Loop diuretics are associated with greater risk of sarcopenia in patients with non-dialysis-dependent chronic kidney disease

Changes in body composition and handgrip strength during dapagliflozin administration in patients with chronic kidney disease

Background

Dapagliflozin improves renal endpoints; however, concerns exist regarding safety in patients with chronic kidney disease. We examined the effects of dapagliflozin on body composition, handgrip strength, and sarcopenia.

Methods

This prospective observational study included 55 patients with chronic kidney disease (type 2 diabetes, n  = 27) treated with dapagliflozin 10 mg/day for 24 weeks. Handgrip strength, bio-impedance analysis-estimated skeletal muscle index, and extracellular water-to-total body water ratio were measured at baseline, 12 weeks, and 24 weeks after dapagliflozin administration. Sarcopenia was diagnosed as reduced handgrip strength (women: <18 kg; men: <28 kg) and decreased skeletal muscle index (women: <5.7 kg/m2; men: <7.0 kg/m2).

Results

During dapagliflozin therapy, skeletal muscle index significantly decreased from 7.51 ± 1.36 kg/m2 at baseline to 7.40 ± 1.28 kg/m2 at 12 weeks (P < 0.0001) and 7.32 ± 1.35 kg/m2 at 24 weeks (P < 0.0001). The extracellular water-to-total body water ratio decreased from 0.391 ± 0.012 at baseline to 0.390 ± 0.011 at 12 weeks (P = 0.17) and 0.389 ± 0.010 at 24 weeks (P = 0.002). Conversely, handgrip strength was unchanged from 32.9 ± 12.2 kg at baseline to 34.0 ± 12.1 kg at 12 weeks (P = 0.022) and 33.9 ± 12.4 kg at 24 weeks (P = 0.14). Sarcopenia prevalence did not change during dapagliflozin treatment [10.9% (n = 6) at baseline, 14.5% (n = 8) at 12 weeks, 10.9% (n = 6) at 24 weeks; P = 0.45.

Conclusions

During the 24-week dapagliflozin treatment, there was a decrease in skeletal muscle index and extracellular water-to-total body water ratio with unchanged handgrip strength in patients with chronic kidney disease. Sarcopenia prevalence remained constant. Therefore, regarding sarcopenia, short-term dapagliflozin administration might be safe. However, further long-term studies are required to determine the safety of dapagliflozin in these patients.

Effects of Medium Cut-Off Dialyzers on Fat Tissue and Muscle Mass Indices

BACKGROUND

Medium cut-off (MCO) dialyzers are designed to provide clearance of large-middle molecular weight uremic toxins and cytokines that are also responsible for the pathogenesis of sarcopenia.

AIM

To investigate the short- and long-term effects of MCO dialyzers on fat and muscle mass.

METHODS

This single-center prospective, cross-over study includes 20 maintenance hemodialysis (MHD) patients treated with low-flux (LF) dialyzers. Baseline parameters were measured under LF dialyzers and repeated at 2nd week and 6th month after switching to MCO dialyzers. Fat tissues were measured with a skinfold caliper and mid-upper arm circumference. Muscle thickness and strength parameters were measured with ultrasound and handgrip tests.

RESULTS

Median skinfold thickness showed a statistically significant increase in the second week of HD with MCO dialyzers [15 mm (10, 17) to 16 mm (13.3, 19.8), p = 0.04] and remained similar in the 6th month (p = 0.08). There was a gradual increase in median mid-upper arm circumference with a significant increase in the 6th month [28 (27, 29.5), 28.5 cm (27, 30), and 30.6 cm (26.7, 32), respectively, p = 0.03]. Significant increases were detected in the measurements of all four abdominal muscle groups (p = 0.03 for rectus abdominis and external oblique; p = 0.002 for internal oblique and transversus abdominis) in the 2nd week of MCO dialyzers and remained similar in the 6th month. Median RF and GCM thicknesses also significantly increased in the 2nd week (p = 0.001 and p < 0.001, respectively). The thicknesses of the external oblique, internal oblique, transversus abdominis, and rectus femoris muscles showed no significant differences in the 6th month. We also observed significant increases in the median GCM fibril length and GCM fibril pennation (p = 0.01 and p = 0.008, respectively) in the 2nd week, which also remained similar in the 6th month. The handgrip strength test showed a gradual increase at each time point without statistical significance.

CONCLUSION

MCO dialyzers provide increased fat and muscle mass, which might be due to their better clearance of uremic toxins compared to low-flux dialyzers. This study serves as a hypothesis-generating investigation; larger randomized controlled trials are required to validate the hypothesis.

Quality matters: chronic kidney disease progression is associated with reduced muscle strength independently of changes in skeletal muscle mass: an observational study

Background

Chronic kidney disease (CKD) is commonly associated with multifactorial neuromuscular impairments. Few studies have investigated CKD-induced changes in maximal voluntary force (MVF), and even fewer have longitudinal follow-up. The aim of this study is to investigate whether CKD progression modifies the relationship between skeletal muscle mass and force, and the prevalence of sarcopaenia and sarcopenic obesity.

Methods

The data used were prospectively collected during routine check-ups in a network of nutritional centres in Mexico and retrospectively analysed. From a dataset of 5430 patients, we selected 1098 patients with available anthropometric, kidney function, handgrip and bioimpedance data. The relationship between appendicular skeletal muscle mass (ASM) and MVF was investigated using mixed models and adjusted for age, sex, body mass index, physical activity level and CKD aetiology. Sarcopaenia prevalence were tested across period of follow-up using the Cochran-Mantel-Haenzen for repeated measures and across CKD stages using the Chi-2 test.

Results

After normalization with ASM, MVF was higher in CKD G1-G3 compared with G4 and G5 (P ≤ .001, Cohen's d = 0.270-0.576). Slopes between MVF and ASM were lower in CKD G3, G4 and G5 than in CKD G1-G2 [-2.268 (-3.927, -0.609), P  = .008; -2.694 (-4.593, -0.794), P  = .006; -3.675 (-5.326, -1.725), P  < .001, respectively]. The prevalence of sarcopaenia and sarcopaenic obesity did not differ across CKD stages, but recovery was most commonly observed in CKD G1-G2. Slope analysis showed an independent interaction between the slopes of kidney function and ASM on MVF evolution over time.

Conclusions

CKD negatively, progressively and independently affects the neuromuscular system, and force production is reduced for any given muscle mass as CKD progresses. While no association was found between CKD stage and prevalence of sarcopaenia, recovery was more frequent in the early CKD stages. These results suggest the importance of early rehabilitation programs to improve musculoskeletal health, quality of life and survival in CKD patients.

Depression and Quality of Life in Patients With Chronic Kidney Disease: A Mediation Analysis of Handgrip Strength and Demoralization

BACKGROUND

Chronic kidney disease (CKD) is a progressive disease impacting the physical function and mental health of sufferers. Depression is known to negatively impact quality of life, whereas handgrip strength and demoralization are important factors affecting physical and mental health. Lower handgrip strength has been associated with sarcopenia and higher risk of hospitalization in patients and higher workloads for nurse caregivers. Few studies have investigated the complex relations among these factors in patients with CKD.

PURPOSE

This study was designed to investigate the mediating effects of grip strength and demoralization on the relationship between depression and quality of life in patients with CKD.

METHODS

Two hundred fifty patients with CKD comprised the study sample. The hypotheses were tested using the PROCESS macro.

RESULTS

Depression was found to be negatively associated with handgrip strength and quality of life but positively associated with demoralization. The results indicate that both handgrip strength and demoralization mediate the association between depression and quality of life. Moreover, the results of multiple mediation model analysis showed handgrip strength and demoralization both play important roles in the link between depression and quality of life.

CONCLUSIONS

The results of this study indicate that handgrip strength and demoralization mediate the relationship between depression and quality of life in patients with CKD. Thus, increasing handgrip strength and decreasing demoralization levels may mitigate the impact of depression on quality of life. Therefore, nurses should better appreciate the importance of handgrip strength for patients with CKD and evaluate handgrip strength. Nurses should also develop physical and mental interventions to increase handgrip strength and decrease demoralization.

