Background:The number of patients on maintenance hemodialysis (HD) diagnosed with sarcopenia has been increasing through as individuals age. Recent focus is on the condition termed, "dynapenia," which reduces only muscle function, as opposed to sarcopenia, which reduces both muscle mass and function. However, the association between dynapenia and cardio-cerebrovascular (CV) events in patients undergoing HD is largely unknown.
Objectives:The purpose of this study was to evaluate whether sarcopenia and dynapenia are associated with the onset of CV events in patients undergoing HD.
Methods:We retrospectively analyzed 342 patients undergoing HD between January and December 2018. Patients who underwent HD thrice per week for > 3 months were included in the analysis. We adopted the Asian Working Group on Sarcopenia criteria for the diagnosis of sarcopenia and dynapenia.Results: In this study, 244 patients undergoing HD were enrolled. The prevalence of sarcopenia was 38.5%. Sarcopenia was determined to be an independent contributor to CV events in patients undergoing HD. To investigate the clinical relevance of dynapenia in patients with HD, patients without sarcopenia were further divided into dynapenia and non-dynapenia groups. Among 150 patients without sarcopenia, 46 were diagnosed with
ObjectiveClinical feature of heart failure with improved ejection fraction (HFimpEF) remains to be fully elucidated. The present study investigated the association of clinical and echocardiographic parameters with the subsequent improvement of left ventricular ejection fraction (LVEF) in heart failure with reduced ejection fraction (HFrEF).MethodsFrom outpatients with a history of hospitalized for heart failure, 128 subjects diagnosed as HFrEF (LVEF <40%) on heart failure hospitalization were enrolled and longitudinally surveyed. During follow‐up periods more than 1 year, 58 and 42 patients were identified as HFimpEF (improved LVEF to ≥40% and its increase of ≥10 points) and persistent HFrEF, respectively.ResultsThere was no difference in age or sex between the two groups with HFimpEF and persistent HFrEF. The rate of ischemic heart disease was lower and that of tachyarrhythmia was higher in the HFimpEF group than in the persistent HFrEF group. At baseline (i.e., on heart failure hospitalization), LVEF did not differ between the two groups, but left ventricular systolic and diastolic diameters were already smaller and the ratio of early diastolic transmitral velocity to early diastolic tissue velocity (E/e′) was lower in the HFimpEF group. A multiple logistic regression analysis revealed that lower baseline E/e′ was a significant determinant of HFimpEF, independently of confounding factors such as ischemic heart disease, tachyarrhythmia, and baseline left ventricular dimension.ConclusionOur findings indicate that the lower ratio of E/e′ in the acute phase of heart failure onset is an independent predictor of the subsequent improvement of LVEF in HFrEF patients.
Introduction:
In addition to aerobic exercise, it has been recognized that resistance exercise has beneficial effects for the patients with peripheral arterial disease. Recently, muscle-derived exosomes are demonstrated to convey many types of signaling molecules including microRNAs (miRNAs).
Hypothesis:
We assessed the hypothesis that exosomal miRNA secreted by growing muscle promotes angiogenic response in endothelial cells.
Methods:
We utilized skeletal muscle-specific inducible Akt1 transgenic (Akt1-TG) mice that can induce growth of skeletal muscles without exercise training. Exosomes was purified combined usage of ultracentrifugation, and miRNAs were extracted from purified exosomes by spin column-based method. Real-time PCR array and droplet digital PCR was performed to evaluate exosomal miRNA expression.
Results:
Akt1-TG mice showed remarkable skeletal muscle growth 2 weeks after gene activation (weight of gastrocnemius muscle: 0.21±0.03 vs 0.16±0.02, g, p<0.01). The amount of exosomal proteins did not different between Akt1-TG mice and WT mice (977.7±11.3 vs 826.0±45.2, μg/mL serum, p=0.07). KEGG pathway frequency analysis for 4665 target genes identified by real-time PCR array of miRNAs revealed a significant increase in Akt and its downstream signaling pathways. Among upregulated miRNAs, droplet digital PCR identified that miR-1, -133 and -206 expression was significantly upregulated in Akt1 TG mice compared with WT mice in serum. miR206 was increased in IGF-1-stimulated myotubes. PKH26-labeled exosomes were taken up by human umbilical vein endothelial cells. Exogenous supplementation of exosomal miRNA206 promoted angiogenesis as revealed by spheroid assay, and increased expression of HIF-1 and VEGF in endometrial cells.
Conclusions:
Exosomal miR206 was upregulated in blood stream in Akt1-TG mice and IGF-stimulated cultured myotubes. Exogenous supplementation of miR206 promoted angiogenic response in endothelial cells. Our data suggest that miR206 secreted from growing muscle act on endothelial cells and promote angiogenesis.
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