TY - JOUR
T1 - Activation of brown adipose tissue in hypothyroidism
AU - Lapa, Constantin
AU - Maya, Yoshifumi
AU - Wagner, Martin
AU - Arias-Loza, Paula
AU - Werner, Rudolf A.
AU - Herrmann, Ken
AU - Higuchi, Takahiro
PY - 2015/10/3
Y1 - 2015/10/3
N2 - Background Brown adipose tissue (BAT) attracts growing interest as a potential therapeutic target for obesity and diabetes. Hyperthyroidism is well-known to increase BAT activity, but the role of hypothyroidism is controversial. We aimed to investigate the association between different thyroid hormone (TH) states and BAT activity.Methods FDG-PET studies were retrospectively evaluated in thyroid cancer patients after total thyroidectomy both at euthyroidism during TH replacement or at hypothyroidism after TH cessation. Serum TH levels were compared between patients with active BAT and control patients with non-active BAT matched for age, gender, and body mass index. Additionally, animal experiments with controls (n = 5) and hypothyroid rats (n = 5) were performed.Results Out of 124 patients, 6 patients with active BAT were identified. These patients showed significantly higher thyroid-stimulating hormone (TSH) levels than matched controls (P < 0.05). In animal experiments, all hypothyroid animals showed BAT activation at room temperature (24 °C), whereas controls did not (P < 0.001). Increased BAT activity was also confirmed by increased expression of UCP-1 and D2.Conclusions Increased BAT metabolism appears to be related with hypothyroidism, which might be the result of a feedback mechanism to maintain body temperature in a state of reduced basal thermogenesis. Future research needs to explore the underlying mechanistic and biological implications.Key MessagesIncreased brown adipose tissue (BAT) metabolism appears to be related with hypothyroidism, which might be the result of a feedback mechanism to maintain body core temperature in a state of reduced basal thermogenesis.
AB - Background Brown adipose tissue (BAT) attracts growing interest as a potential therapeutic target for obesity and diabetes. Hyperthyroidism is well-known to increase BAT activity, but the role of hypothyroidism is controversial. We aimed to investigate the association between different thyroid hormone (TH) states and BAT activity.Methods FDG-PET studies were retrospectively evaluated in thyroid cancer patients after total thyroidectomy both at euthyroidism during TH replacement or at hypothyroidism after TH cessation. Serum TH levels were compared between patients with active BAT and control patients with non-active BAT matched for age, gender, and body mass index. Additionally, animal experiments with controls (n = 5) and hypothyroid rats (n = 5) were performed.Results Out of 124 patients, 6 patients with active BAT were identified. These patients showed significantly higher thyroid-stimulating hormone (TSH) levels than matched controls (P < 0.05). In animal experiments, all hypothyroid animals showed BAT activation at room temperature (24 °C), whereas controls did not (P < 0.001). Increased BAT activity was also confirmed by increased expression of UCP-1 and D2.Conclusions Increased BAT metabolism appears to be related with hypothyroidism, which might be the result of a feedback mechanism to maintain body temperature in a state of reduced basal thermogenesis. Future research needs to explore the underlying mechanistic and biological implications.Key MessagesIncreased brown adipose tissue (BAT) metabolism appears to be related with hypothyroidism, which might be the result of a feedback mechanism to maintain body core temperature in a state of reduced basal thermogenesis.
KW - Brown adipose tissue
KW - PET/CT
KW - TSH
KW - hypothyroidism
KW - thyroid hormone
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U2 - 10.3109/07853890.2015.1085126
DO - 10.3109/07853890.2015.1085126
M3 - Article
C2 - 26513396
AN - SCOPUS:84948714192
VL - 47
SP - 538
EP - 545
JO - Annales medicinae experimentalis et biologiae Fenniae
JF - Annales medicinae experimentalis et biologiae Fenniae
SN - 0785-3890
IS - 7
ER -