; OR = 1.80, p < 0.0001), as well as day of surgery ($52,900 vs. 48,248, p < 0.0001), and 90-day ($68,303 vs. $57,671, p < 0.0001) costs compared with controls. This analysis of over 90,000 patients demonstrates that patients with sarcopenia undergoing primary TKA have greater in-hospital LOS, increased odds of 90-day medical complications, falls, lower extremity fractures, and reoperations. Additionally, sarcopenia was associated with greater 2-year implant-related complications, day of surgery costs, and 90-day costs. The study is useful as it can allow orthopaedic surgeons to properly educate these patients of the potential complications which may occur following their surgery.

Prognostic interplay of kidney function with sarcopenia, anemia, disability and cognitive impairment. The GLISTEN study

BACKGROUND

Interactions between chronic kidney disease (CKD) and several comorbidities may potentially affect prognosis of older hospitalized patients. This study aims at evaluating the prognostic interactions between estimated glomerular filtration rate (eGFR), anemia, sarcopenia, functional and cognitive dysfunction, and 3-year mortality among older patients discharged from acute care hospitals.

METHODS

Our series consisted of 504 older adults enrolled in a multicenter observational study carried out in twelve Acute Geriatric and Internal Medicine wards throughout Italy. CKD was defined as an eGFR< 60 ml/min/1.73 m². Anemia, Short Portable Status Mental Questionnaire (SPMSQ), Basic Activities of Daily Living (BADL), sarcopenia, and Charlson index were considered in the analysis. 3-year survival was investigated by Cox regression and prognostic interactions among study variables were assessed by survival tree analysis. Accuracy of different survival models was investigated by C-index.

RESULTS

eGFR < 30 mL/min/1.73 m², anemia, sarcopenia, SPMSQ ≥ 5, and impairment in 1 or more BADL were significantly associated with mortality. Survival tree analysis showed that patients with eGFR < 35.32 ml/min/1.73 m² and SPMSQ ≥ 5 had the highest risk of mortality [hazard ratio (HR): 5.49, 95%CI: 3.04-9.94] followed by those with eGFR < 35.32 ml/min/1.73 m², hemoglobin < 11.95 g/dL and SPMSQ < 5 (HR:3.65; 95%CI: 2.21-6.02) and those with eGFR 35.32-47.99 ml/min/1.73 m² and sarcopenia (HR:3.65; 95%CI: 1.99-6.69). Survival tree leaf node membership had good accuracy in predicting the study outcome (C-index: 0.73, 95%CI:0.70-0.76).

CONCLUSIONS

Interactions among study risk factors designed distinct risk profiles in older patients discharged from acute care hospitals, that may help identify patients needing targeted interventions and appropriate follow-up after discharge.

Design and methodology of the chronic kidney disease as a dysmetabolic determinant of disability among older people (CKD-3D) study: a multicenter cohort observational study

Background

Chronic kidney disease (CKD) is a common condition in older people and represents a global health issue since it increases the risk of associated comorbidities and all-cause mortality. Furthermore, older people with reduced renal function might be at higher risk for developing functional limitation and disability. Moreover, the current creatinine-based measures of renal function are influenced by several factors in older population. The aims of the CKD-3D project are to perform an observational study to expand the knowledge about CKD-disability relationship and to investigate the use of novel biomarkers of kidney function.

Methods

An observational, multicenter, prospective cohort study will be conducted in 75 + old patients consecutively admitted to acute care wards of geriatric medicine at participating hospitals. The study planned to enroll 440 patients undergoing clinical and laboratory evaluations at baseline and after 12 months. Face-to-face follow-up at 6 months and telephone follow-up at 3 and 9 months will be carried out. Comprehensive Geriatric Assessment (CGA) and the measurement of Cystatin C, Beta-Trace Protein and Beta2-Microglobulin levels will be included.

Discussion

This study will provide useful information to prevent CKD-related disability by collecting real-life data over 1-year period. The combined approach of CGA and the investigation of innovative existing biomarkers will make it possible to develop new recommendations and guidelines for a patient-centered approach. It is believed that such a study may lead to an improvement of knowledge on CKD in elderly patients and may also have implications in daily clinical practice and in decision-making process.