Sarcopenia in cirrhosis: From pathophysiology to interventional therapy

Sarcopenia, characterized by the loss of skeletal muscle mass and function, is a significant complication in patients with cirrhosis. This condition not only exacerbates the overall morbidity and mortality associated with liver disease but also complicates patient management, increasing the risk of hospitalization, infections, and hepatic encephalopathy. Despite its clinical significance, sarcopenia in cirrhotic patients remains underdiagnosed and undertreated. This review aims to summarize current knowledge on the pathophysiology of sarcopenia in cirrhosis, including mechanisms such as altered metabolism, hormonal imbalances, and inflammation. Additionally, we explore diagnostic challenges and discuss emerging therapeutic strategies, including nutritional support, exercise, and pharmacological interventions. By highlighting the gaps in existing research and proposing directions for future studies, this review seeks to improve the management and outcomes of cirrhotic patients affected by sarcopenia.

Disturbed carnitine metabolism is independently correlated with sarcopenia and prognosis in patients on hemodialysis

BACKGROUND & AIMS

Sarcopenia is frequent in hemodialysis patients and associated with an increased likelihood of adverse outcomes. Early identification of the risk of sarcopenia and effective intervention are of great importance for dialysis patients. However, little research has been carried out on potential biomarkers of sarcopenia in hemodialysis patients. The aim of this study was to investigate whether serum carnitine or acylcarnitine levels are biomarkers of sarcopenia in hemodialysis patients, and whether these are prognostic factors for occurrence of complications.

METHODS

This prospective clinical pilot study enrolled patients (n = 259) who were treated in the Blood Purification Center from May 2021 to July 2022, all participants were followed-up for 1- year. Serum carnintine and acylcarnitine (AC) were measured using our previously reported targeted liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The correlations between carnitine or acylcarnitine levels with sarcopenia and prognosis in patients were analysed.

RESULTS

The C0 (Free carnitine, FC) and total carnitine (TC) levels were significantly lower in the sarcopenia group than in the nonsarcopenia group [nonsarcopenia vs. sarcopenia: 20.97 (16.96, 25.83) vs. 17.77 (14.30, 22.78); p = 0.002] and [nonsarcopenia vs. sarcopenia: 30.12 (24.76, 36.62) vs. 26.03 (21.30, 32.01); p = 0.003]. Besides, significant difference between the groups were noted in low free carnitine (C0 < 20 μmol/L) patients (nonsarcopenia vs. sarcopenia: 72 (42.4%) vs. 56 (62.9%); p = 0.002) and high C2/C0 ratio (>0.4) patients (nonsarcopenia vs. sarcopenia: 36 (21.2%) vs. 30 (33.7%); p = 0.028). By multivariable analysis, the disturbed CM defined as C0 deficient and/or C2/C0 carnitine ratio abnormal rise was independently and significantly correlated with the prevalence of sarcopenia after adjusting for some confounding factors, such as age, gender and dialysis duration (P values for trend <0.05). Hemodialysis patients with sarcopenia [OR: 3.214 (1.307,7.904)] and disturbed CM [OR: 3.217 (1.112,9.305)] both had a 3-fold increased risk of falling and fracture after one year follow up. In addition, age and sarcopenia [OR: 2.883 (1.321, 6.289)] were independently and positively associated with incidence of Cardio- and cerebro-vascular events.

CONCLUSION

Disturbed carnitine metabolism is independently correlated with sarcopenia and prognosis in patients with hemodialysis. Serum carnitine level and C0/C2 ratio has the potential to be a simple, objective, and quick test for sarcopenia assessment whether such an intervention should be carried out for dialysis patients.

Accelerated aging of skeletal muscle and the immune system in patients with chronic liver disease

Patients with chronic liver disease (CLD) often present with significant frailty, sarcopenia, and impaired immune function. However, the mechanisms driving the development of these age-related phenotypes are not fully understood. To determine whether accelerated biological aging may play a role in CLD, epigenetic, transcriptomic, and phenotypic assessments were performed on the skeletal muscle tissue and immune cells of CLD patients and age-matched healthy controls. Accelerated biological aging of the skeletal muscle tissue of CLD patients was detected, as evidenced by an increase in epigenetic age compared with chronological age (mean +2.2 ± 4.8 years compared with healthy controls at -3.0 ± 3.2 years, p = 0.0001). Considering disease etiology, age acceleration was significantly greater in both the alcohol-related (ArLD) (p = 0.01) and nonalcoholic fatty liver disease (NAFLD) (p = 0.0026) subgroups than in the healthy control subgroup, with no age acceleration observed in the immune-mediated subgroup or healthy control subgroup (p = 0.3). The skeletal muscle transcriptome was also enriched for genes associated with cellular senescence. Similarly, blood cell epigenetic age was significantly greater than that in control individuals, as calculated using the PhenoAge (p < 0.0001), DunedinPACE (p < 0.0001), or Hannum (p = 0.01) epigenetic clocks, with no difference using the Horvath clock. Analysis of the IMM-Age score indicated a prematurely aged immune phenotype in CLD patients that was 2-fold greater than that observed in age-matched healthy controls (p < 0.0001). These findings suggested that accelerated cellular aging may contribute to a phenotype associated with advanced age in CLD patients. Therefore, therapeutic interventions to reduce biological aging in CLD patients may improve health outcomes.

Pharmacologic therapeutics in sarcopenia with chronic kidney disease

Inflammation, metabolic acidosis, renin-angiotensin system activation, insulin resistance, and impaired perfusion to skeletal muscles, among others, are possible causes of uremic sarcopenia. These conditions induce the activation of the nuclear factor-kappa B and mitogen-activated protein kinase pathways, adenosine triphosphate ubiquitin-proteasome system, and reactive oxygen species system, resulting in protein catabolism. Strategies for the prevention and treatment of sarcopenia in chronic kidney disease (CKD) are aerobic and resistance exercises along with nutritional interventions. Anabolic hormones have shown beneficial effects. Megestrol acetate increased weight, protein catabolic rate, and albumin concentration, and it increased intracellular water component and muscle mass. Vitamin D supplementation showed improvement in physical function, muscle strength, and muscle mass. Correction of metabolic acidosis showed an increase in protein intake, serum albumin levels, body weight, and mid-arm circumference. The kidney- gut-muscle axis indicates that dysbiosis and changes in gut-derived uremic toxins and short-chain fatty acids affect muscle mass, composition, strength, and functional capacity. Biotic supplements, AST-120 administration, hemodiafiltration, and preservation of residual renal function are alleged to reduce uremic toxins, including indoxyl sulfate (IS) and p-cresyl sulfate (PCS). Synbiotics reversed the microbiota change in CKD patients and decreased uremic toxins. AST-120 administration changed the overall gut microbiota composition in CKD. AST-120 prevented IS and PCS tissue accumulation, ameliorated muscle atrophy, improved exercise capacity and mitochondrial biogenesis, restored epithelial tight junction proteins, and reduced plasma endotoxin levels and markers of oxidative stress and inflammation. In a human study, the addition of AST-120 to standard treatment had modest beneficial effects on gait speed change and quality of life.

Drug-related sarcopenia as a secondary sarcopenia

Sarcopenia has a significant impact on falls, physical function, activities of daily living, and quality of life in older adults, and its prevention and treatment are becoming increasingly important as the global population ages. In addition to primary age-related sarcopenia, activity-related sarcopenia, disease-related sarcopenia, and nutrition-related sarcopenia have been proposed as secondary sarcopenia. Polypharmacy and potentially inappropriate medication based on multiple diseases cause health problems in older patients. In some cases, drugs used for therapeutic or preventive purposes act on skeletal muscle as adverse drug reactions and induce sarcopenia. Although sarcopenia caused by these adverse drug reactions may be more common in older patients, in particular those taking many medications, drug-related sarcopenia has not yet received much attention. This review summarizes drugs that may induce sarcopenia and emphasizes the importance of drug-related sarcopenia as a secondary sarcopenia. Geriatr Gerontol Int 2024; 24: 195-203.

