Nutritional risk is associated with frailty in Japanese patients undergoing hemodialysis: a multicenter cross-sectional study

Background Frailty is increasingly recognized as a clinically important condition among patients receiving maintenance hemodialysis, who often experience a high burden of comorbidity together with nutritional and functional decline. A simple nutritional risk index used in hemodialysis care (NRI-JH) is commonly applied to identify patients at high risk of mortality; however, its association with frailty remains unclear. Methods This multicenter cross-sectional study included 226 maintenance hemodialysis patients from four affiliated facilities in Japan. The Nutritional Risk Index for Japanese Hemodialysis Patients (NRI-JH)—a 14-point score based on body mass index, albumin, total cholesterol, and creatinine—was calculated per the original definition. Frailty was assessed using the revised Japanese Cardiovascular Health Study (J-CHS) criteria. We examined correlation (Spearman’s ρ), identified factors associated with pre-frailty/frailty using multivariable logistic regression (odds ratio per 1-point increase in NRI-JH), and evaluated discrimination by the area under the receiver operating characteristic curve (AUC). Results Age was 62 ± 15 years; 172 were men (76.1%). Mean grip strength was 25.5 ± 8.8 kg overall, 27.7 ± 8.4 kg in men, and 18.3 ± 5.5 kg in women. Muscle weakness (grip strength) was present in 192 participants (85.0%), and slowness (gait speed) in 53 (23.5%). Overall, 117 participants (51.8%) were classified as pre-frail and 126 (55.8%) as frail according to the J-CHS criteria. NRI-JH correlated with J-CHS score (Spearman’s ρ = 0.29; p < 0.0001). Higher NRI-JH was associated with pre-frailty (odds ratio [OR] 1.12; 95% confidence interval [CI] 1.02–1.25) and frailty (OR 1.10; 95% CI 1.00–1.22). Muscle weakness and slowness were significantly associated with NRI-JH. AUC for pre-frailty and frailty were 0.634–0.637 for NRI-JH alone and improved to 0.740–0.804 when combined with grip strength and gait speed. Conclusions NRI-JH was significantly associated with frailty and showed moderate discriminatory ability. Adding two brief performance measures—grip strength and gait speed—enhanced pragmatic risk stratification, supporting a stepwise screening approach in hemodialysis care.