Effects of total fasting in obese women. I. Response of the thyroid.
The values of serum T4, T3, T4/T3, RT3U, FT4I, PBI, ATR, TSH, 132I uptake and antibodies against thyreoglobulin were estimated in non-obese, healthy women and in obese women with a stabile body weight on total fasting of 14 days. Obesity with no dietary restriction compared with normal controls was accompanied by a tendency to higher serum levels of T4 and T3 and prolonged ATR. Other indicators of thyroid function remained unchanged. Total fasting led to a decrease of serum T3 and to an increase of FT4I and RT3U. The remaining tests were unchanged. These results are conform with a decreased transformation of T4 into T3 in the periphery. The participation of the hypothalamus and hypophysis to adaptation of the thyroid to fasting was discussed.
D005215:Fasting; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D009765:Obesity / Q000503:physiopathology*; D012737:Sex Factors; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000503:physiopathology*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D007457:Iodine Radioisotopes; D014284:Triiodothyronine; D013974:Thyroxine