Clinical Newswire, March 12, 2010 (Munich, Germany) - A group of researchers at the Department of Surgery of the University of Florida, USA, have discovered an attenuation of the early cytokine response to severe blunt injury in obese patients. The finding, presented at the 8th World Congress on Trauma, Shock, Inflammation and Sepsis (TSIS 2010), contradicts the previous assumption that the increased risk of multiple organ failure (MOF) following injury in obese patients was connected to elevated levels of inflammatory cytokines.
Following blunt injury, many pro-inflammatory cytokines are released. These can result in systemic inflammatory response syndrome (SIRS), which can in turn precipitate organ failure. Several early cytokines have been identified as predictive markers for MOF, with high initial response associated with increased risk of later MOF.
Obesity and inflammatory cytokines are closely linked. Studies of adipose tissue in obese subjects reveal increased levels of inflammatory cell adhesion and profound differences in cytokine expression compared with the adipose tissue of people of normal weight. A state of chronic inflammation is thought to be generated in the adipose tissue of obese individuals.
Researchers Robert Winfield MD and colleagues hypothesised that following severe blunt trauma, obese patients would show an elevated cytokine response compared with those of normal weight. Prospective data from the “Inflammation and the Host Response to Injury” database were retrospectively reviewed. A total of 74 adult blunt trauma patients, of whom 40 were obese, were included in the analysis. Aside from a slight difference in mean age, the severity of injury and all other parameters were similar between obese and non-obese patients.
Significant reductions in IL-10 were seen in obese patients compared with those of normal BMI on days 0 and 4. Reduced expression of IFN-γα on day 4, and MIP-1α, TNF-α, and IL-1β on day 1 was seen in obese patients (all P<0.05). However, obese patients had numerically higher mean MOF scores and a significantly higher cardiac component to MOF scores than normal patients (2.9 vs. 2.4, P = 0.031).
These results demonstrate that whilst an elevated baseline pro-inflammatory cytokine profile is observed in obese patients, the early cytokine response to severe blunt injury becomes attenuated. The current findings generate a paradox in that despite a lowered early cytokine response compared to patients with normal BMI, obese subjects with severe blunt injury nevertheless show higher levels of MOF.
“Alternate mechanisms may be responsible for increased multiple organ failure development in this high-risk population,” noted Dr Winfield.
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