Body mass index (BMI) and risk of noncardiac postoperative medical complications in elderly hip fracture patients: A population‐based study

Abstract

Background Obese patients are thought to be at higher risk of post-operative medical complications. We sought to determine whether body mass index (BMI) is associated with post-operative in-hospital non-cardiac complications following urgent hip fracture repair. Methods We conducted a population-based study of Olmsted County, Minnesota residents operated for hip fracture in 1988–2002. BMI was categorized as underweight (<18.5kg/m2), normal (18.5–24.9kg/m2), overweight (25.0–29.9kg/m2) and obese (≥30kg/m2). Post-operative inpatient non-cardiac medical complications were assessed. Complication rates were estimated for each BMI category and overall complication rates were assessed using logistic regression models adjusted for age, sex, calendar year, and American Society of Anesthesia (ASA) class. Results There were 184 (15.6%) underweight, 640 (54.2%) normal, 251 (21.3%) overweight, and 105 (8.9%) obese hip fracture repairs (mean age, 84.2±7.5 years; 80% female). No significant difference was found among the BMI categories for baseline ASA status (ASA III–IV vs. I–II; p=0.14). After adjustment, the risk of developing an inpatient non-cardiac complication for each BMI category, compared to normal BMI, was: underweight (OR 1.33; 95%CI: 0.95–1.88; p=0.10), overweight (OR 1.01;95%CI: 0.74–1.38; p=0.95), and obese (OR 1.28;95%CI: 0.82–1.98; p=0.27). Multivariate analysis using stepwise selection demonstrated that an ASA status of III–V vs. I–II(OR 1.84, 95%CI: 1.25–2.71; p=0.002), a history of chronic obstructive pulmonary disease or asthma (OR 1.58; 95%CI: 1.18–2.12; p=0.002), male sex (OR 1.49, 95%CI:1.10–2.02; p=0.01) and older age (OR 1.05;95%CI: 1.03–1.06; p<0.001), significantly contributed to an increased risk of developing a post-operative non-cardiac inpatient complication. Underweight patients had higher in-hospital mortality rates than normal BMI patients (9.3 vs. 4.4%; p=0.01). Conclusions BMI has no significant influence on post-operative non-cardiac medical complications in hip fracture patients. These results attenuate concerns that obese or frail underweight hip fracture patients may be at higher risk post-operatively for inpatient complications.

Obesity and fractures

“…2014;58/5 elderly subjects or individuals with chronic diseases) but are associated with better survival. Obesity seemed not to be deleterious in a population cohort of Olmsted Country (Minessota, US), where the risk of cardiac and non-cardiac post-operative complications was similar among overweight, obese patients and subjects within the normal weight range (62,63).…”

Obesity and fracture in men and women: An epidemiologic perspective

“…The risk of all noncardiac medical complications following hip fracture did not differ by BMI level. (82) There appears to be little information concerning other potential adverse consequences of fracture in the obese elderly (eg, functional limitation or loss of independence), and the issue deserves further examination, particularly in light of the prevalence of fracture in those with obesity. Losses in BMD and lean body mass and gains in fat have been observed for hip fracture cases.…”

Clinical presentation and outcome of perioperative myocardial infarction in the very elderly following hip fracture surgery

“…1-3 Perioperative ischemic symptoms are often masked by analgesia, sedation, and transient and subtle ECG changes. Postoperative troponin measurement is not routinely done for PMI diagnosis.…”