Severe obesity may contribute to infection risk after bypass surgery

Severely obese patients who undergo a coronary artery bypass are more likely to develop an infection after surgery and stay in hospital longer, compared with people of normal weight, according to a study published in the Journal of the American Heart Association.

Overweight stomach (shallow focus)

It appears that addressing infection risk might be an effective strategy to decrease the length-of-stay for patients with obesity who undergo coronary artery bypass surgery."

Mary Forhan, Senior author of the paper, University of Alberta, Canada.

The findings come from an analysis of data on 7,560 patients who had undergone bypass surgery in Edmonton between April 2003 and March 2014.

Forhan and colleagues divided the patients into five groups based on their body mass index, with 20% of patients being classed as normal weight (BMI 18.5–24.9); 40.7% as overweight (25–29.9); 25.7% as obesity class I (30–34.9), 9.2% as obesity class II (35–39.9), and 4.4% as obesity class III (40 or higher).

The researchers found that, compared with normal weight individuals, severely obese (class III) individuals were 56% more likely to develop overall complications within a month of having their surgery and that moderately obese (class II) patients were 35% more likely.

Severely obese patients were also three times more likely to develop an infection and stayed in hospital for an average of one day longer than normal-weight people. Among those with severe obesity, patients who had diabetes and developed an infection stayed in hospital 3.2 times longer than those who did not have either condition.

Forhan says it is not clear why these patients are more likely to develop infection, but that the findings highlight the need for attentive care among patients with diabetes who undergo bypass surgery.

"We know that wound healing in general is affected by poorly controlled glucose levels, and that adipose (fat) tissue may take longer to recover from trauma. Therefore, as is recommended for all patients, efforts to ensure good glycemic control for patients with diabetes pre- and post-bypass are important," she says.

Forhan also says further research is needed to find ways of preventing infection using evidence-based methods and to determine whether those approaches meet the needs of bypass patients who are moderately to severely obese.

The researchers also intend to investigate the type and locations of people’s infections and whether the chest binders used to aid healing after bypass surgery are supportive enough for obese patients.


Sally Robertson

Written by

Sally Robertson

Sally first developed an interest in medical communications when she took on the role of Journal Development Editor for BioMed Central (BMC), after having graduated with a degree in biomedical science from Greenwich University.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Robertson, Sally. (2018, August 23). Severe obesity may contribute to infection risk after bypass surgery. News-Medical. Retrieved on August 10, 2022 from

  • MLA

    Robertson, Sally. "Severe obesity may contribute to infection risk after bypass surgery". News-Medical. 10 August 2022. <>.

  • Chicago

    Robertson, Sally. "Severe obesity may contribute to infection risk after bypass surgery". News-Medical. (accessed August 10, 2022).

  • Harvard

    Robertson, Sally. 2018. Severe obesity may contribute to infection risk after bypass surgery. News-Medical, viewed 10 August 2022,


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
You might also like...
How does obesity affect the immune system?