Abstract

Thyroid hormones play an important role in the modulation of energy metabolism by regulating the rate of thermogenesis, i.e. the amount of heat produced to maintain the stable core temperature of the organism. Clinically, hypo- and hyperthyroidism are associated with major changes of thermoregulation and energy expenditure. Nevertheless, the ability of thyroid hormones in regulating the temperature and energy expenditure in response to changes of temperature is poorly understood in humans. In a collaborative randomized, cross-over study, we are now analyzing the changes in the thyroid hormones, energy expenditure and stress hormones in response to exposure to mild changes in environmental temperature using a metabolic chamber. Changes in skin and core temperature, heart rate, energy expenditure, circulating thyroid hormones, ACTH, cortisol, catecholamines, free fatty acids and glucose are being monitored. The results gathered from this study are expected to provide a comprehensive insight into the mechanism(s) regulating the energy metabolism in response to mild cold. They might lead to the characterization of a population of subjects who are requiring excessive energy expenditure to prevent hypothermia upon cold exposure.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
Clinical Center (CLC)
Type
Intramural Research (Z01)
Project #
1Z01CL010305-10
Application #
7733630
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
10
Fiscal Year
2008
Total Cost
$16,720
Indirect Cost

  Institution

Name
Clinical Center
Department
Type
DUNS #
City
State
Country
United States
Zip Code

  Publications

Celi, Francesco S; Zemskova, Marina; Linderman, Joyce D et al. (2009) The pharmacodynamic equivalence of levothyroxine and liothyronine. A randomized, double blind, cross-over study in thyroidectomized patients. Clin Endocrinol (Oxf) :
Bowen, Raffick A R; Vu, Chi; Remaley, Alan T et al. (2007) Differential effect of blood collection tubes on total free fatty acids (FFA) and total triiodothyronine (TT3) concentration: a model for studying interference from tube constituents. Clin Chim Acta 378:181-93
Eisenhofer, Graeme; Lenders, Jacques W M; Goldstein, David S et al. (2005) Pheochromocytoma catecholamine phenotypes and prediction of tumor size and location by use of plasma free metanephrines. Clin Chem 51:735-44
Bowen, Raffick A R; Chan, Yung; Ruddel, Mark E et al. (2005) Immunoassay interference by a commonly used blood collection tube additive, the organosilicone surfactant silwet L-720. Clin Chem 51:1874-82
Bowen, Raffick A R; Chan, Yung; Cohen, Joshua et al. (2005) Effect of blood collection tubes on total triiodothyronine and other laboratory assays. Clin Chem 51:424-33
Eisenhofer, Graeme; Goldstein, David S; Sullivan, Patricia et al. (2005) Biochemical and clinical manifestations of dopamine-producing paragangliomas: utility of plasma methoxytyramine. J Clin Endocrinol Metab 90:2068-75
McGriff, Nayahmka J; Csako, Gyorgy; Gourgiotis, Loukas et al. (2002) Effects of thyroid hormone suppression therapy on adverse clinical outcomes in thyroid cancer. Ann Med 34:554-64
Csako, G; McGriff, N J; Rotman-Pikielny, P et al. (2001) Exaggerated levothyroxine malabsorption due to calcium carbonate supplementation in gastrointestinal disorders. Ann Pharmacother 35:1578-83
Collins, M T; Remaley, A T; Csako, G et al. (2000) Increased levothyroxine requirements presenting as ""inappropriate"" TSH secretion syndrome in a patient with nephrotic syndrome. J Endocrinol Invest 23:383-92
Csako, G; Byrd, D; Wesley, R A et al. (2000) Assessing the effects of thyroid suppression on benign solitary thyroid nodules. A model for using quantitative research synthesis. Medicine (Baltimore) 79:26-Sep

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