Association between reduced muscle mass and inflammatory intensity in hemodialysis patients

Abstract

Background: Chronic kidney disease (CKD) is a major global public health problem, affecting more than 10% of the world’s population, over 850 million people worldwide. Protein-energy wasting (PEW), which is observed in 28–54% of patients undergoing hemodialysis, is closely associated with reduced muscle mass and has been shown to double the risk of mortality within 5 years. Chronic inflammation and hemodynamic instability during hemodialysis are considered key mechanisms contributing to muscle mass loss in CKD. Aim: To determine muscle mass and the intensity of inflammatory response in hemodialysis patients, and evaluate their association Materials and Methods: Skeletal muscle mass (SMM) was assessed after hemodialysis using bioelectrical impedance analysis (InBody 770, USA). The skeletal muscle mass index (SMMI) was calculated as muscle mass (kg) divided by height squared (m²). Blood samples were obtained from the participants prior to hemodialysis, and the intensity of the inflammatory response was assessed using the level of C-reactive protein (CRP) and the CRP-to-albumin ratio (CRP/Alb). In addition, based on complete blood count parameters, the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), as well as the systemic immune–inflammation index (SII), systemic inflammation response index (SIRI), and aggregate index of systemic inflammation (AISI) were calculated and evaluated. Results: A total of 128 hemodialysis patients were enrolled, including 50.8% males and 49.2% females, with a mean age of 55.37±14.87 years. No statistically significant differences in SMM (F=2.22, p=0.113) or SMMI (F=7.47, p=0.48) were observed across age groups. However, when stratified by duration of hemodialysis (≤3 years vs >3 years), independent samples t-test demonstrated significant differences in both SMM (26.2±5.2 vs 22.8±4.4; t=2.645, p=0.009) and SMMI (24.9±10.2 vs 22.9±9.7; t=3.020, p=0.003). Pearson correlation analysis showed that SMMI was significantly inversely correlated with CRP (r=−0.368, p<0.0001), MLR (r=−0.321, p<0.0001), SIRI (r=−0.210, p=0.02), AISI (r=−0.252, p=0.004), and CRP/Alb (r=−0.260, p=0.003). Conclusion: In hemodialysis patients, increased inflammatory response intensity was associated with reduced skeletal muscle mass and may represent one of the underlying pathophysiological mechanisms (SMMI vs. CRP, r=−0.368, p<0.0001; SMMI vs. MLR, r=−0.321, p<0.0001; SMMI vs. SIRI, r =−0.210, p=0.02; SMMI vs. AISI, r=−0.252, p=0.004; SMMI vs. CRP/Alb, r=−0.260, p=0.003).