Alteration in Elemental Body Composition in Thyroid Disorders1

Abstract

Recent developments in the technique of total-body neutron activation analysis (TBNAA) have made it possible for the first time to measure precisely total body levels of calcium, phosphorous, sodium and chlorine in human subjects. This technique has been employed here to evaluate the degree of skeletal demineralization in patients with thyroid disorders both prior to and following the initiation of therapeutic regimes. The loss of Ca in white thyrotoxic patients was found to average 9.4% in terms of expected normal values. The Ca and P levels of 2 black patients with thyrotoxicosis were within the range of their expected normal values. The expected normal Ca values (CaP) were empirically derived from the height and potassium levels of 14 normal subjects. Following the institution of a therapeutic program, whether with drugs, surgery or 131I treatment, body Ca increased 8.4% on the average in the first 9 months. At the same time Na decreased along with the P/Ca ratio, and lean body mass (measured by K) and...