Frailty in Pancreas Transplantation

There are a variety of definitions and criteria used in clinical practice to define frailty. In the absence of a gold-standard definition, frailty has been operationally defined as meeting 3 out of 5 phenotypic criteria indicating compromised function: low grip strength, low energy, slowed walking speed, low physical activity, and unintentional weight loss. Frailty is a common problem in solid organ transplant candidates who are in the process of being listed for a transplant, as well as after transplantation. Patients with diabetes or chronic kidney disease (CKD) are known to be at increased risk of being frail. As pancreas transplantation is exclusively performed among patients with diabetes and the majority of them also have CKD, pancreas transplant candidates and recipients are at high risk of being frail. Sarcopenia, fatigue, low walking speed, low physical activity, and unintentional weight loss, which are some of the phenotypes of frailty, are very prevalent in this population. In various solid organs, frail patients are less likely to be listed or transplanted and have high waitlist mortality. Even after a transplant, they have increased risk of prolonged hospitalization, readmission, and delayed graft function. Given the negative impact of frailty on solid organ transplants, we believe that frailty would have a similar or even worse impact on pancreas transplantation. Due to the paucity of data specifically among pancreas transplant recipients, here we include frailty data from patients with CKD, diabetes, and various solid organ transplant recipients.

Mitochondrial contributions to vascular endothelial dysfunction, arterial stiffness, and cardiovascular diseases

Cardiovascular disease (CVD) affects one in three adults and remains the leading cause of death in America. Advancing age is a major risk factor for CVD. Recent plateaus in CVD-related mortality rates in high-income countries after decades of decline highlight a critical need to identify novel therapeutic targets and strategies to mitigate and manage the risk of CVD development and progression. Vascular dysfunction, characterized by endothelial dysfunction and large elastic artery stiffening, is independently associated with an increased CVD risk and incidence and is therefore an attractive target for CVD prevention and management. Vascular mitochondria have emerged as an important player in maintaining vascular homeostasis. As such, age- and disease-related impairments in mitochondrial function contribute to vascular dysfunction and consequent increases in CVD risk. This review outlines the role of mitochondria in vascular function and discusses the ramifications of mitochondrial dysfunction on vascular health in the setting of age and disease. The adverse vascular consequences of increased mitochondrial-derived reactive oxygen species, impaired mitochondrial quality control, and defective mitochondrial calcium cycling are emphasized, in particular. Current evidence for both lifestyle and pharmaceutical mitochondrial-targeted strategies to improve vascular function is also presented.

Fighting the unbearable lightness of neglecting kidney health: the decade of the kidney

A brief comprehensive overview is provided of the elements constituting the burden of kidney disease [chronic kidney disease (CKD) and acute kidney injury]. This publication can be used for advocacy, emphasizing the importance and urgency of reducing this heavy and rapidly growing burden. Kidney diseases contribute to significant physical limitations, loss of quality of life, emotional and cognitive disorders, social isolation and premature death. CKD affects close to 100 million Europeans, with 300 million being at risk, and is projected to become the fifth cause of worldwide death by 2040. Kidney disease also imposes financial burdens, given the costs of accessing healthcare and inability to work. The extrapolated annual cost of all CKD is at least as high as that for cancer or diabetes. In addition, dialysis treatment of kidney diseases imposes environmental burdens by necessitating high energy and water consumption and producing plastic waste. Acute kidney injury is associated with further increases in global morbidity, mortality and economic burden. Yet investment in research for treatment of kidney disease lags behind that of other diseases. This publication is a call for European investment in research for kidney health. The innovations generated should mirror the successful European Union actions against cancer over the last 30 years. It is also a plea to nephrology professionals, patients and their families, caregivers and kidney health advocacy organizations to draw, during the Decade of the Kidney (2020–30), the attention of authorities to realize changes in understanding, research and treatment of kidney disease.

Sarcopenia and Mortality in Patients With Chronic Non-dialytic Renal Disease: Systematic Review and Meta-Analysis

OBJECTIVE

To analyze the results of prospective studies on the presence of sarcopenia and its association with cardiovascular events and mortality in patients with non-dialysis-dependent chronic renal disease.

METHODS

This study used the PRISMA protocol for systematic review. The systematic review and meta-analysis protocol was recorded in the prospective record of systematic reviews by PROSPERO International: CRD42019120391.

DATA SOURCES

MEDLINE via PubMed, Embase, Cochrane Library, CINAHL, Scopus, Web of Science and LILACS from December 2018 to April 20, 2019, with the survey results updated in January 2021.

DATA ANALYSIS

Random effect models were calculated to compare the results due to high heterogeneity identified.

