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

Abstract

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.

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  • Publisher Full Text
  • Authors

    Ockenga J, Valentini L, Schuetz T, Wohlgemuth F, Glaeser S, Omar A, Kasim E, duPlessis D, Featherstone K, Davis JR, Tietge UJ, Kroencke T, Biebermann H, Köhrle J, Brabant G

    Source

    The Journal of clinical endocrinology and metabolism 97:2 2012 Feb pg 535-42

    MeSH

    Adult
    Bile Acids and Salts
    Biopsy
    Calorimetry, Indirect
    Energy Metabolism
    Female
    Humans
    Liver Cirrhosis
    Longitudinal Studies
    Male
    Middle Aged
    Nutritional Status
    Portasystemic Shunt, Transjugular Intrahepatic
    Thyroid Function Tests
    Thyroid Gland

    Pub Type(s)

    Journal Article
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    22162464