Association Between Malnutrition, Low Muscle Mass, Elevated NT-ProBNP Levels, and Mortality in Hemodialysis Patients

Background/Objectives: Malnutrition, muscle wasting, and fluid overload are highly prevalent in patients undergoing maintenance hemodialysis (HD) and may contribute to increased mortality risk. However, the combined impact of these factors has not been fully elucidated. Methods: In this multicenter prospective cohort study, we enrolled 368 patients in maintenance HD at four dialysis facilities in Japan. Malnutrition was defined as moderate or higher nutritional risk using the nutritional risk index for Japanese hemodialysis patients (NRI-JH). Low muscle mass was assessed using the skeletal muscle mass index (SMI) according to the Asian Working Group for Sarcopenia 2019 (AWGS 2019), and elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) was defined as values in the top quartile (≥7650 pg/mL). Mortality risk was analyzed using Cox proportional hazards models. Associations with inflammation, assessed by C-reactive protein (CRP), were also explored. Results: Over a three-year follow-up period, 52 deaths occurred. Malnutrition, low muscle mass, and elevated NT-proBNP were each independently associated with increased all-cause mortality (HR: 4.98, 3.25, and 5.45, respectively). Patients with multiple concurrent risk factors had significantly worse survival. Although CRP was positively associated with these risk factors, it was not an independent predictor of mortality. Conclusions: Malnutrition, low muscle mass, and elevated NT-proBNP are independent and additive risk factors for mortality in HD patients. These findings highlight the need for integrated assessment and management strategies to improve prognoses in this high-risk population.