RESULTS

The survey identified 951 studies. Of these, 392 were removed by duplicates and 559 references were selected for analysis. In the stage of evaluating titles and abstracts, 555 articles were excluded because they did not include inclusion criteria related to the population and study design, leaving 4 articles that were included in the systematic review and meta-analysis. A meta-analysis identified that the presence of sarcopenia increased the risk of mortality by 143%.

CONCLUSION(S)

The meta-analysis identified the influence of sarcopenia on mortality in non-dialysis-dependent chronic renal disease.

Muscle-Bone Crosstalk in Chronic Kidney Disease: The Potential Modulatory Effects of Exercise

Chronic kidney disease (CKD) is a prevalent worldwide public burden that increasingly compromises overall health as the disease progresses. Two of the most negatively affected tissues are bone and skeletal muscle, with CKD negatively impacting their structure, function and activity, impairing the quality of life of these patients and contributing to morbidity and mortality. Whereas skeletal health in this population has conventionally been associated with bone and mineral disorders, sarcopenia has been observed to impact skeletal muscle health in CKD. Indeed, bone and muscle tissues are linked anatomically and physiologically, and together regulate functional and metabolic mechanisms. With the initial crosstalk between the skeleton and muscle proposed to explain bone formation through muscle contraction, it is now understood that this communication occurs through the interaction of myokines and osteokines, with the skeletal muscle secretome playing a pivotal role in the regulation of bone activity. Regular exercise has been reported to be beneficial to overall health. Also, the positive regulatory effect that exercise has been proposed to have on bone and muscle anatomical, functional, and metabolic activity has led to the proposal of regular physical exercise as a therapeutic strategy for muscle and bone-related disorders. The detection of bone- and muscle-derived cytokine secretion following physical exercise has strengthened the idea of a cross communication between these organs. Hence, this review presents an overview of the impact of CKD in bone and skeletal muscle, and narrates how these tissues intrinsically communicate with each other, with focus on the potential effect of exercise in the modulation of this intercommunication.

New predictive equations to estimate resting energy expenditure of non-dialysis dependent chronic kidney disease patients

BACKGROUND

Determination of resting energy expenditure (REE) is an important step for the nutritional and medical care of patients with chronic kidney disease (CKD). Methods such as indirect calorimetry or traditional predictive equations are costly or inaccurate to estimate REE of CKD patients. We aimed to develop and validate predictive equations to estimate the REE of non-dialysis dependent-CKD patients.

METHODS

A database comprising REE measured by indirect calorimetry (mREE) of 170 non-dialysis dependent-CKD patients was used to develop (n = 119) and validate (n = 51) a new REE-predictive equation. Fat free mass (FFM) was assessed by anthropometry and by bioelectrical impedance (BIA).

RESULTS

The multiple regression analysis generated three equations: (1) REE (kcal/day) = 854 + 7.4*Weight + 179*Sex - 3.3*Age + 2.1 *eGFR + 26 (if DM) (R² = 0.424); (2) REE (kcal/day) = 678.3 + 14.07*FFM.ant + 54.8*Sex - 2*Age + 2.5*eGFR + 140.7* (if DM) (R² = 0.449); (3) REE (kcal/day) = 668 + 17.1*FFM.BIA - 2.7*Age - 92.7*Sex + 1.3*eGFR - 152.3 (if DM) (R² = 0.45). The estimated REE (eREE) was not different from the mREE (P = 0.181), a high ICC was found and the mean difference between mREE and eREE was not different from zero for the three equations in the validation group. eREE accuracy between 90 and 110% was observed in 55.3%, 62.5% and 61% of the patients for Eqs. (1), (2) and (3), respectively.

CONCLUSION

The equations showed acceptable accuracy for REE prediction making them a valuable tool to support practitioners to provide more reliable energy recommendations for this group of patients.

Uremic Sarcopenia and Its Possible Nutritional Approach

Uremic sarcopenia is a frequent condition present in chronic kidney disease (CKD) patients and is characterized by reduced muscle mass, muscle strength and physical performance. Uremic sarcopenia is related to an increased risk of hospitalization and all-causes mortality. This pathological condition is caused not only by advanced age but also by others factors typical of CKD patients such as metabolic acidosis, hemodialysis therapy, low-grade inflammatory status and inadequate protein-energy intake. Currently, treatments available to ameliorate uremic sarcopenia include nutritional therapy (oral nutritional supplement, inter/intradialytic parenteral nutrition, enteral nutrition, high protein and fiber diet and percutaneous endoscopic gastrectomy) and a personalized program of physical activity. The aim of this review is to analyze the possible benefits induced by nutritional therapy alone or in combination with a personalized program of physical activity, on onset and/or progression of uremic sarcopenia.

