Obesity strongly linked to pulmonary embolism and deep venous thrombosis

Since 1927, obesity has been thought to be a risk factor for fatal pulmonary embolism (PE). Because of the high proportion of obesity in the general population, previous studies have not determined whether obesity is an independent risk factor for PE or deep venous thrombosis (DVT). In an extensive study published in the September issue of The American Journal of Medicine, researchers from St. Joseph Mercy Oakland Hospital, Pontiac, Michigan; Wayne State University, Detroit, Michigan; and Oakland University, Rochester, Michigan; analyzed over 20 years of patient records compiled by the National Hospital Discharge Survey (NHDS) to further investigate the potential risk of obesity in venous thromboembolism. The investigators concluded that obesity is a risk factor for venous thromboembolic disease in men as well as women, particularly those under age 40.

The NHDS is comprehensive in its scope including data on patients of all races and ages obtained annually from 181,000 to 307,000 sampled patient abstracts from 400 to 494 non-Federal short-stay hospitals in 50 states and the District of Columbia. There were more than 12,000,000 obese patients and almost 700,000,000 non-obese patients in the sampled data.

The relative risk of DVT, comparing obese patients with non-obese patients, was 2.50. The relative risk of PE was 2.21. Obese females had a greater relative risk for DVT than obese males, 2.75 versus 2.02. Obesity had the greatest impact on patients aged less than 40 years, in whom the relative risk for PE in obese patients was 5.19 and the relative risk for DVT was 5.20. In females aged less than 40 years, the relative risk for DVT comparing obese with non-obese patients was 6.10. In males less than 40 years of age, the relative risk for DVT was 3.71.

Paul D. Stein, MD, writes “Now that we know with certainty that obesity is a risk factor for PE, particularly in men and women under age 40, the presence of obesity may alert physicians to a possibility of the diagnosis. The diagnosis of PE is frequently missed even though PE is the third most common acute cardiovascular disease after myocardial infarction and stroke.”