An Analysis of Published Data on Thyroxine Turnover in Human Subjects

Data on thyroxine turnover measurements in 726 human subjects were extracted from 30 published papers, supplemented with additional information obtained by correspondence with the 21 groups of authors, and subjected to statistical analysis. The analysis studied the effect of sex, age, pubertal status, weight, height and clinical state on 3 dependent variables-the extrathyroidal thyroxine distribution space V ml, the fractional degradation rate b day-1 and the thyroxine turnover rate H4 μg I/day; for these variables there was sufficient information on 432, 577 and 537 subjects, respectively. Sex and pubertal state showed no significant effect on any of the 3 dependent variables. The space V was found dependent only on weight, independent of height and age, and not influenced by any of the clinical states studied except hepatitis and obesity. The degradation rate b was dependent on age, independent of weight and height, and altered significantly in certain clinical states. The turnover rate H4, being propor...