Nutritional risk, inflammation, and hospitalization after hemodialysis initiation

Evidence linking nutritional and inflammatory markers at hemodialysis initiation to subsequent hospital stay remains limited. We examined whether the Geriatric Nutritional Risk Index (GNRI) and C-reactive protein (CRP) at hemodialysis initiation were associated with prolonged post-initiation hospital stay. This single-center retrospective study included patients who initiated hemodialysis during hospitalization and transitioned to maintenance hemodialysis between 2004 and 2024. The primary outcome was hospitalization for 30 days or longer after hemodialysis initiation. Multivariable logistic regression was used with adjustment for age, sex, cardiovascular disease, diabetes mellitus, initiation modality, calendar period, and pre-hemodialysis vascular access status. Among 517 patients, 501 were included in multivariable analysis, and 166 patients (32.1%) experienced prolonged post-initiation stay. A higher GNRI was associated with lower odds of prolonged stay (odds ratio per 1-unit increase, 0.955; 95% confidence interval, 0.925–0.986; p = 0.005), whereas higher log-transformed CRP was associated with higher odds (odds ratio, 1.203; 95% confidence interval, 1.055–1.372; p = 0.006). The low GNRI/high CRP group had the highest odds of prolonged stay (odds ratio, 3.180; 95% confidence interval, 1.489–6.787; p = 0.003), without significant multiplicative interaction. Lower GNRI and higher CRP at hemodialysis initiation were independently and jointly associated with prolonged post-initiation stay. These findings describe associations rather than validated predictions, and prospective evaluation is required before these markers are applied to individual-level risk assessment. Some people who start hemodialysis in hospital need a prolonged stay afterwards. We reviewed records of 517 patients who started hemodialysis during hospitalization at one hospital in Tokyo, Japan, between 2004 and 2024. We examined two measures obtained just before the first hemodialysis session: a nutrition-related score based on blood albumin and body weight (Geriatric Nutritional Risk Index, GNRI) and a blood marker of inflammation (C-reactive protein, CRP). Lower GNRI and higher CRP were associated with staying in hospital for 30 days or longer after starting hemodialysis. Patients with both low GNRI and high CRP were more likely to have a prolonged stay than those with neither. This study of past records shows associations rather than cause and effect. It did not establish whether these measures can predict hospital stay for individual patients. What is known: Malnutrition and inflammation frequently coexist at hemodialysis initiation and predict mortality, but their relationship with the duration of the initiation hospitalization itself has rarely been examined. This study adds: Among 517 patients initiating maintenance hemodialysis during hospitalization over 20 years, lower GNRI and higher CRP immediately before the first session were independently and jointly associated with prolonged post-initiation stay (≥30 days), with broadly consistent directions across alternative outcome definitions and modeling strategies. Potential impact: Two routinely available markers may help characterize illness burden during hemodialysis initiation.