Time-varying effects of body mass index on mortality among hemodialysis patients: Results from a nationwide Korean registry
Autor: | Sejoong Kim; Jong Cheol Jeong; Shin Young Ahn; Kibbeum Doh; Dong-Chan Jin; Ki Young Na |
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Sprache: | Englisch; Koreanisch |
Veröffentlicht: |
2019 |
Quelle: | Directory of Open Access Journals: DOAJ Articles |
Online Zugang: |
https://doi.org/10.23876/j.krcp.18.0094 https://doaj.org/toc/2211-9132 2211-9132 doi:10.23876/j.krcp.18.0094 https://doaj.org/article/e379dfc0232f423abd908b3ec4265070 https://doi.org/10.23876/j.krcp.18.0094 https://doaj.org/article/e379dfc0232f423abd908b3ec4265070 |
Erfassungsnummer: | ftdoajarticles:oai:doaj.org/article:e379dfc0232f423abd908b3ec4265070 |
Zusammenfassung
Background : Unlike patterns observed in the general population, obesity is associated with better survival among hemodialysis patients, which could be explained by reverse causation or illness-related weight loss. However, the time-varying effect of body mass index (BMI) on hemodialysis survival has not been investigated. Therefore, this study investigated the time-varying effect of BMI on mortality after starting hemodialysis. Methods : In the present study, we examined Korean Society of Nephrology data from 16,069 adult patients who started hemodialysis during or after the year 2000. Complete survival data were obtained from Statistics Korea. Survival analysis was performed using Cox regression and a non-proportional hazard fractional polynomial model. Results : During the median follow-up of 8.6 years, 9,272 patients (57.7%) died. Compared to individuals with normal BMI (18.5-24.9 kg/m2), the underweight group (< 18.5 kg/m2) had a higer mortality hazard ratio (HR, 1.292; 95% confidence interval [CI], 1.203-1.387; P < 0.001) and the overweight group (25.0-29.9 kg/m2) had a lower mortality HR (0.904; 95% CI, 0.829-0.985; P = 0.022). The underweight group had increasing HRs during the first 3 to 7 years after starting hemodialysis, which varied according to age group. The young obese group (< 40 years old) had a U-shaped temporal trend in their mortality HRs, which reflected increased mortality after 7 years. Conclusion : The obese hemodialysis group had better survival during the early post-dialysis period, although the beneficial effect of obesity disappeared 7 years after starting hemodialysis. The young obese group also had an increased mortality HR after 7 years.