Effect of osteosarcopenia on longitudinal mortality risk and chronic kidney disease progression in older adults

INTRODUCTION

Chronic kidney disease (CKD) causes a progressive loss of muscle and bone mass, which frequently overlap with and affect clinical outcomes. However, the impact of sarcopenia, low bone mineral density (BMD; osteopenia or osteoporosis), and osteosarcopenia (sarcopenia and low BMD) on CKD progression is yet to be determined. We aimed to address these issues in patients with CKD without kidney replacement therapy (KRT).

METHODS

This prospective cohort study included 251 outpatients aged ≥65 years with CKD without KRT enrolled in our hospital between June 2016 and March 2017. Sarcopenia was defined according to the 2014 criteria of the Asian Working Group for Sarcopenia (AWGS), and low BMD was defined as a T-score of ≤-1.0. The patients were divided into four groups: normal (no sarcopenia/normal BMD), only low BMD (no sarcopenia/low BMD), only sarcopenia (sarcopenia/normal BMD), and osteosarcopenia (sarcopenia/low BMD). The primary outcome was a composite of all-cause deaths, initiating KRT, and admissions owing to major adverse cardiovascular and cerebrovascular events (MACEs). The secondary outcome was a kidney composite outcome that included a 30 % reduction in creatinine-based estimated glomerular filtration rate (eGFR) and initiating KRT. The outcome risk was determined using the Cox regression models adjusted for potential confounders.

RESULTS

Median age (25th-75th percentile) and eGFR of the outpatients (35 % women) were 76 (69-81) years and 32.1 (20.8-41.7) ml/min/1.73 m2, respectively. During a median follow-up period of 5.2 years, there were 22 deaths, 117 30 % eGFR reductions, 48 KRTs, and 18 admissions owing to MACEs. The osteosarcopenia group rather than the only low BMD or only sarcopenia groups exhibited a higher risk of the primary (hazard ratio [HR]: 3.28, 95 % confidence interval [CI]: 1.52-7.08) and kidney composite (HR: 2.07, 95 % CI: 1.10-3.89) outcomes. Among the osteosarcopenia-related body compositions and physical functions, low handgrip strength (HGS) was strongly associated with a high risk of primary and kidney composite outcomes (HR: 2.44, 95 % CI: 1.46-4.08; HR: 1.48, 95 % CI: 0.97-2.24, respectively). The increase in HGS but not the body mass index, skeletal muscle mass index, or BMD was associated with lower risks of primary and kidney composite outcomes (HR: 0.93, 95 % CI: 0.89-0.98; HR: 0.96, 95 % CI: 0.92-0.99 per 1 kg, respectively).

CONCLUSIONS

Osteosarcopenia was associated with poor survival and kidney outcomes in older patients with CKD. Low HGS, which is common in patients with osteosarcopenia and CKD, was associated with increased mortality risk and kidney function decline. These findings can help the risk prediction and pathogenesis of the kidney-bone-muscle axis and improving muscle strength can help mitigate CKD progression.

Coexistence of sarcopenia and self-reported weight loss is a powerful predictor of mortality in older patients with heart failure

AIM

We examined whether the addition of self-reported weight loss improves the accuracy of prediction of mortality caused by sarcopenia in heart failure (HF) patients.

METHODS

We enrolled 477 HF patients (mean age 77 years) who received combined assessment of sarcopenia and self-reported weight loss. Sarcopenia was diagnosed according to the criteria of the Asian Working Group for Sarcopenia. If the patients answered "yes" to the question "have you lost 2 kg or more in the past 6 months?", they were diagnosed as having self-reported weight loss.

RESULTS

Sarcopenia and self-reported weight loss coexisted in 32% of patients. During a median follow-up period of 763 days, 65 patients (15%) died. Kaplan-Meier curves showed a significantly higher rate of mortality in HF patients with both sarcopenia and self-reported weight loss than in HF patients with sarcopenia alone. Multivariate Cox proportional hazards analysis showed that the coexistence of sarcopenia and self-reported weight loss is an independent predictor of mortality in HF patients. Inclusion of the coexistence of sarcopenia and self-reported weight loss in the baseline model consisting of established prognostic markers significantly improved both the net reclassification index and the integrated discrimination index.

CONCLUSIONS

The coexistence of sarcopenia and self-reported weight loss is a powerful predictor of mortality in HF patients. Geriatr Gerontol Int 2024; 24: 95-101.

Independent Link Between Use of Mineralocorticoid Receptor Antagonists and Muscle Wasting in Heart Failure Patients Not Receiving Renin-Angiotensin System Inhibitors

BACKGROUND

The renin-angiotensin system (RAS) activation is a proposed mechanism of muscle wasting (MW i.e., reduction in muscle mass). Although we reported that RAS inhibitors (RASIs) were associated with lower prevalence of MW in heart failure (HF) patients, the relationship between mineralocorticoid receptor (MR) signaling and MW has not been analyzed.

METHODS AND RESULTS

We analyzed data from 320 consecutive Japanese HF patients who underwent dual-energy X-ray absorptiometry scanning for assessment of appendicular skeletal muscle mass index (ASMI). In multiple linear regression analyses, plasma renin activity (PRA) was negatively correlated with ASMI in patients not receiving RASIs, indicating an untoward role of the RAS in MW. Results of analysis of covariance in which risk factors of MW served as covariates showed that use of MR antagonists (MRAs) was associated with lower ASMI and higher PRA in the non-RASIs group. The close relationship between use of MRAs and lower ASMI or higher PRA in the non-RASIs group was confirmed in analyses in which the differences in baseline characteristics between users and non-users of MRAs were minimized by using an inverse probability of treatment weighting.

CONCLUSIONS

Increased PRA by MR inhibition without concurrent RAS inhibition, possibly contributing to upregulation of angiotensin II signaling, may be associated with reduction in muscle mass.

Cross-Sectional Study on the Association between Dietary Patterns and Sarcopenia in Elderly Patients with Chronic Kidney Disease Receiving Conservative Treatment

Sarcopenia is a poor prognostic factor in patients with chronic kidney disease (CKD). Adequate dietary patterns are important for preventing sarcopenia; however, evidence regarding the underlying association between sarcopenia and diet is insufficient. Therefore, in this study, we aimed to investigate the association between sarcopenia and dietary patterns in CKD patients receiving conservative treatment. In this cross-sectional study, 441 patients with conservative CKD were examined using the Asian Working Group for Sarcopenia diagnostic criteria. CKD was defined as an eGFR of <60 mL/min/1.73 m2 present for >3 months. The participants were divided into sarcopenia and non-sarcopenia groups, and dietary patterns were compared between the two groups using the dietary variety score, a simple dietary survey method that investigates the weekly frequency of consumption of 10 food groups. Logistic regression analysis for CKD G3 showed that female sex (odds ratio (OR): 0.166, 95% confidence interval (CI): 0.086-0.320), increased body mass index (OR: 0.663, 95% CI: 0.590-0.745), and almost daily consumption of green/yellow vegetables (OR: 0.350, 95% CI: 0.176-0.695) were positively associated with non-sarcopenia. Although further prospective studies are required, the results suggest that low frequent consumption of vegetables is associated with sarcopenia in patients with CKD.

Association of the number of remaining teeth with kidney function in community-dwelling healthy older adults: a cross-sectional study

Objectives

Although a few studies have investigated the relationship between kidney and oral function (number of remaining teeth), their results remain inconclusive. Therefore, this study aimed to investigate the relationship between kidney function and oral health in community-dwelling healthy elderlies and examine the factors associated with kidney function.

Materials and Methods

We used cross-sectional data from the Shimane prefecture cohort recruited by the Center for Community-Based Health Research and Education in 2019. We collected clinical data on dental status, background factors and kidney function (estimated glomerular filtration rate [eGFR], mL/min/1.73 m2 and creatinine levels, mg/dL).

Results

The study enrolled 481 participants, whose mean age was 66.7±7.4 years, and 223 (46.4%) participants were men. Multivariate analysis revealed significant correlations between eGFR (B=0.17, P=0.04), creatinine (B=-0.54, P<0.01), and the number of remaining teeth. The number of remaining teeth was associated with creatinine and eGFR, which are indicators of kidney function.

