PW24 - ASSOCIATION OF BMI WITH IN-HOSPITAL MORTALITY AND CLINICAL OUTCOMES IN PATIENTS WITH HIP FRACTURE: A NATIONWIDE INPATIENT DATABASE STUDY
PW24
ASSOCIATION OF BMI WITH IN-HOSPITAL MORTALITY AND CLINICAL OUTCOMES IN PATIENTS WITH HIP FRACTURE: A NATIONWIDE INPATIENT DATABASE STUDY
A. Saito1,*, Y. Ishida2, T. Inoue3, F. Kawase4, A. Nagano5, J. Ueshima6, K. Murotani7,8, K. Maeda9,10
1Department of Nutrition, Yoshida Hospital, Niigata, 2Department of, Aichi Medical University Hospital, Aichi, 3Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, 4Department of Nutrition, Asuke Hospital Aichi Prefectural Welfare Federation of Agricultural Cooperatives, Aichi, 5Clinical Nurse Consultant Ca-resso, Hyogo, 6Department of Nutritional Service, NTT Medical Center Tokyo, Tokyo, 7School of Medical Technology, 8Biostatistics Center, Kurume University, Fukuoka, 9Nutrition Therapy Support Center, Aichi Medical University Hospital, 10Department of Geriatric Medicine, National Center for Geriatrics and Gerontology, Aichi, Japan
Rationale: Older Asian adults with hip fracture often face serious outcomes, including in-hospital death. This study aimed to examine the potentially non-linear association between BMI at admission and in-hospital mortality using a nationwide inpatient database, to inform prognosis and nutritional care.
Methods: This retrospective observational study used data from a nationwide inpatient database in Japan (2014–2022). Patients aged ≥65 years who underwent hip fracture surgery were included. BMI at admission was categorized using WHO Asian criteria: underweight (<18.5), normal (18.5–22.9), overweight (23–27.4), and obese (≥27.5). The primary outcome was in-hospital mortality; secondary outcomes included in-hospital complications and Barthel Index (BI) at discharge. Multivariable Cox, logistic, and linear regression models were applied.
Results: A total of 146,699 patients were included (mean age 84.5 ± 7.5 years; 78.4% female). Based on BMI classification, 35,944 (24.5%) were underweight, 75,141 (51.2%) normal weight, 31,382 (21.4%) overweight, and 4,232 (2.9%) obese. Underweight was associated with a significantly higher risk of in-hospital mortality compared to normal weight (HR 1.52 [95% CI 1.40–1.66]). In contrast, overweight and obesity were associated with significantly lower mortality risks (HR 0.67 [0.59–0.75] and HR 0.71 [0.53–0.95], respectively). HR for in-hospital mortality, estimated using restricted cubic spline regression, showed a gentle U-shaped association with BMI. The incidence of complications was higher in the underweight group (OR 1.10 [1.07–1.13]), while both overweight and obese groups had lower risks (OR 0.92 [0.89–0.94] and OR 0.89 [0.84–0.95], respectively). Regarding functional outcomes, BI scores at discharge were significantly lower in the underweight group and significantly higher in the overweight and obese groups (β = –3.85, 3.34, and 3.72, respectively; P < 0.001 for all).
Conclusion: Higher BMI at admission was associated with lower in-hospital mortality and complications, and better functional outcomes at discharge. These findings suggest that nutritional management to manage BMI prior to injury might benefit older hip fracture patients.
Disclosure of Interest: None declared