Obesity paradox in survival from sepsis

In a study of 1,404 Medicare beneficiaries, heavier patients were more likely to survive sepsis, a life-threatening infection that can lead to a stay in a hospital's intensive care unit.

The findings, published in the August issue of Critical Care Medicine, raise interesting questions about how obesity impacts the body's response to infection. Obesity is most often connected with worse, not better, health outcomes.

"Physicians expect obese patients to do poorly and this belief can affect the care and counseling they provide to patients and their families," says lead author Hallie C. Prescott, M.D., a pulmonary and critical care medicine clinical lecturer at the U-M Health System. "Our study indicates obese sepsis patients actually have lower mortality and similar functional outcomes as normal weight patients."

The focus of the study was to investigate the association of body mass index to survival, health care use and functional deficiencies following a severe sepsis hospitalization.

The last objective was selected because of the value patients place on living and functioning independently.

The incidence of sepsis has doubled in the past 15 years leading to an increased focus on research and Medicare spending. Severe sepsis causes a million hospitalizations yearly among Medicare beneficiaries.

These hospitalizations cost more than $16 billion annually, which is roughly 4 times the cost of hospitalizations for heart attacks. Half of patients hospitalized with severe sepsis die within a year.

The patients who survive often become debilitated during their hospital stay and need to spend time in a rehabilitation facility.

"Obese patients who survive their sepsis hospitalization use more health care resources and require more Medicare spending -- but this apparent increase in resource use is a result of living longer, not increased use per day alive," says senior author Theodore Iwashyna, M.D., Ph.D., assistant professor of internal medicine at the U-M Health System.

Authors note there are many health benefits to maintaining a normal weight, but the findings suggest that excess weight may cause the body to respond differently to critical illness. A better understanding of this difference may help health care providers improve care for all patients with sepsis and other critical illnesses.