Conclusion

This study suggests that preserving the teeth may prevent decline in kidney function. Dental professionals should provide instructions and professional care to reduce the risk of systemic diseases such as kidney dysfunction.

Independent Association Between Use of Proton Pump Inhibitors and Muscle Wasting in Patients with Heart Failure: A Single-Center, Ambispective, Observational Study

BACKGROUND

Although proton pump inhibitors (PPIs) play a pivotal role in the prevention and treatment of gastric acid-related diseases and gastrointestinal adverse events caused by antiplatelet therapies, the safety of long-term use of PPIs has been questioned.

OBJECTIVE

The aim of this study was to determine the effects of use of PPIs on muscle mass and bone mineral density in heart failure (HF) patients.

METHODS

This was a single-center, ambispective (combined retrospective and prospective), observational study. HF patients (n = 747; 72 years of age; males, 54%) who received a dual-energy x-ray absorptiometry scan were enrolled. Muscle wasting was defined as appendicular skeletal muscle mass index (ASMI) < 7.0 kg/m² in males and <5.4 kg/m² in females. Propensity scores for the use of PPIs were calculated using a multivariate logistic regression model to minimize selection bias.

RESULTS

Before propensity score matching, ASMI was significantly lower in patients receiving PPIs than in patients not receiving PPIs, resulting in a higher prevalence of muscle wasting in the PPI group. Such a relationship between use of PPIs and muscle wasting remained after propensity score matching. In multivariate Cox regression analyses, use of PPIs was independently associated with presence of muscle wasting (hazard ratio 1.68, 95% confidence interval 1.05-2.69) after adjustment for established risk factors of sarcopenia. On the other hand, there were no differences in bone mineral density between the PPI group and the no-PPI group.

CONCLUSION

Use of PPIs is associated with a high risk of muscle wasting in HF patients. Caution is warranted when long-term PPI treatment is performed in sarcopenic HF patients and HF patients with several risk factors for muscle wasting.

Circulating Extracellular Vesicle-Propagated microRNA Signature as a Vascular Calcification Factor in Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) accelerates vascular calcification via phenotypic switching of vascular smooth muscle cells (VSMCs). We investigated the roles of circulating small extracellular vesicles (sEVs) between the kidneys and VSMCs and uncovered relevant sEV-propagated microRNAs (miRNAs) and their biological signaling pathways.

METHODS AND RESULTS

We established CKD models in rats and mice by adenine-induced tubulointerstitial fibrosis. Cultures of A10 embryonic rat VSMCs showed increased calcification and transcription of osterix (Sp7), osteocalcin (Bglap), and osteopontin (Spp1) when treated with rat CKD serum. sEVs, but not sEV-depleted serum, accelerated calcification in VSMCs. Intraperitoneal administration of a neutral sphingomyelinase and biogenesis/release inhibitor of sEVs, GW4869 (2.5 mg/kg per 2 days), inhibited thoracic aortic calcification in CKD mice under a high-phosphorus diet. GW4869 induced a nearly full recovery of calcification and transcription of osteogenic marker genes. In CKD, the miRNA transcriptome of sEVs revealed a depletion of 4 miRNAs, miR-16-5p, miR-17~92 cluster-originated miR-17-5p/miR-20a-5p, and miR-106b-5p. Their expression decreased in sEVs from CKD patients as kidney function deteriorated. Transfection of VSMCs with each miRNA-mimic mitigated calcification. In silico analyses revealed VEGFA (vascular endothelial growth factor A) as a convergent target of these miRNAs. We found a 16-fold increase in VEGFA transcription in the thoracic aorta of CKD mice under a high-phosphorus diet, which GW4869 reversed. Inhibition of VEGFA-VEGFR2 signaling with sorafenib, fruquintinib, sunitinib, or VEGFR2-targeted siRNA mitigated calcification in VSMCs. Orally administered fruquintinib (2.5 mg/kg per day) for 4 weeks suppressed the transcription of osteogenic marker genes in the mouse aorta. The area under the curve of miR-16-5p, miR-17-5p, 20a-5p, and miR-106b-5p for the prediction of abdominal aortic calcification was 0.7630, 0.7704, 0.7407, and 0.7704, respectively.

CONCLUSIONS

The miRNA transcriptomic signature of circulating sEVs uncovered their pathologic role, devoid of the calcification-protective miRNAs that target VEGFA signaling in CKD-driven vascular calcification. These sEV-propagated miRNAs are potential biomarkers and therapeutic targets for vascular calcification.

The combination of phase angle and age has a good diagnostic value for sarcopenia in continuous ambulatory peritoneal dialysis patients

Aims

There are limited studies on phase angle and sarcopenia in continuous ambulatory peritoneal dialysis patients. So, we want to explore the association between phase angle and sarcopenia and find a more sensitive indicator for diagnosing sarcopenia.

Methods

We included 101 continuous ambulatory peritoneal dialysis patients from March 2022 to August 2022 and measured the phase angle and body composition by bioelectrical impedance analysis. All patients had their handgrip strength measured. Then, we divided patients into the sarcopenia (n = 30) group and non-sarcopenia (n = 71) group according to the sarcopenia diagnostic strategy formulated by the Asian Working Group for Sarcopenia. We used logistic regression to explore the risk factors of sarcopenia. We applied Receiver-operating characteristics curves to determine the diagnostic accuracy of these risk factors.

Results

After adjustments for sex, age, diabetes, BMI, extracellular water ratio, extra water, serum creatinine, total kt/v, and residual kt/v, phase angle correlated to handgrip strength and lowered limb muscle mass but not to skeletal muscle mass, upper arm muscle circumference, upper limb muscle mass and appendicular skeletal muscle mass index. In the multivariate logistic model, low phase angle and older age are risk factors for sarcopenia. The AUROC of phase angle for sarcopenia is 0.79 (95%CI, 0.70–0.86, P &lt; 0.01) for both sexes, 0.70 and 0.85 for females and males. After we combined age and phase angle as diagnostic indicators of sarcopenia, the AUROC is 0.91 (95%CI, 0.83–0.96, P &lt; 0.0001) in both sexes, 0.89 and 0.93 for females and males.

Conclusion

This study illustrates that age 52 or older is an independent risk factor for sarcopenia in continuous ambulatory peritoneal dialysis patients. Phase angle can act as a predictor of sarcopenia in those patients. But the combination of age and phase angle is more valuable in diagnosing sarcopenia.

The challenges of ascites management: An Indian perspective

Content available: Author Interview and Audio Recording.

A combined index of waist circumference and muscle quality is associated with cardiovascular disease risk factor accumulation in Japanese obese patients: a cross-sectional study

PURPOSE

To identify obese patients at high risk of cardiovascular disease (CVD) using a combined index of obesity and sarcopenia.

METHODS

In this cross-sectional study, we firstly conducted analysis of covariance to select each index most associated with the CVD risk score, the number of concomitant CVD risk factors, among obesity- (body mass index, percentage body fat, or waist circumference [WC]) and sarcopenia-evaluated indices (skeletal muscle mass index, handgrip strength, or muscle quality [MQ]), respectively in 188 Japanese obese patients (BMI ≥ 25 kg/m², 73 men and 115 women). Next, we conducted multivariate logistic regression analysis to compare the four groups (Group A-D) classified by medians of the selected indices.

RESULTS

WC and MQ were selected as the indices most associated with the CVD risk scores, respectively. The CVD risk score was significantly higher in Group B (low WC and low MQ) and Group D (high WC and low MQ) with higher prevalence of diabetes as compared with Group A (low WC and high MQ). Adjusted for sex and age, odds ratios for CVD risk scores = 2 were significantly higher in Group B, Group C (high WC and high MQ), and Group D compared with Group A. Furthermore, odds ratios for CVD risk scores = 3 were significantly higher only in Group D compared with Group A (4.29 [95% confidence interval: 1.49-12.33], p = 0.007).

CONCLUSION

Combined index of WC and MQ was useful in Japanese obese patients at high risk of CVD, regardless sex and age.

