BackgroundSarcopenia, the progressive loss of muscle mass and strength, is common among patients with chronic kidney disease, especially those on maintenance hemodialysis. This condition often arises from factors like reduced physical activity and metabolic changes associated with chronic kidney disease. This study aims to assess the prevalence and severity of sarcopenia in patients on maintenance hemodialysis (MHD), focusing on probable sarcopenia and its correlations with physical activity, body mass index, and inorganic phosphorus levels.MethodsThis cross-sectional study involved 220 patients on MHD who visited to West China Hospital of Sichuan University between February and April 2023. The demographic data, body measurements, and laboratory results were retrospectively collected. Sarcopenia was assessed using the 2019 criteria from the Asian Working Group and the European Working Group on Sarcopenia in Older People, and physical activity was measured via the International Physical Activity Questionnaire.ResultsOf the study participants, 141 (64.1%) were diagnosed with probable [110 (50.0%) or confirmed sarcopenia [31 (14.1%)], including 22 (10%) with severe sarcopenia. Multivariable logistic regression analysis revealed that physical activity (International Physical Activity Questionnaire score, OR = 0.998, 95% CI: 0.998–0.999, P < 0.001), body mass index (OR = 0.868, 95% CI: 0.788–0.957, P = 0.004), and inorganic phosphorus levels (OR = 0.513, 95% CI: 0.270–0.975, P = 0.042) independently influenced the likelihood of sarcopenia. Within the sarcopenic group, physical activity and BMI significantly correlated with the condition’s severity.ConclusionThe prevalence of probable or confirmed sarcopenia in patients on MHD is significant. Factors such as physical activity, body mass index, and inorganic phosphorus levels are independently associated the presence and severity of sarcopenia in this population.Trial registrationChinese Clinical Trial Registry (ChiCTR2100051111), registered on 2021–09–13.