Short-term prognosis of emergently hospitalized dialysis-independent chronic kidney disease patients: A nationwide retrospective cohort study in Japan

PLoS One. 2018 Nov 29;13(11):e0208258. doi: 10.1371/journal.pone.0208258. eCollection 2018.


In patients with chronic kidney disease (CKD), low body mass index (BMI) is associated with high mortality. This relationship in emergently hospitalized CKD patients is unknown. We investigated the association between obesity and short-term mortality in emergently admitted patients with dialysis-independent CKD (DI-CKD) with and without infection. This retrospective cohort study examined Diagnosis Procedure Combination data of 26103 emergently hospitalized DI-CKD patients. Patients were divided into 8 groups according to their BMI and the presence of infectious diseases. The primary outcome was in-hospital death within 100 days. Cox proportional hazards models adjusted for baseline characteristics showed that low BMI was associated with the outcome both in infected and in non-infected patients (reference group as non-infected and medium BMI [24-26 kg/m2] group): infected and the lowest BMI (≤20 kg/m2) group, hazard ratio (HR) 1.82 (95% confidence interval 1.51, 2.19); non-infected and the lowest BMI group, 1.39 (1.16, 1.67). When patients were stratified according to presence of diabetes mellitus (DM), patients with DM showed that low BMI was associated with the outcome both in infected and in non-infected patients, whereas in non-DM patients, this relationship was attenuated in the non-infected group. For emergently hospitalized CKD patients with infection, high BMI was associated with lower mortality irrespective of the DM status. For non-infected patients, the effects of obesity for in-hospital mortality were modified by the DM status.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Body Mass Index
  • Communicable Diseases / complications
  • Diabetes Complications / complications
  • Emergency Medical Services
  • Female
  • Hospitalization
  • Humans
  • Japan / epidemiology
  • Male
  • Middle Aged
  • Obesity / complications
  • Prognosis
  • Proportional Hazards Models
  • Renal Dialysis
  • Renal Insufficiency, Chronic / complications*
  • Renal Insufficiency, Chronic / diagnosis*
  • Renal Insufficiency, Chronic / epidemiology
  • Retrospective Studies
  • Risk Factors
  • Young Adult

Grants and funding

This study was supported by Grants for Research on Policy Planning and Evaluation from the Ministry of Health, Labour, and Welfare, Japan (grant numbers: H27-Policy-Designated-009) (, and Grants-in-Aid for Scientific Research (C) (16K09642) to TR from the Japan Society for the Promotion of Science ( There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.