Sarcopenia in Non-Dialysis Chronic Kidney Disease Patients: Prevalence and Associated Factors

Background

Sarcopenia is related to morbidity and mortality in non-dialysis Chronic Kidney Disease (ND-CKD) patients; however, the pathophysiology of sarcopenia remains unclear. The study aimed to assess the prevalence and factors associated with sarcopenia in ND-CKD individuals.

Methods

We cross-sectionally evaluated 139 prevalent ND-CKD patients attending our outpatient clinic at Hospital das Clínicas of the Federal University of Pernambuco, between April and October 2019. Patients older than 18 years old and at G3-G5 CKD stages were included. Hand grip strength, Muscle Mass appendicular Index, and Gait Speed (GS) were defined by the standards of the European Working Group on Sarcopenia in Older People 2 guideline.

Results

Sarcopenia prevalence was 20.9% and severe sarcopenia 2.9%. Sarcopenic were mostly found in elderly ones (64.8 ± 13.5 years vs. 54.9 ± 12.8 years, p < 0.001), revealing lower body mass index [26.1 (6.8) vs. 28.6 (6.2), p = 0.023], lower phase angle (PhA) [4.50 (1.10) vs. 5.60 (1.20), p < 0.001] and lower GS [1.00 (0.50) vs. 1.40 (0.4), p < 0.001]. They also presented lower serum creatinine levels [2.40 (1.50) vs. 3.0 (1.8), p = 0.032], lower Albumin-to-Creatinine Ratio [72.60 (1008.30) vs. 342.30 (1172.1), p = 0.039] and Hemoglobin levels [11.45 (1.8) vs. 12.60 (2.40), p = 0.003], and higher levels of C-reactive protein [0.2 (0.80) vs. 0.03 (0.3), p = 0.045] compared to non-sarcopenic. Under Poisson Multivariate Model, PhA [Relative precision (RP): 0.364, Confidence Interval (CI) (95%):0.259-0.511, p < 0.001], Interleukin six (IL-6) [RP: 1.006, CI (95%):1.001-1.01, p = 0.02] and serum creatinine levels [RP: 0.788, CI (95%): 0.641-0.969, p = 0.024] were associated with sarcopenia.

Conclusions

Sarcopenia predominance was identified in our ND-CKD population, and was associated with lower PhA values, higher IL-6 levels, and lower serum creatinine levels.

Factors affecting health-related quality of life in older patients with chronic kidney disease: a single-center cross-sectional study

BACKGROUND

Health-related quality of life (HRQoL) assessment is important for patients with chronic kidney disease (CKD). However, few studies have examined factors related to HRQoL, such as physical function, in older patients with predialysis CKD. This study evaluated the relationship between physical function, renal function, and nutritional status on the HRQoL in this patient group.

METHODS

This cross-sectional study included 61 patients aged ≥ 65 years with stages 3-5 predialysis CKD who were admitted for CKD education purposes. Using the EuroQoL 5-dimension 5-level (EQ-5D-5L) health status measure, the percentages of each EQ-5D-5L item were investigated. Physical function was measured using the short physical performance battery (SPPB) and grip strength, and characteristics, such as age, sex, diabetes mellitus, estimated glomerular filtration rate, and Geriatric Nutrition Risk Index, were investigated. Factors associated with EQ-5D-5L were identified using multiple regression analysis.

RESULTS

More than half of respondents (34/61, 55.7%) selected the second or higher level "have a problem" for the pain/discomfort section. The EQ-5D-5L score was significantly correlated with grip strength (r = 0.34, p = 0.01) and SPPB (r = 0.59, p = 0.00) in a single correlation analysis. Only SPPB (β = 0.67, p = 0.00) remained a significant factor after adjustment for grip strength, SPPB, age, sex, diabetes mellitus, and estimated glomerular filtration rate.

CONCLUSION

Physical function may be an important factor influencing HRQoL in older patients with predialysis CKD.

Sarcopenia and polypharmacy among older adults: A scoping review of the literature

BACKGROUND

Sarcopenia and polypharmacy are both prevalent conditions in the geriatric population, leading to poor quality of life and adverse outcomes.

OBJECTIVE

To explore the evidence on the relationship between sarcopenia and polypharmacy and to summarize the findings and the gaps from the existing literature.

METHOD

A systematic scoping review was conducted between March and May 2021, with no restriction on publication date, using the Arksey and O'Malley framework and reported according to PRISMA-ScR. Four bibliographic databases, PubMed, Web of Science, Scopus, Proquest One Academic, and four sources of gray literature were searched for studies written in English or Greek. Data were extracted quantitatively and using thematic analysis.

RESULTS

Of the 397 initially retrieved records, 22 studies were finally included in this review, 20 published articles and 2 posters-presentations. Most of the studies used cross-sectional data. The relationship between sarcopenia and polypharmacy should be interpreted on the basis of the definition of polypharmacy, the diagnostic criteria of sarcopenia used, and the population setting. Sarcopenia or risk for sarcopenia are associated with polypharmacy or the number of medications in community-dwelling older adults, regardless of diagnostic criteria used for sarcopenia.

CONCLUSION

There is an association between sarcopenia or risk for sarcopenia and polypharmacy or the number of medications in community-dwelling older adults but not among residents of nursing homes or inpatients. Specific widely accepted definitions of polypharmacy and sarcopenia, a consensus on the method of sarcopenia assessment, and prospective studies are needed to identify polypharmacy as a potential risk factor for sarcopenia.

Sarcopenia in Chronic Kidney Disease: A Scoping Review of Prevalence, Risk Factors, Association with Outcomes, and Treatment

Sarcopenia, a condition characterized by loss of skeletal muscle mass and function, has important clinical ramifications. We aimed to map the existing literature about prevalence, risk factors, associated adverse outcomes, and treatment of sarcopenia in individuals with chronic kidney disease (CKD). A scoping review of the literature was conducted to identify relevant articles published from databases' inception to September 2019. Individuals with CKD, regardless of their disease stage and their comorbidities, were included. Only studies with sarcopenia diagnosed using both muscle mass and function, based on published consensus definitions, were included. For studies on treatment, only randomized controlled trials with at least one sarcopenia parameter as an outcome were included. Our search yielded 1318 articles, of which 60 from were eligible for this review. The prevalence of sarcopenia ranged from 4 to 42% according to the definition used, population studied, and the disease stage. Several risk factors for sarcopenia were identified including age, male gender, low BMI, malnutrition, and high inflammatory status. Sarcopenia was found to be associated with several adverse outcomes, including disabilities, hospitalizations, and mortality. In CKD subjects, several therapeutic interventions have been assessed in randomized controlled trial with a muscle mass, strength, or function endpoint, however, studies focusing on sarcopenic CKD individuals are lacking. The key interventions in the prevention and treatment of sarcopenia in CKD seem to be aerobic and resistance exercises along with nutritional interventions. Whether these interventions are effective to treat sarcopenia and prevent clinical consequences in this population remains to be fully determined.

Current status of the assessment of sarcopenia, frailty, physical performance and functional status in chronic kidney disease patients

PURPOSE OF REVIEW

Low physical function, frailty, and sarcopenia are common complications of chronic kidney disease (CKD). In this article, we review the epidemiology and pathogenesis of low physical function, as well as its associations with adverse outcomes in CKD patients. Additionally, we present various traditional and novel methods for assessment of physical function in CKD patients.

RECENT FINDINGS

In nondialysis dependent (NDD) and dialysis-dependent CKD patients, the prevalence of low physical function, frailty, and sarcopenia are substantially higher than in the general population. The potential mechanisms of low physical function, frailty, and sarcopenia in CKD patients are due to various factors including underlying kidney disease, co-existing comorbidities, and certain therapeutic interventions utilized in CKD. Increasing evidence has also uncovered the ill effects of impaired physical function on clinical outcomes in CKD patients.

SUMMARY

Routine assessment of physical function is an under-utilized yet important component in the management of CKD patients. Future studies are needed to determine how prescription of exercise and increased daily physical activity can be tailored to optimize the health and well-being of NDD and dialysis-dependent CKD patients in pursuit of successful aging.