MicroRNA molecules as predictive biomarkers of adaptive responses to strength training and physical inactivity in haemodialysis patients

The miRNA-206 and miRNA-23a play an important role in muscle tissue hypertrophy, regeneration and atrophy. Both of these miRNAs have been highlighted as promising adaptation predictors; however, the available evidence on associations is inconclusive. Therefore, our aim was to assess the expression levels of these two miRNAs as predictors of change in muscle function during strength training and physical inactivity among dialysed patients. For this purpose, 46 haemodialysis patients were monitored for 12-weeks of either intradialytic strength training (EXG, n = 20) or physical inactivity during dialysis (CON, n = 26). In both groups of patients, we assessed the baseline expression levels of miRNA-23a and miRNA-206 and the isometric force generated during hip flexion (HF) contraction before and after the 12-week period. Among the EXG group, the expression of miRNA-206 predicted the change in HF (R² = 0.63, p = 0.0005) much more strongly than the expression of miRNA-23a (R² = 0.21, p = 0.027). Interestingly, baseline miRNA-23a (R² = 0.30, p = 0.006) predicted the change in HF much more than miRNA-206 (p = ns) among the CON group. Our study indicates that the baseline expression of miRNA-206 could predict the response to strength training, while miRNA-23a could serve as a potential predictive marker of functional changes during physical inactivity in dialysis patients.

Serum creatinine/cystatin C ratio as a case-finding tool for low handgrip strength in Chinese middle-aged and older adults

Measuring handgrip strength is the initial step to diagnose sarcopenia. To investigate whether the serum creatinine (Cr)/cystatin C (CysC) ratio could serve as a case-finding tool for low handgrip strength, we conducted a diagnostic accuracy study. Adults (aged ≥ 40 years) with normal renal function were recruited. Trained nurses collected blood samples and conducted the anthropometric measurements and handgrip strength test. The serum concentrations of Cr, CysC, and other biomarkers were measured. We recruited 1098 men and 1241 women. The Cr/CysC ratio was significantly associated with AWGS-defined low handgrip strength among men and women. The areas under the receiver operating characteristic curves were 0.79 among men and 0.78 among women for using the Cr/CysC ratio to identify AWGS-defined low handgrip strength. We set the Cr/CysC ratio cut-off values at < 8.9 among men and < 8.0 among women. The corresponding sensitivity values were 64.9% among men and 63.1% among women, while the specificity values were 83.7% among men and 77.5% among women. In conclusion, the Cr/CysC ratio is positively and linearly associated with handgrip strength and may be helpful for screening low handgrip strength in Chinese middle-aged and older adults dwelling in communities.

Aerobic exercise in adults with chronic kidney disease (CKD): a meta-analysis

PURPOSE

Patients with chronic kidney disease (CKD) are frail and have high risk of cardiovascular disease. This study was performed to assess the effects of aerobic exercise training in adults with CKD.

METHODS

MEDLINE, EMBASE, CENTRAL, Web of Science were searched up to December 2018 to identify eligible randomized controlled trials (RCTs) that studied aerobic exercise in adults with CKD. Primary outcomes include oxygen consumption at peak exercise (VO₂ peak), exercise capacity, blood pressure, heart rate, and health-related quality of life (HRQoL). Statistical analysis was performed using Review Manager 5.2.1 software.

RESULTS

Thirty-one trials, containing 1305 adults with CKD, were included. The most used aerobic exercise program was characterized as moderate intensity (15/31), 3 times/week frequency (22/31), 30 min duration (9/31) and 3 months follow-up (12/31). Significant improvement was observed in cardiorespiratory function (VO₂ peak) (P < 0.0001), exercise duration (P < 0.0001), HDL-C (P = 0.03) and pain (P = 0.007), physical role (P = 0.03), general health (P = 0.007) of HRQoL after aerobic exercise in patients with CKD. A marginal difference was observed in HR max (P = 0.07). However, no statistical difference was noticed in exercise capacity, blood pressure, resting heart rate, serum lipid and serum creatinine between aerobic training group and control. No subgroup differences were altered in all outcomes when studies were divided based on intensity of exercise training, the treatment of dialysis or the length of intervention.

CONCLUSIONS

Aerobic exercise training could benefit adult CKD patients in increasing cardiorespiratory function, exercise duration, HDL-C level and improve health quality of life.