Fig 1.
Consort 2010 flow chart.
Fig 2.
Schematic representation of study measurements after total thyroidectomy in the Maastricht University Medical Centre.
Blue arrows indicate moment of study measurements. FT4 indicates free thyroxine, TSH indicates thyroid-stimulating hormone, levothyroxine treatment indicates pharmacological levothyroxine suppletion that suppresses endogenous TSH. I131 indicates radioactive iodine, used for radioactive ablation therapy of thyroid gland remnants after thyroid gland resection for well-differentiated thyroid carcinoma. I124 indicates a proton-rich isotope of iodine used as a radiochemical for determination of thyroid gland remnants after thyroid gland resection for well-differentiated thyroid carcinoma.
Table 1.
Subject characteristics (N = 10).
Fig 3.
BAT activity, BMR and NST before and after levothyroxine therapy.
Brown adipose tissue (BAT) activity before and after levothyroxine substitution therapy. (A) Basal metabolic rate (BMR) in joules per minute. (B) Non-shivering thermogenesis (NST) before and after levothyroxine replacement therapy. (C) BAT activity in Mean Standard Uptake Values (SUV mean) before and after levothyroxine therapy. Subject indicated with X is also depicted in Fig 2D and 2E. (D) Transversal CT (top) and PET/CT fusion (bottom) slice of the supraclavicular region demonstrating 18F-FDG-uptake in BAT locations (white arrows) after cold exposure in hypothyroid state. (E) Transversal CT (top) and PET/CT fusion (bottom) slice of the supraclavicular region demonstrating 18F-FDG-uptake in BAT locations (white arrows) after cold exposure in subclinical hyperthyroid state.
Table 2.
Skin perfusion, blood pressure, and body temperature under thermoneutral conditions and during mild cold exposure, before and after levothyroxine substitution (N = 10.)