Unveiling genetic variants for age-related sarcopenia by conducting a genome-wide association study on Korean cohorts.

Sarcopenia is an age-related disorder characterised by a progressive decrease in skeletal muscle mass. As the genetic biomarkers for sarcopenia are not yet well characterised, this study aimed to investigate the genetic variations related to sarcopenia in a relatively aged cohort, using genome-wide association study (GWAS) meta-analyses of lean body mass (LBM) in 6961 subjects. Two Korean cohorts were analysed, and subgroup GWAS was conducted for appendicular skeletal muscle mass (ASM) and skeletal muscle index. The effects of significant single nucleotide polymorphisms (SNPs) on gene expression were also investigated using multiple expression quantitative trait loci datasets, differentially expressed gene analysis, and gene ontology analyses. Novel genetic biomarkers were identified for LBM (rs1187118; rs3768582) and ASM (rs6772958). Their related genes, including RPS10, NUDT3, NCF2, SMG7, and ARPC5, were differently expressed in skeletal muscle tissue, while GPD1L was not. Furthermore, the 'mRNA destabilisation' biological process was enriched for sarcopenia. Our study identified RPS10, NUDT3, and GPD1L as significant genetic biomarkers for sarcopenia. These genetic loci were related to lipid and energy metabolism, suggesting that genes involved in metabolic dysregulation may lead to the pathogenesis of age-related sarcopenia.

Clinical and psychosocial factors predicting health-related quality of life in hemodialysis patients.

Many patients with end-stage renal disease have significant impairment in health-related quality of life (HRQoL). Most previous studies have focused on clinical factors; however, quality of life can also be affected by psychosocial factors. The aim of this study was to identify the possible predictors of HRQoL among clinical and psychosocial factors in hemodialysis (HD) patients. The study included 101 patients who were undergoing HD. Psychosocial factors were evaluated using the Hospital Anxiety and Depression Scale, Multidimensional Scale of Perceived Social Support, Montreal Cognitive Assessment, and Pittsburgh Sleep Quality Index. We also assessed laboratory and clinical factors, including albumin, Kt/V as a marker of dialysis adequacy, normalized protein catabolic rate, and duration of HD. The Euro Quality of Life Questionnaire 5-Dimensional Classification (EQ-5D) was used to evaluate HRQoL. The mean EQ-5D index score was 0.704 ± 0.199. The following variables showed a significant association with the EQ-5D index: age (P < 0.001), depression (P < 0.001), anxiety (P < 0.001), support from friends (P < 0.001), cognitive function (P < 0.001), duration of HD (P = 0.034), triglyceride (P = 0.031), total iron-binding capacity (P = 0.036), and phosphorus (P = 0.037). Multiple regression analysis showed that age (95% confidence interval [CI] -0.008 to -0.002), anxiety (95% CI -0.025 to -0.009), and support from friends (95% CI 0.004 to 0.018) were independent predictors of impaired HRQoL. This study explored determinants of impaired HRQoL in HD patients. We found that impaired HRQoL was independently associated with age, anxiety, and support from friends. We should consider psychosocial as well as clinical factors when evaluating ways to improve HRQoL in HD patients.