rss
Thorax 2010;65:44-50 doi:10.1136/thx.2009.117572
  • Acute lung injury

Body mass index is associated with the development of acute respiratory distress syndrome

  1. M N Gong1,
  2. E K Bajwa2,
  3. B T Thompson2,
  4. D C Christiani3
  1. 1
    Division of Critical Care Medicine, Department of Medicine, Montefiore Medical Center, Bronx, New York, USA
  2. 2
    Pulmonary and Critical Care Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
  3. 3
    Environmental Health Department (Environmental and Occupational Medicine and Epidemiology Program), Harvard School of Public Health, Boston, Massachusetts, USA
  1. Correspondence to Dr D C Christiani, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA; dchris{at}hsph.harvard.edu
  • Received 6 April 2009
  • Accepted 14 August 2009
  • Published Online First 21 September 2009

Abstract

Background: The relationship between body mass index (BMI) and development of acute respiratory distress syndrome (ARDS) is unknown.

Methods: A cohort study of critically ill patients at risk for ARDS was carried out. BMI was calculated from admission height and weight. Patients were screened daily for AECC (American European Consensus Committee)-defined ARDS and 60-day ARDS mortality.

Results: Of 1795 patients, 83 (5%) patients were underweight (BMI <18.5 kg/m2), 627 (35%) normal (BMI 18.5–24.9), 605 (34%) overweight (BMI 25–29.9), 364 (20%) obese (BMI 30–39.9) and 116 (6%) severely obese (BMI ≥40). Increasing weight was associated with younger age (p<0.001), diabetes (p<0.0001), higher blood glucose (p<0.0001), lower prevalence of direct pulmonary injury (p<0.0001) and later development of ARDS (p = 0.01). BMI was associated with ARDS on multivariate analysis (ORadj 1.24 per SD increase; 95% CI 1.11 to 1.39). Similarly, obesity was associated with ARDS compared with normal weight (ORadj 1.66; 95% CI 1.21 to 2.28 for obese; ORadj 1.78; 95% CI 1.12 to 2.92 for severely obese). Exploratory analysis in a subgroup of intubated patients without ARDS on admission (n = 1045) found that obese patients received higher peak (p<0.0001) and positive end-expiratory pressures (p<0.0001) than non-obese patients. Among patients with ARDS, increasing BMI was associated with increased length of stay (p = 0.007) but not with mortality (ORadj 0.89 per SD increase; 95% CI 0.71 to 1.12).

Conclusion: BMI was associated with increased risk of ARDS in a weight-dependent manner and with increased length of stay, but not with mortality. Additional studies are needed to determine whether differences in initial ventilator settings may contribute to ARDS development in the obese.

Footnotes

  • ‣ Additional tables are published online only at http://thorax.bmj.com/content/vol65/issue1

  • Funding The present work is supported by research grants HL60197, HL084060 and HL086667 from NHLBI.

  • Competing interests None.

  • Ethics approval The Human Subjects Committees of the MGH, BIDMC and Harvard School of Public Health approved this study.

  • Provenance and Peer review Not commissioned; externally peer reviewed.

This Article

  1. Abstract
  2. Full text
  3. PDF
  4. All Versions of this Article:
    1. thx.2009.117572v1
    2. 65/1/44 most recent

Social bookmarking

Register for free content


Free sample
 This recent issue is free to all users to allow everyone the opportunity to see the full scope and typical content of Thorax.
View free sample issue >>

Free archive
The full back archive is now available for Thorax. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006, back to volume 1 issue 1.
Register to access the free archive >>

Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.