Sarcopenia is a prevalent complication among patients undergoing maintenance hemodialysis. This condition is characterized by the loss of muscle proteins, diminished muscle strength, and impaired functional capacity [1]. The prevalence of sarcopenia within the overall dialysis population is documented at a minimum of 28.5 % (95 % CI: 22.9–34.1 %) [2], with a corresponding rate of 26.8 % (95 % CI: 22.8 %–31.2 %) in the maintenance hemodialysis (MHD) subgroup [3]. Sarcopenia is closely associated with an elevated risk of cardiovascular events, infection-related fatalities, and all-cause mortality in patients undergoing MHD [4]. In accordance with the diagnostic criteria established by the Asian Working Group for Sarcopenia in 2019, the diagnosis of sarcopenia is warranted if grip strength falls below 28 kg in males and 18 kg in females or if the appendicular skeletal muscle mass index (assessed through bioelectrical impedance) registers less than 7.0 kg/m² in males and 5.7 kg/m² in females. Additionally, a 6-min walk distance of less than 1.0 m/s in either sex serves as an indicator for diagnosis [5].

Manganese (Mn), an indispensable trace element in the human body,with the normal ranges of 4–15 μg/L in blood, 1–8 μg/L in urine and 0.4–0.85 μg/L in serum, plays a pivotal role in a multitude of physiological processes, including reproduction, growth, immune function, energy homeostasis, and antioxidant defense. Its significance extends to the regulation of lipid, carbohydrate, and protein metabolism through coenzyme participation of specific enzymes [6]. Previous investigations have established pronounced associations between iron [7], zinc [8], selenium [9], lead, mercury, and cadmium [10] and the incidence of sarcopenia in diverse populations. However, the association between Mn and sarcopenia remains unclear, particularly among patients undergoing maintenance hemodialysis. And most current studies of trace element imbalances in HD patients have analyzed their serum/plasma concentrations [11], [12], with only a few focusing on blood analysis [13], [14]. But in most cases, circulating trace elements are not uniformly distributed between plasma and cellular blood components.According to research, only about 4 % of circulating Mn is present in plasma, with 66 % found in erythrocytes and the remaining 30 % in leukocytes and platelets [15]. It complexes with other substances, resulting in low plasma and tissue concentrations [16], so it may be more accurate to assess the overall distribution of manganese in blood than in serum or plasma. The primary objective of this study was to elucidate this relationship between blood manganese and sarcopenia using a comprehensive cross-sectional analysis.