Relationship Between Sarcopenia and Cardiovascular Diseases in the Elderly: An Overview

With the advent of population aging, aging-related diseases have become a challenge for governments worldwide. Sarcopenia has defined as a clinical syndrome associated with age-related loss such as skeletal muscle mass, strength, function, and physical performance. It is commonly seen in elderly patients with chronic diseases. Changes in lean mass are common critical determinants in the pathophysiology and progression of cardiovascular diseases (CVDs). Sarcopenia may be one of the most important causes of poor physical function and decreased cardiopulmonary function in elderly patients with CVDs. Sarcopenia may induce CVDs through common pathogenic pathways such as malnutrition, physical inactivity, insulin resistance, inflammation; these mechanisms interact. In this study, we aimed to investigate the relationship between sarcopenia and CVDs in the elderly. Further research is urgently needed to understand better the relationship, pathophysiology, clinical presentation, diagnostic criteria, and mechanisms of sarcopenia and CVDs, which may shed light on potential interventions to improve clinical outcomes and provide greater insight into the disorders above.

Angiotensin II inhibition: a potential treatment to slow the progression of sarcopenia

Sarcopenia is defined as the progressive and generalized loss of skeletal muscle mass and strength, which is associated with increased likelihood of adverse outcomes including falls, fractures, physical disability, and mortality. The etiology of sarcopenia has been postulated to be multifactorial with genetics, aging, immobility, nutritional deficiencies, inflammation, stress, and endocrine factors all contributing to the imbalance of muscle anabolism and catabolism. The prevalence of sarcopenia is estimated to range from 13 to 24% in adults over 60 years of age and up to 50% in persons aged 80 and older. As the population continues to age, the prevalence of sarcopenia continues to increase and is expected to affect 500 million people by the year 2050. Sarcopenia impacts the overall health of patients through limitations in functional status, increase in hospital readmissions, poorer hospital outcomes, and increase in overall mortality. Thus, there exists a need to prevent or reduce the occurrence of sarcopenia. Here, we explore the potential mechanisms and current studies regarding angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors on reducing the development of sarcopenia through the associated changes in cardiovascular function, renal function, muscle fiber composition, inflammation, endothelial dysfunction, metabolic efficiency, and mitochondrial function.

The Contribution of Plasma Urea to Total Osmolality During Iatrogenic Fluid Reduction in Critically Ill Patients

Hyperosmolality is common in critically ill patients during body fluid volume reduction. It is unknown whether this is only a result of decreased total body water or an active osmole-producing mechanism similar to that found in aestivating animals, where muscle degradation increases urea levels to preserve water. We hypothesized that fluid volume reduction in critically ill patients contributes to a shift from ionic to organic osmolytes similar to mechanisms of aestivation. We performed a post-hoc analysis on data from a multicenter observational study in adult intensive care unit (ICU) patients in the postresuscitative phase. Fluid, electrolyte, energy and nitrogen intake, fluid loss, estimated glomerular filtration rate (eGFR), and estimated plasma osmolality (eOSM) were registered. Contributions of osmolytes Na⁺, K⁺, urea, and glucose to eOSM expressed as proportions of eOSM were calculated. A total of 241 patients were included. eOSM increased (median change 7.4 mOsm/kg [IQR-1.9-18]) during the study. Sodium's and potassium's proportions of eOSM decreased (P < .05 and P < .01, respectively), whereas urea's proportion increased (P < .001). The urea's proportion of eOSM was higher in patients with negative vs. positive fluid balance. Urea's proportion of eOSM increased with eOSM (r = 0.63; adjusted for eGFR r = 0.80), but not nitrogen intake. In patients without furosemide and/or renal replacement therapy (n = 17), urea's proportion of eOSM and eOSM correlated strongly (r = 0.92). Urea's proportion of eOSM was higher in patients not surviving up to 90 d. In stabilized ICU patients, the contribution of urea to plasma osmolality increased during body water volume reduction, statistically independently of nitrogen administration and eGFR. The shift from ionic osmolytes to urea during body fluid volume reduction is similar to that seen in aestivating animals. ClinicalTrials.org Identifier: NCT03972475.

Association of Serum Phosphate with Low Handgrip Strength in Patients with Advanced Chronic Kidney Disease

Muscle wasting and hyperphosphatemia are becoming increasingly prevalent in patients who exhibit a progressive decline in kidney function. However, the association between serum phosphate (Pi) level and sarcopenia in advanced chronic kidney disease (CKD) patients remains unclear. We compared the serum Pi levels between advanced CKD patients with (n = 51) and those without sarcopenia indicators (n = 83). Low appendicular skeletal muscle mass index (ASMI), low handgrip strength, and low gait speed were defined per the standards of the Asian Working Group for Sarcopenia. Mean serum Pi level was significantly higher in advanced CKD patients with sarcopenia indicators than those without sarcopenia indicators (3.88 ± 0.86 vs. 3.54 ± 0.73 mg/dL; p = 0.016). Univariate analysis indicated that serum Pi was negatively correlated with ASMI, handgrip strength, and gait speed. Multivariable analysis revealed that serum Pi was significantly associated with handgrip strength (standardized β = -0.168; p = 0.022) and this association persisted even after adjustments for potential confounders. The optimal serum Pi cutoff for predicting low handgrip strength was 3.65 mg/dL, with a sensitivity of 82.1% and specificity of 56.6%. In summary, low handgrip strength is common in advanced CKD patients and serum Pi level is negatively associated with handgrip strength.

Maintenance of Skeletal Muscle to Counteract Sarcopenia in Patients with Advanced Chronic Kidney Disease and Especially Those Undergoing Hemodialysis

Life extension in modern society has introduced new concepts regarding such disorders as frailty and sarcopenia, which has been recognized in various studies. At the same time, cutting-edge technology methods, e.g., renal replacement therapy for conditions such as hemodialysis (HD), have made it possible to protect patients from advanced lethal chronic kidney disease (CKD). Loss of muscle and fat mass, termed protein energy wasting (PEW), has been recognized as prognostic factor and, along with the increasing rate of HD introduction in elderly individuals in Japan, appropriate countermeasures are necessary. Although their origins differ, frailty, sarcopenia, and PEW share common components, among which skeletal muscle plays a central role in their etiologies. The nearest concept may be sarcopenia, for which diagnosis techniques have recently been reported. The focus of this review is on maintenance of skeletal muscle against aging and CKD/HD, based on muscle physiology and pathology. Clinically relevant and topical factors related to muscle wasting including sarcopenia, such as vitamin D, myostatin, insulin (related to diabetes), insulin-like growth factor I, mitochondria, and physical inactivity, are discussed. Findings presented thus far indicate that in addition to modulation of the aforementioned factors, exercise combined with nutritional supplementation may be a useful approach to overcome muscle wasting and sarcopenia in elderly patients undergoing HD treatments.

β2-adrenergic receptor agonist counteracts skeletal muscle atrophy and oxidative stress in uremic mice

In patients with chronic kidney disease, skeletal muscle dysfunction is associated with mortality. Uremic sarcopenia is caused by ageing, malnutrition, and chronic inflammation, but the molecular mechanism and potential therapeutics have not been fully elucidated yet. We hypothesize that accumulated uremic toxins might exert a direct deteriorative effect on skeletal muscle and explore the pharmacological treatment in experimental animal and culture cell models. The mice intraperitoneally injected with indoxyl sulfate (IS) after unilateral nephrectomy displayed an elevation of IS concentration in skeletal muscle and a reduction of instantaneous muscle strength, along with the predominant loss of fast-twitch myofibers and intramuscular reactive oxygen species (ROS) generation. The addition of IS in the culture media decreased the size of fully differentiated mouse C2C12 myotubes as well. ROS accumulation and mitochondrial dysfunction were also noted. Next, the effect of the β2-adrenergic receptor (β2-AR) agonist, clenbuterol, was evaluated as a potential treatment for uremic sarcopenia. In mice injected with IS, clenbuterol treatment increased the muscle mass and restored the tissue ROS level but failed to improve muscle weakness. In C2C12 myotubes stimulated with IS, although β2-AR activation also attenuated myotube size reduction and ROS accumulation as did other anti-oxidant reagents, it failed to augment the mitochondrial membrane potential. In conclusion, IS provokes muscular strength loss (uremic dynapenia), ROS generation, and mitochondrial impairment. Although the β2-AR agonist can increase the muscular mass with ROS reduction, development of therapeutic interventions for restoring skeletal muscle function is still awaited.

