STUDIES OF THE HUMAN THYROID FUNCTION, MEASURED BY RADIO-IODINE, AND ITS RELATION TO THE BASAL METABOLIC RATE

Abstract

A method of estimating thyroid function with carrier-free radio-iodine which provides an arbitrary numerical scale of thyroid activity is described. It is suitable for investigating borderline thyroid dysfunction. The results on over 500 psychiatric patients are given in the form of histograms, and arbitrary limits of normality are defined on the basis of these results. While there is usually a correlation between the tracer method and the basal metabolic rate, cases exist in which increased thyroid activity, determined by the radio-active method, is associated with normal or subnormal b.m.r. and vice versa. This is explained as a disturbance of the sensitivity of body tissues to thyroid hormone. The significance of under-sensitivity to thyroid hormone and related problems is discussed, and the importance of considering peripheral sensitivity of the tissues of the body in evaluating an abnormal thyroid activity is emphasized.