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DOS Kongressen 2016 ·
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Impact of body mass index on risk of acute renal
failure and mortality in elderly patients undergoing
hip fracture surgery
Alma B Pedersen, Henrik Gammelager, Johnny Kahlert, Henrik Toft Sørensen,
Christian F Christiansen
Department of Clinical Epidemiology, Aarhus University Hospital
Background:
Fractures of the hip represent a major worldwide public health
problem, associated with significant mortality.
Purpose / Aim of Study:
To examine risk of postoperative acute renal failure
(ARF) and subsequent mortality, by body mass index (BMI) level, in hip fracture
surgery patients aged 65 and over.
Materials and Methods:
Regional cohort study using medical databases. We
included all patients who underwent surgery to repair a hip fracture during
2005-2011 (n=13,529) at hospitals in Northern Denmark. We calculated cu-
mulative risk of ARF by BMI level during 5 days post-surgery, and subsequent
short-term (6-30 days post-surgery) and long-term (31-365 days post- sur-
gery) mortality. We calculated crude and adjusted hazard ratios (aHRs) for ARF
and death with 95% confidence intervals (CIs), comparing underweight, over-
weight, and obese patients with normal-weight patients.
Findings / Results:
Risks of ARF within 5 postoperative days were 11.9%,
10.1%, 12.5%, and 17.9% for normal-weight, underweight, overweight, and
obese patients, respectively. Among those who developed ARF, short-term
mortality was 14.1% for normal-weight patients, compared to 23.1% for un-
derweight (aHR 1.7 (95% CI: 1.2-2.4)), 10.7% for overweight (aHR 0.9 (95%
CI: 0.6-1.1)), and 15.2% for obese (aHR 0.9 (95% CI: 0.6-1.4)) patients. Long-
term mortality was 24.5% for normal-weight, 43.8% for underweight (aHR 1.6
(95% CI: 1.0- 2.6)), 20.5% for overweight (aHR 0.8 (95% CI: 0.6-1.2)), and
21.4% for obese (aHR 1.1 (95% CI: 0.7-1.8) ARF patients.
Conclusions:
Obese patients were at increased risk of ARF compared with
normal-weight patients. Among patients who developed ARF, overweight and
obesity were not associated with mortality. Compared to normal-weight pa-
tients, underweight patients had elevated mortality for up to one year after hip
fracture surgery followed by ARF.
No conflicts of interest reported
174.