Circulating Ghrelin Levels and Obestatin/Ghrelin Ratio as a Marker of Activity in Ulcerative Colitis

BACKGROUND/AIMS: Ghrelin levels are known to increase in patients with ulcerative colitis (UC), but serum obestatin levels in UC patients are not well elucidated. The aim of this study was to examine the relationship between serum ghrelin and obestatin levels and disease activity in UC patients. METHODS: The serum ghrelin and obestatin levels were measured in 21 UC patients (12 with active disease and 9 in remission) using enzyme-linked immunosorbent assay. The relationship between the circulating levels of these 2 hormones and disease activity was analyzed. The colonic mucosal mRNA expression of ghrelin and obestatin was measured by quantitative reverse transcription polymerase chain reaction. RESULTS: The mean serum ghrelin values were significantly higher in patients with active disease than in patients with remission (1370.6±404.3 vs. 783.5±235.3 pg/mL, P=0.001). Colonic mucosal mRNA expression of ghrelin was also significantly higher in patients with active disease than in patients in remission (0.805±0.214 vs. 0.481±0.356, P=0.018). However, the mean serum obestatin levels and colonic mucosal mRNA expression of obestatin were not significantly different between both groups. The circulating obestatin/ghrelin ratio was significantly lower in patients with active UC than in patients in remission (0.32±0.08 vs. 0.58±0.20, P=0.001). CONCLUSIONS: The serum ghrelin levels and the obestatin/ghrelin ratio were related to the activity of UC, but serum obestatin was not related to activity of UC. The ghrelin levels and the obestatin/ghrelin ratio could serve as activity markers in patients with UC.