higher likelihood of urgent dialysis initiation and early mortality. Body mass index (BMI) has been proposed as a risk factor for PO-AKI, but findings are inconsistent, and data on urgent-start dialysis are limited. We aimed to evaluate the association between BMI and postoperative urgent-start hemodialysis after lower gastrointestinal (GI) surgery. Methods: This retrospective observational cohort study used data from the nationwide administrative claims and the DPC database. In brief, >1, 000 hospitals, including all 81 academic hospitals in Japan, contribute to the DPC database. Approximately 7, 000, 000 cases are added to the database annually and include almost 50% of all hospital admissions in Japan. Patients aged 18-89 years who underwent lower GI surgery were included. Non-dialysis-dependent Chronic Kidney Disease (NDD-CKD) was defined as registry-listed CKD (stages 2-5) with no dialysis before hospital day 4. Participants were stratified into quartiles based on their BMI: Q1 (low BMI: # 19. 7 kg/m2), Q2 (normal BMI: 19. 7-22. 1 kg/m2), Q3 (high BM: 22. 1-24. 7 kg/m2), and Q4 (obese BMI: 24. 7 kg/m2). The primary outcome was postoperative urgent-start hemodialysis during the index hospitalization. Multivariate logistic regression analysis was used to estimate adjusted odds ratios (aORs) across BMI quartiles, adjusting for baseline characteristics. Results: Of 156, 851 patients, 2, 814 had NDD-CKD and 154, 037 had no CKD. The mean age of the cohort was 65. 7 17. 2 years, with 53. 8% (n = 110, 275) being men. Among NDD-CKD patients, the proportion of postoperative urgent-start dialysis was highest in the low BMI group (Q1: 28. 1%) compared with the normal BMI (Q2: 26. 4%), high BMI (Q3: 17. 5%), and obese BMI (Q4: 18. 1%) groups. After adjustment, higher BMI was associated with lower odds of urgent-start dialysis (Q4 vs Q2: aOR 0. 93, 95% CI 0. 883-0. 973, p<0. 001;Q3 vs Q2: aOR 0. 95, 95% CI 0. 903-0. 994). Conversely, among non-CKD patients, the proportion requiring urgent-start dialysis was highest in the obese BMI group (Q4: 0. 51%) versus the normal BMI group (Q2: 0. 20%). Adjusted analysis showed higher odds in Q4 (Q4 vs Q2: aOR 1. 004, 95% CI 1. 002-1. 005, p<0. 001). Conclusion: Among patients with NDD-CKD undergoing lower GI surgery, higher BMI (Q3-Q4) was associated with lower odds of postoperative urgent-start dialysis. However, among non-CKD patients, higher BMI was associated with higher odds of urgent-start dialysis. The impact of elevated BMI on postoperative renal outcomes appears to differ by baseline CKD status. I have no potential conflict of interest to disclose. I did not use generative AI and AI-assisted technologies in the writing process.
Foula et al. (Wed,) studied this question.