Canadian scientists link fat hormone to death from potentially deadly blood infection

Adiponectin found in body fat may hold the key to preventing and treating sepsis

A new Canadian study has found that lower-than-normal levels of a naturally-occurring fat hormone may increase the risk of death from sepsis—an overwhelming infection of the blood which claims thousands of lives each year.

The study by researchers at St. Michael's Hospital and the University of Toronto focused on adiponectin, a hormone secreted by visceral fat surrounding the abdominal organs. The findings were presented this week at the 2009 Clinical Congress of the American College of Surgeons held in Chicago.

Using an animal model designed to mimic what occurs in people with low levels of adiponectin, the scientists observed that:

o Mice with low levels of the hormone were at much greater risk of dying from a blood infection. o Sepsis could be prevented if the animals were given additional adiponectin.

The risk of dying from sepsis after surgery is known to be two-and-a-half to three times higher in people with "metabolic syndrome"—a combination of factors including abdominal obesity, high blood fat composition, high blood pressure, diabetes, and high inflammatory and blood clot indicators. People with these conditions tend to have lower levels of adiponectin which may prime them to greater sepsis related complications.

"We hypothesized that low adiponectin levels might predispose such individuals to develop sepsis and sepsis-related problems," says Dr. Subodh Verma, a cardiac surgeon at St. Michael's Hospital and associate professor of surgery at the University of Toronto who holds the Canada Research Chair in Atherosclerosis. "This initial hypothesis was borne out by our latest research."

Dr. Verma and his colleagues believe the implications of their study are two-fold: first, low adiponectin levels may help predict which patients are vulnerable to sepsis-related inflammation and are at a greater risk of dying from sepsis; second, treatment strategies or approaches that cause an increase in adiponectin levels may lower a person's risk of death from severe sepsis.