Visceral Fat Hormone Could Protect Against Life-Threatening Sepsis

Low levels of adiponectin, a hormone naturally found in the fat that surrounds the abdominal organs, has been linked to death related to sepsis, according to a new study.

Researchers at St. Michael's Hospital (Toronto, ON, Canada) and the University of Toronto (ON, Canada) conducted an animal model study to mimic what occurs in patients who have low adiponectin levels, who have been found to be at high risk for developing sepsis after surgery, due to underlying diabetes, morbid obesity, or metabolic syndrome (a combination of factors including abdominal obesity, high blood fat composition, high blood pressure, diabetes, and high inflammatory and blood clot indicators). The risk of septic-related mortality is two-and-a-half to three times higher in such patients. The researchers hypothesized that low adiponectin levels might predispose individuals to develop sepsis and sepsis-related problems, due to recent research that suggested the hormone might be a common link between inflammation, diabetes, and metabolic syndrome.

The study results showed that in fact low levels of the hormone placed the animals at a profoundly high risk of death from a septic insult; the study findings also revealed that sepsis could be prevented by giving the hormone to the animals. The investigators are now seeking approval from the national health care system of Canada to begin a clinical trial that will administer a purified form of adiponectin to patients who are in the early stages of sepsis. The study was presented at the 2009 Clinical Congress of the American College of Surgeons, held during October 2009 in Chicago (IL, USA).

"The implications are two-fold; one is that adiponectin may serve as an independent predictor of developing sepsis-related inflammation and vascular dysfunction as well as increased mortality from sepsis,” said lead author Subodh Verma, M.D., Ph.D., a cardiac surgeon. "The other is that treatment strategies or approaches that cause an increase in adiponectin levels may protect against sepsis-related mortality.”

Adiponectin modulates a number of metabolic processes, including glucose regulation and fatty acid catabolism. It is exclusively secreted from adipose tissue into the bloodstream and is very abundant in plasma. Levels of the hormone are inversely correlated with body fat percentage in adults, while the association in infants and young children is more unclear. The hormone plays a role in the suppression of the metabolic derangements that may result in type 2 diabetes, obesity, atherosclerosis, nonalcoholic fatty liver disease (NAFLD), and is an independent risk factor for metabolic syndrome.

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St. Michael's Hospital
University of Toronto