Effect of weight loss and the inflammatory response on leptin concentrations in gastrointestinal cancer patients

Animal research suggests that leptin may have an important role in the regu lation of energy balance. The role of leptin in the progressive involuntary weight loss associated with cancer in humans is of considerable interest, However, such studies are limited. In this study, we compared circulating l eptin concentrations in gastrointestinal cancer patients and weight loss (n = 27) with those of healthy subjects (n = 27), The effect of the presence of an inflammatory response on leptin concentrations was also examined. The re were significantly lower leptin concentrations in male (median, 2.4 mu g /liter; range, <0.5-6.0 mu g/liter) and female (median, 3.4 mu g/liter; ran ge, <0.5-9.8 mu g/liter) cancer patients than there,were in male (median, 6 .5 mu g/liter; range, 3.1-10.9 mu g/liter) and female (median, 18.7 mu g/li ter; range, 8.0-31.5 mu g/liter) healthy subjects (P < 0.001), However, the leptin concentrations in both patients and normal subjects were related to the predicted percentage of body fat (r = 0.731; P < 0.001), Circulating l eptin concentrations in the cancer patients mere not altered by the presenc e of an inflammatory response. These results suggest that cancer anorexia/c achexia is not due to a simple dysregulation of leptin production.