Stokholm K H, Lindgreen P
Int J Obes. 1982;6(6):573-8.
Serum concentrations of free triiodothyronine (T3) and total T3 were measured in 25 grossly obese patients with constant body weight and no dietary restrictions. The results were compared with serum free T3 and total T3 in 55 non-obese volunteers matched in sex and age. Median serum concentration of free T3 (4.5 pmol/l) and total T3 (1.80 nmol/l) in the obese patients were not significantly (P greater than 0.10) different from free T3 (4.6 pmol/l) and total T3 (1.84 nmol/l) in the normal persons. The risk of type II error (P beta) for overlooking a possible, true difference between obese and normal persons were estimated. If there is a difference in the mean value of free T3 then it is less than 0.5 pmol/l (P beta less than 0.05), corresponding to 12 per cent of the mean value of free T3 in the normal persons. If there is a difference in the mean value of total T3 then it is less than 0.21 nmol/l (P beta less than 0.01) corresponding to 11 per cent of the mean value of total T3 in the normal persons. The caloric and carbohydrate intakes were estimated in 17 of the obese patients and showed no significant correlations with serum free or total T3. The study indicates that the thyroid function per se is normal in obesity and adapts to increasing body weight by enhanced production of thyroid hormones and thereby sustaining a normal serum concentration of free T3.
在25名体重恒定且无饮食限制的严重肥胖患者中测量了血清游离三碘甲状腺原氨酸（T3）和总T3的浓度。将结果与55名年龄和性别相匹配的非肥胖志愿者的血清游离T3和总T3进行比较。肥胖患者血清游离T3的中位数浓度（4.5 pmol/l）和总T3（1.80 nmol/l）与正常人的游离T3（4.6 pmol/l）和总T3（1.84 nmol/l）相比，差异无统计学意义（P大于0.10）。估计了忽略肥胖者与正常人之间可能存在的真实差异的II类错误风险（Pβ）。如果游离T3的平均值存在差异，那么该差异小于0.5 pmol/l（Pβ小于0.05），相当于正常人游离T3平均值的12%。如果总T3的平均值存在差异，那么该差异小于0.21 nmol/l（Pβ小于0.01），相当于正常人总T3平均值的11%。对17名肥胖患者的热量和碳水化合物摄入量进行了估计，结果显示与血清游离或总T3无显著相关性。该研究表明，肥胖本身甲状腺功能正常，通过增加甲状腺激素的产生来适应体重增加，从而维持血清游离T3的正常浓度。
