Coronavirus disease 2019 (COVID-19) vaccination reduces the risk of progression to severe COVID-19 in the general population. To examine that preventive effect in dialysis patients, the association of vaccination status with severe COVID-19 progression was investigated in this retrospective observational study conducted from December 2020 to May 2022 of 100 such patients hospitalized for non-severe COVID-19 at Inoue Hospital (Suita, Japan). Fifty-seven were fully vaccinated, defined as receiving a COVID-19 vaccine second dose at least 14 days prior to the onset of COVID-19, while 43 were not. Among all patients, 13 (13.0%) progressed to severe COVID-19 with a median (interquartile range) time of 6 (2.5–9.5) days, while 87 (87.0%) were discharged after 11 (8–16) days. Kaplan–Meier analysis showed that fully vaccinated patients had a significantly lower rate of progression to severe COVID-19 (p = 0.001, log-rank test). Cox proportional hazard analysis also indicated that full COVID-19 vaccination was significantly associated with reduced instances of progression to severe COVID-19 (hazard ratio 0.104, 95% confidence interval 0.022 to 0.483; p = 0.004) after balancing patient background characteristics using an inverse probability of treatment weight method. These results suggest that full vaccination status contributes to reducing the risk of progression from non-severe to severe COVID-19 in dialysis patients.

Hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitors continually stabilize hypoxia-inducible factor-1α (HIF-1α). These inhibitors are effective in the clinical treatment of renal anemia. However, the effects of continued HIF-1α stabilization on skeletal muscle differentiation remain unclear. This study aimed to investigate the effects of continued HIF-1α stabilization on skeletal muscle differentiation using a HIF-PH inhibitor in both in vitro and in vivo models. We cultured mouse C2C12 myoblasts to differentiate into myotubes with or without FG-4592, a HIF-PH inhibitor. Additionally, we treated nine-week-old male C57BL/6 mice with either FG-4592 or vehicle via intraperitoneal injections three times a week for four weeks. In vitro, FG-4592 treatment stabilized HIF-1α continually. Morphological analysis revealed that 72 h FG-4592 treatment suppressed differentiation of C2C12 myoblasts into myotubes. This treatment decreased the gene and protein expression of MyoD and myogenin, reduced the protein expression of myosin heavy chain (MHC), and increased the gene and protein expression of myostatin. HIF-1α knockdown mitigated the decrease in MHC protein expression induced by FG-4592. In vivo, FG-4592 treatment increased HIF-1α protein expression and decreased MyoD, myogenin, and MHC protein expression in gastrocnemius muscle. These findings suggest that pharmacological HIF-PH inhibition suppresses myoblast differentiation through continued HIF-1α stabilization.