Is association between thyroid hormones and gut peptides, ghrelin and obestatin, able to suggest new regulatory relation between the HPT axis and gut?

Background: Ghrelin and obestatin are important appetite- and energy-regulating peptides, secreted by the stomach. These gut peptides and thyroid hormones are involved in metabolism regulation. Although subclinical thyroidism is common, to date, very few studies have been reported about gut hormones in thyroid dysfunction, and their results are controversial. The purpose of this study was to investigate ghrelin and obestatin in patients with subclinical hypo- and hyperthyroidism. Moreover, is association between thyroid hormones and gut peptides able to suggest new regulatory relation between the HPT axis and gut? Materials and methods: The study group included 70 subclinical hypo- and hyperthyroid subjects (in equal groups) and 35 healthy euthyroid controls. Serum values of ghrelin, obestatin, free T3, free T4, thyroid-stimulating hormone and the ratio of ghrelin to obestatin were measured in all participants. Results: Ghrelin and obestatin both decreased in subclinical hypothyroid subjects (320 +/- 81 ng/l and 443 +/- 11.7 ng/l respectively) compared to the control group (487 +/- 110 ng/l and 58.5 +/- 10.3 ng/l, respectively). On the other hand, ghrelin and obestatin both increased in subclinical hyperthyroid subjects (750 +/- 289 ng/l and 71.1 +/- 27.3 ng/l, respectively) compared to the control group. In addition, ghrelin and obestatin showed strong correlations with TSH, FT3 and FT4. Conclusion: This study shows that gut hormones are significantly associated with thyroid hormones. Thus, there may be a cross talk between the HPT axis and gut. We would like to consider new regulatory relation for description of the found data. (C) 2014 Elsevier B.V. All rights reserved.