Plasma bile acids are associated with energy expenditure and thyroid function in humans.

J Clin Endocrinol Metab 2012 Feb 7;97(2):535-42. Epub 2011 Dec 7.

Department of Gastroenterology, Hepatology, Endocrinology, and Nutrition, Klinikum Bremen Mitte, St. Juergen Strasse 1, D-28177 Bremen, Germany.

Background/aims: Animal studies implicate a role of bile acids (BA) in thyroid-regulated energy expenditure (EE) via activation of the TGR-5/adenylate cyclase/deiodinase type 2 pathway. Here we investigated these possible associations in humans.

Methods: EE, BA, and thyroid hormone status were assessed in 10 healthy subjects and eight patients with liver cirrhosis at baseline and after oral nutrition. In cirrhosis, blood was additionally sampled from the mesenteric vein and the radial artery.

Results: At baseline, BA and EE related positively (r = 0.648, P = 0.048 in healthy subjects; r = 0.833, P = 0.010 in cirrhosis; r = 0.556, P =0.017 in all), with the highest correlation with deoxycholic acid levels. The respiratory quotient associated negatively to baseline BA (all, r = -0.639, P = 0.004). Postprandially, serum TSH decreased in both groups (P < 0.05 each). In cirrhosis, the decrease of TSH after 60 min correlated to the meal-stimulated BA increase (r = -0.762, P = 0.028). To assess the mechanism involved, we studied a single human TSHoma and TαT1 mouse thyrotrope cells. In TSHoma cells, TGR-5 was predominantly expressed cytoplasmically, and in vitro stimulation with BA did not substantially alter cAMP or deiodinase type 2.

Conclusions: Our data support a role of BA in human energy metabolism and in thyroid hormone control. Even though no convincing response to BA was demonstrated in TSHoma and TαT1 cells, the TSH decrease after a nutritional challenge suggests an interaction of BA on the set point of the thyroid axis.

Download full-text PDF

Source
http://dx.doi.org/10.1210/jc.2011-2329DOI Listing
February 2012
33 Reads

Publication Analysis

Top Keywords

energy expenditure
8
thyroid hormone
8
tshoma tαt1
8
bile acids
8
healthy subjects
8
decrease tsh
4
cirrhosis decrease
4
005 cirrhosis
4
groups 005
4
serum tsh
4
tsh decreased
4
decreased groups
4
tsh min
4
meal-stimulated increase
4
assess mechanism
4
mechanism involved
4
involved studied
4
0028 assess
4
-0762 0028
4
correlated meal-stimulated
4

Similar Publications