Brown Adipose Tissue Response to Cold Stimulation Is Reduced in Girls With Autoimmune Hypothyroidism Law, James M. Muros Molina, José Joaquín Autoimmune Brown adipose tissue Cold-induced thermogenesis Infrared thermography Thyroid hormones The interaction between thyroid status and brown adipose tissue (BAT) activation is complex. We assessed the effect of autoimmune hypothyroidism (ATD) in female children on BAT activation, measured using infrared thermography. Participants with ATD had lower resting (hypothyroid, 34.9 +- 0.7°C; control, 35.4 +- 0.5°C; P = 0.03) and stimulated (hypothyroid, 35.0 +- 0.6°C; control, 35.5 +- 0.5°C; P = 0.04) supraclavicular temperatures compared with controls, but there was no difference between groups in the temperature increase with stimulation. BAT activation, calculated as the relative temperature change comparing the supraclavicular temperature to a sternal reference region, was reduced in participants with ATD (hypothyroid, 0.1 +- 0.1°C; control, 0.2 +- 0.2°C; P = 0.04). Children with ATD were frequently biochemically euthyroid due to replacement therapy, but, despite this, increased relative supraclavicular temperature was closely associated with increased TSH (r = 0.7, P = 0.01) concentrations. Girls with ATD had an attenuated thermogenic response to cold stimulation compared with healthy controls, but, contrary to expectation, those with suboptimal biochemical control (with higher TSH) showed increased BAT activation. This suggests that the underlying disease process may have a negative effect on BAT response, but high levels of TSH can mitigate, and even stimulate, BAT activity. In summary, thyroid status is a complex determinant of BAT activity in girls with ATD. 2020-02-12T12:22:16Z 2020-02-12T12:22:16Z 2019-10-11 info:eu-repo/semantics/article Law, J. M., Morris, D. E., Astle, V., Finn, E., Muros, J. J., Robinson, L. J., ... & Budge, H. (2019). Brown adipose tissue response to cold stimulation is reduced in girls with autoimmune hypothyroidism. Journal of the Endocrine Society, 3(12), 2411-2426. http://hdl.handle.net/10481/59611 10.1210/js.2019-00342 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ info:eu-repo/semantics/openAccess Atribución-NoComercial-SinDerivadas 3.0 España Oxford University Press