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

Authors

  • John A. Batsis MD,

    Corresponding author
    1. Section of General Internal Medicine, Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
    • Section of General Internal Medicine, Dartmouth-Hitchcock Medical Center, 1 Medical Center Drive, Lebanon, NH 03755
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    • Telephone: 603-653-9500; Fax: 603-650-0915

  • Jeanne M. Huddleston MD,

    Corresponding author
    1. Hospital Internal Medicine, College of Medicine, Mayo Clinic, Rochester, Minnesota
    2. Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, Minnesota
    • Division of Hospital Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905
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    • Telephone: 507-255-7815;

  • L. Joseph Melton III MD, MPH,

    1. Endocrinology, Diabetes, Metabolism and Nutrition, Department of Medicine, College of Medicine, Mayo Clinic, Rochester, Minnesota
    2. Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, Minnesota
    3. Department of Orthopedic Surgery, College of Medicine, Mayo Clinic, Rochester, Minnesota
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  • Paul M. Huddleston MD, MSc,

    1. Department of Orthopedic Surgery, College of Medicine, Mayo Clinic, Rochester, Minnesota
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  • Dirk R. Larson MS,

    1. Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, Minnesota
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  • Rachel E. Gullerud BS,

    1. Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, Minnesota
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  • M. Molly McMahon MD

    1. Endocrinology, Diabetes, Metabolism and Nutrition, Department of Medicine, College of Medicine, Mayo Clinic, Rochester, Minnesota
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  • Work was performed in part while J.A.B. was at Mayo Clinic Rochester. Dr. Huddleston is supported by grant number 1 KL2 RR024151-01 from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH), and NIH Roadmap for Medical Research. The contents of the manuscript are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH. Information on NCRR is available at http://www.ncrr.nih.gov. The research was made possible by the American Heart Association—National Scientist Development Award (03-30103N-04 to J.M.H.). This study was also made possible by the Rochester Epidemiology Project (Grant # RD1-AR30582, from the National Institute of Arthritis and Musculoskeletal and Skin Diseases). Work was presented in part at the 19th International Association of Gerontology and Geriatrics Congress, Paris, France, July, 2009.

  • Disclosure: Nothing to report.

Abstract

BACKGROUND:

Obese patients are thought to be at higher risk of postoperative medical complications. We determined whether body mass index (BMI) is associated with postoperative in-hospital noncardiac complications following urgent hip fracture repair.

METHODS:

We conducted a population-based study of Olmsted County, Minnesota, residents operated on for hip fracture in 1988 to 2002. BMI was categorized as underweight (<18.5 kg/m2), normal (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30 kg/m2). Postoperative inpatient noncardiac medical complications were assessed. Complication rates were estimated for each BMI category and overall rates were assessed using logistic regression modeling.

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). After adjustment, the risk of developing an inpatient noncardiac complication for each BMI category, compared to normal BMI, was: underweight (odds ratio [OR], 1.33; 95% confidence interval [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 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 (COPD) 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) contributed to an increased risk of developing a postoperative noncardiac 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 postoperative noncardiac medical complications in hip-fracture patients. These results attenuate concerns that obese or frail, underweight hip-fracture patients may be at higher risk postoperatively for inpatient complications. Journal of Hospital Medicine 2009;4:E1–E9. © 2009 Society of Hospital Medicine.

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