Obesity and pulmonary embolism: the mounting evidence of risk and the mortality paradox

Thromb Res. 2011 Dec;128(6):518-23. doi: 10.1016/j.thromres.2011.10.019. Epub 2011 Nov 10.


Purpose: To determine the prevalence of pulmonary embolism in obese patients according to age, gender and comorbid conditions and explore the relation of obesity to mortality.

Methods: The number of patients discharged from short-stay hospitals throughout the United States from 1998-2008 with pulmonary embolism who were obese or not obese, and in-hospital all-cause mortality were determined from the Nationwide Inpatient Sample.

Results: From 1998-2008, 203,500 of 17,979,200 (1.1%) obese patients were diagnosed with pulmonary embolism compared with 2,034,100 of 346,049,800 (0.6%) non-obese patients [relative risk (RR) =2.03]. Relative risk for pulmonary embolism was highest among obese patients aged 11-20 years (RR=5.80) and was higher in obese women (RR=2.08) than in obese men (RR=1.74). Mortality was 4.3% in obese patients with pulmonary embolism compared with 9.5% in non-obese patients (RR=0.45). Obesity had the greatest effect on mortality in older patients and little effect in teenagers and young adults. Among stable patients who did not receive thrombolytic therapy, mortality was 3.8% in obese patients and 8.4% in non-obese patients (RR=0.45). Among unstable patients, obesity had little effect on mortality.

Conclusions: The prevalence of pulmonary embolism in hospitalized patients was higher in obese patients than in non-obese patients. Mortality in patients with pulmonary embolism was lower in obese patients than in non-obese patients, with the greatest effects in women, older patients and stable patients.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Male
  • Middle Aged
  • Obesity / epidemiology
  • Obesity / mortality*
  • Prevalence
  • Pulmonary Embolism / epidemiology
  • Pulmonary Embolism / mortality*
  • Risk Factors
  • United States / epidemiology
  • Young Adult