Optimal Protein Intake in Pre-Dialysis Chronic Kidney Disease Patients with Sarcopenia: An Overview

Multi-factors, such as anorexia, activation of renin-angiotensin system, inflammation, and metabolic acidosis, contribute to malnutrition in chronic kidney disease (CKD) patients. Most of these factors, contributing to the progression of malnutrition, worsen as CKD progresses. Protein restriction, used as a treatment for CKD, can reduce the risk of CKD progression, but may worsen the sarcopenia, a syndrome characterized by a progressive and systemic loss of muscle mass and strength. The concomitant rate of sarcopenia is higher in CKD patients than in the general population. Sarcopenia is also associated with mortality risk in CKD patients. Thus, it is important to determine whether protein restriction should be continued or loosened in CKD patients with sarcopenia. We may prioritize protein restriction in CKD patients with a high risk of end-stage kidney disease (ESKD), classified to stage G4 to G5, but may loosen protein restriction in ESKD-low risk CKD stage G3 patients with proteinuria <0.5 g/day, and rate of eGFR decline <3.0 mL/min/1.73 m²/year. However, the effect of increasing protein intake alone without exercise therapy may be limited in CKD patients with sarcopenia. The combination of exercise therapy and increased protein intake is effective in improving muscle mass and strength in CKD patients with sarcopenia. In the case of loosening protein restriction, it is safe to avoid protein intake of more than 1.5 g/kgBW/day. In CKD patients with high risk in ESKD, 0.8 g/kgBW/day may be a critical point of protein intake.

Modern trends in diuretics development

Diuretics are the first-line therapy for widespread cardiovascular and non-cardiovascular diseases. Traditional diuretics are commonly prescribed for treatment in patients with hypertension, edema and heart failure, as well as with a number of kidney problems. They are diseases with high mortality, and the number of patients suffering from heart and kidney diseases is increasing year by year. The use of several classes of diuretics currently available for clinical use exhibits an overall favorable risk/benefit balance. However, they are not devoid of side effects. Hence, pharmaceutical researchers have been making efforts to develop new drugs with a better pharmacological profile. High-throughput screening, progress in protein structure analysis and modern methods of chemical modification have opened good possibilities for identification of new promising agents for preclinical and clinical testing. In this review, we provide an overview of the medicinal chemistry approaches toward the development of small molecule compounds showing diuretic activity that have been discovered over the past decade and are interesting drug candidates. We have discussed promising natriuretics/aquaretics/osmotic diuretics from such classes as: vasopressin receptor antagonists, SGLT2 inhibitors, urea transporters inhibitors, aquaporin antagonists, adenosine receptor antagonists, natriuretic peptide receptor agonists, ROMK inhibitors, WNK-SPAK inhibitors, and pendrin inhibitors.

Antihypertensive Treatment in Kidney Transplant Recipients-A Current Single Center Experience

Arterial hypertension affects the survival of the kidney graft and the cardiovascular morbidity and mortality of the recipient after kidney transplantation (KTx). Thus, antihypertensive treatment is necessary for a vast majority of these patients. Long-term data on antihypertensive drugs and their effects on allograft function after KTx is still limited, and further investigation is required. We retrospectively analyzed a cohort of 854 recipients who received a kidney transplant at our transplant center between 2007 and 2015 with regard to antihypertensive treatment and its influence on graft function and survival. 1-y after KTx, 95.3% patients were treated with antihypertensive therapy. Of these, 38.6% received mono- or dual-drug therapy, 38.0% received three to four drugs and 8.1% were on a regimen of ≥5 drugs. Beta-blockers were the most frequently used antihypertensive agents (68.1%). Neither the use of angiotensin-converting enzyme inhibitor/angiotensin receptor blockers (51.9%) and calcium channel blockers (51.5%), nor the use the use of loop diuretics (38.7%) affected allograft survival. Arterial hypertension and the number of antihypertensive agents were associated with unfavorable allograft outcomes (each p < 0.001). In addition to the well-known risk factors of cold ischemic time and acute rejection episodes, the number of antihypertensive drugs after one year, which reflects the severity of hypertension, is a strong predictor of unfavorable allograft survival.

Sarcopenia in chronic kidney disease: what have we learned so far?

The term sarcopenia was first introduced in 1988 by Irwin Rosenberg to define a condition of muscle loss that occurs in the elderly. Since then, a broader definition comprising not only loss of muscle mass, but also loss of muscle strength and low physical performance due to ageing or other conditions, was developed and published in consensus papers from geriatric societies. Sarcopenia was proposed to be diagnosed based on operational criteria using two components of muscle abnormalities, low muscle mass and low muscle function. This brought awareness of an important nutritional derangement with adverse outcomes for the overall health. In parallel, many studies in patients with chronic kidney disease (CKD) have shown that sarcopenia is a prevalent condition, mainly among patients with end stage kidney disease (ESKD) on hemodialysis (HD). In CKD, sarcopenia is not necessarily age-related as it occurs as a result of the accelerated protein catabolism from the disease and from the dialysis procedure per se combined with low energy and protein intakes. Observational studies showed that sarcopenia and especially low muscle strength is associated with worse clinical outcomes, including worse quality of life (QoL) and higher hospitalization and mortality rates. This review aims to discuss the differences in conceptual definition of sarcopenia in the elderly and in CKD, as well as to describe etiology of sarcopenia, prevalence, outcome, and interventions that attempted to reverse the loss of muscle mass, strength and mobility in CKD and ESKD patients.

Uremic Sarcopenia: Clinical Evidence and Basic Experimental Approach

Sustained physical activity extends healthy life years while a lower activity due to sarcopenia can reduce them. Sarcopenia is defined as a decrease in skeletal muscle mass and strength due not only to aging, but also from a variety of debilitating chronic illnesses such as cancer and heart failure. Patients with chronic kidney disease (CKD), who tend to be cachexic and in frail health, may develop uremic sarcopenia or uremic myopathy due to an imbalance between muscle protein synthesis and catabolism. Here, we review clinical evidence indicating reduced physical activity as renal function deteriorates and explore evidence-supported therapeutic options focusing on nutrition and physical training. In addition, although sarcopenia is a clinical concept and difficult to recapitulate in basic research, several in vivo approaches have been attempted, such as rodent subtotal nephrectomy representing both renal dysfunction and muscle weakness. This review highlights molecular mechanisms and promising interventions for uremic sarcopenia that were revealed through basic research. Extensive study is still needed to cast light on the many aspects of locomotive organ impairments in CKD and explore the ways that diet and exercise therapies can improve both outcomes and quality of life at every level.

Negative Inotropic Effect of BGP-15 on the Human Right Atrial Myocardium

Cardiovascular morbidity and mortality carry great socioeconomic burden worldwide that mandates the development of new, efficacious therapeutic agents with limited adverse effects. O-(3-piperidino-2-hydroxy-1-propyl) nicotinic acid amidoxime (BGP-15) is a known, well-tolerable drug candidate that exerts beneficial effects in several disease models. As BGP-15 has a significant structural similarity with propranolol, it arose that BGP-15 might also have a direct effect on the heart. Thus, in the present work, we investigated the effect of BGP-15 and propranolol on the contractility of isolated, paced, human right atrial samples (obtained from patients undergone open-heart surgery), with or without previous isoproterenol (ISO) stimulation (evoking an indirect or direct effect, respectively). We found that both BGP-15 and propranolol exerted direct as well as indirect negative inotropic effects on the atrial myocardium, reaching similar maximal response. However, BGP-15 had considerably smaller potency than propranolol regarding both types of negative inotropy. In addition, BGP-15, in contrast to propranolol, had a significantly greater indirect negative inotropic effect on samples exhibiting strong response to ISO. Moreover, the indirect negative inotropic effect of BGP-15 was significantly greater on samples derived from diabetic patients than on samples obtained from non-diabetic ones. Our results suggest that the enhanced ISO sensitivity is associated with the diabetic state, and BGP-15 exerts greater negative inotropic effect on the human atrial myocardium in both conditions (as compared to the atrial tissue that is not ISO oversensitive and/or diabetic). Additionally, the negative inotropic effects of BGP-15 and propranolol seem to be mediated by in part different molecular pathways in the atrial myocardium.

