Objective: Patients with coeliac disease (CD) present anorexia and malnutrition. Leptin is a significant anorexigenic factor, with a close relationship to the body mass index. The aims of this study were to asses serum leptin levels in CD and their possible influence on appetite, as well as to compare and relate leptin with tumor necrosis factor (TNF) activity, which has similar functions.
Methods: Leptin and TNF receptor-1 (TNFr-1) were measured by enzyme-linked immunosorbent assay. Sixty-five serum samples from patients with CD (28 boys and 37 girls) were analyzed. In all patients, small bowel biopsy and anti-endomysium determination were performed simultaneously. Twenty-nine patients presented active CD and 36 were in remission.
Results: Leptin concentrations were reduced in active CD (p = 0.002). In patients in remission, leptin was related to the body mass index (p = 0.001), but this correlation was not found during the active phase of the disease. Contrary to normal differences between sexes, in active CD leptin levels were similar in boys and girls. TNFr-1 was found in all serum samples and levels were statistically higher in patients with active CD (p = 0.0003), suggesting that the TNF system is activated in this disease.
Conclusions: Leptin concentrations were reduced in active CD, but we did not find the usual positive correlation with body mass index and higher concentrations in girls. These results suggest that leptin does not contribute to anorexia and failure to thrive in patients with CD; in contrast, the TNF system might be involved.