Management of refractory ascites attenuates muscle mass reduction and improves survival in patients with decompensated cirrhosis

BACKGROUND

This study investigated time-course changes in skeletal muscle volume per year with tolvaptan in patients with refractory ascites that was unresponsive to loop diuretics and aldosterone antagonists.

METHODS

This retrospective study included 42 patients who received tolvaptan for refractory ascites and/or hepatic edema and underwent computed tomography (CT) before and ≥ 3 months after initiating tolvaptan. The time-course changes in skeletal muscle index per year [ΔSMI (%)] was calculated as follows: ΔSMI (%) = (SMI at final CT scan - SMI at initial CT scan)/SMI at initial CT scan × 100/years between CT scans.

RESULTS

Eligible patients were 23 men and 19 women of median age of 71 years (range 21-94 years). The median follow-up period was 22.7 (range 3.5-54.6) months. ΔSMI (%) was significantly higher in the responders group than in the nonresponder group. Multivariate analysis showed the response to tolvaptan was an independent and significant factor associated with an increase in muscle mass [odds ratio (OR) 20.364; 95% CI 2.327-178.97; P = 0.006]. Overall survival with tolvaptan was significantly higher in the responder group than in the nonresponder group. Multivariate analysis showed that the response to tolvaptan treatment was a significant contributor to good prognosis (OR 3.884; 95% CI 1.264-11.931; P = 0.018). A significant negative correlation was observed between the dosage of furosemide and ΔSMI (%) (P = 0.014).

CONCLUSIONS

Treatment of refractory ascites with tolvaptan may attenuate the progression of sarcopenia and improve the prognosis in patients with decompensated cirrhosis.

Loop diuretic use is associated with skeletal muscle wasting in patients with heart failure

BACKGROUND

Loop diuretics are widely used for the management of fluid retention in patients with heart failure (HF). Sarcopenia, defined as decreased skeletal muscle mass, is frequently present in patients with HF and is associated with poor prognosis. The effects of loop diuretics on skeletal muscle in HF patients have not been fully elucidated. Here, we investigated the impact of loop diuretics on the skeletal muscle mass in patients with HF.

METHODS

We conducted a subanalysis of a cross-sectional study from 10 hospitals evaluating 155 patients with HF (age 67 ± 13 yrs, 69% men).

RESULTS

We compared the HF patients who were treated with loop diuretics (n = 120) with the patients who were not (n = 35). The thigh and arm circumferences were significantly small in the group treated with loop diuretics compared to those not so treated (39.9 ± 4.8 vs. 43.5 ± 6.9 cm, p < 0.001 and 26.7 ± 3.5 vs. 28.9 ± 6.2 cm, p < 0.001, respectively). In a univariate analysis, higher age, lower body mass index, lower hemoglobin, and loop diuretic use were significantly associated with smaller thigh circumference. In a multivariable analysis, the use of loop diuretics was independently associated with smaller thigh circumference (β = -0.51, 95% confidence interval -0.98 to -0.046, p = 0.032).

CONCLUSION

Loop diuretics are associated with decreased thigh and arm circumferences in patients with HF, independent of the severity of HF. Our findings revealed for the first time the adverse effects of loop diuretics on skeletal muscle wasting. These findings will have a significant impact in clinical practice regarding the frequent use of loop diuretics in HF patients.

Nutrition, Physical Exercise, and the Prevalence of Sarcopenia in Elderly Residents in Nursing Homes in China

Background

This study aimed to investigate the factors associated with sarcopenia in elderly residents in three nursing homes in Suzhou City, East China including the association with nutrition and physical exercise.

Material/Methods

Elderly residents (n=316) from three nursing homes included 112 men and 204 women. The appendicular skeletal muscle index (ASMI), grip strength, and movements were measured to diagnose sarcopenia. The correlation between sarcopenia with age, sex, body mass index (BMI), ASMI, upper arm circumference, calf circumference, muscle content, grip strength, dietary intake, degree and duration of movement were also assessed.

Results

The prevalence of sarcopenia was 28.8% (30.4% for men and 27.9% for women). Patients with sarcopenia were older compared with controls. Height, BMI, upper arm circumference, calf circumference and arm muscle mass, lower limb muscle mass, limb skeletal muscle index and ASMI, grip strength, and pace of movement were lower than controls. The prevalence of sarcopenia correlated with the intake of meat, fish, eggs, and milk, and duration of weekly aerobic and resistance exercise. Logistic regression analysis showed a positive correlation between the prevalence of sarcopenia and age, and a negative correlation between BMI and consumption of meat, eggs, and milk.

Conclusions

The prevalence of sarcopenia in elderly residents in three nursing homes in Suzhou City was 28.8%. Increasing age was a risk factor for sarcopenia. Increased BMI and a diet containing meat, eggs, and milk were protective factors. The findings from this study provide support that adequate dietary protein can prevent sarcopenia in the elderly.

Chronic Kidney Disease is Associated with Physical Impairment

Background

Physical impairment or frailty due to sarcopaenia is common in patients with chronic kidney disease and those receiving dialysis. This study examined the association between muscle weakness and kidney function in Japanese patients with chronic kidney disease.

Methods

A total of 23 stable outpatients were enrolled in the study. Several indices were used to assess muscle function; hand grip strength, isometric knee extension strength, Timed Up and Go test (TUG), and the short physical performance battery. The relationships between these indices and estimated glomerular filtration rate (eGFR) as a measure of kidney function were analysed statistically.

Results

Patients' characteristics were as follows: mean age 73.9 years (standard deviation (SD) 13); 12 males, 11 females; body mass index (BMI) 22.5 kg/m² (SD 3.2); serum creatinine (sCr) 4.6 mg/ dl (SD 3.7); estimated glomerular filtration rate (eGFR) 19.1 ml/min (SD 16). Their physical performance indices were: hand grip strength 20.8 kg (SD 7.9); isometric knee extension strength 19.1 kgf/kg (SD 10.6); TUG 14.9 s (SD 6.0); and short physical performance battery score 7.0 (SD 4.3). Multiple regression analysis adjusted for age revealed significant associations between isometric knee extension strength/body weight and eGFR (F [2,19] = 8.38, p = 0.002) and TUG and eGFR (F=4.98 [2,18], p = 0.02).

Conclusion

Deterioration in muscle function or maintenance of posture is associated with chronic kidney disease.

Effect of loop diuretics on skeletal muscle depletion in patients with liver cirrhosis

AIM

Sarcopenia, the loss of skeletal muscle mass, impairs prognosis of patients with liver cirrhosis. The aim of this study was to investigate the effect of loop diuretics, which are frequently used to treat hepatic edema/ascites, on skeletal muscle depletion and the prognosis in patients with liver cirrhosis.

METHODS

This retrospective study evaluated 226 patients with liver cirrhosis. The skeletal muscle cross-sectional area at the level of the third lumbar vertebra was measured using computed tomography. The relative change in skeletal muscle area per year (ΔSMA) was calculated, and the association between ΔSMA and therapeutic dosage of loop diuretics was examined.

RESULTS

The therapeutic dosage of loop diuretics was inversely correlated with ΔSMA by simple (r = -0.27, P < 0.0001) and multiple regression analyses (t = -3.07, P = 0.002). During a median follow-up period of 49 months, 82 patients died. Overall survival rates were lower in patients treated with loop diuretics at >20 mg than in those who received ≤20 mg (median, 66 vs. 97 months; P = 0.002). Multivariate analysis revealed that loop diuretics of >20 mg (hazard ratio [HR], 1.86; 95% confidence interval [CI], 1.03-3.24; P = 0.039) and ΔSMA of ≤-3.1% (HR, 3.87; 95% CI, 2.32-6.60; P < 0.0001) were independently associated with mortality.

CONCLUSIONS

A higher dose of loop diuretic use was associated with more rapid skeletal muscle depletion and poor survival in patients with liver cirrhosis, independent of the severity of liver disease.