Serum Lipoids and Proteins in Hyperthyroidism 1

Abstract

It has been stated frequently that the level of serum cholesterol is as valuable an index of hyperthyroid activity as the basal metabolic rate. An examination of the literature, however, reveals controversial material to support this dictum. The present study was undertaken to determine how closely the level of serum cholesterol is related to the degree of thyroid activity and whether it is a useful criterion in the diagnosis of hyperthyroidism. It was thought of importance also to know if changes in the level of serum cholesterol after the administration of iodine might help in diagnosis in those questionable hyperthyroid patients whose basal metabolic rates do not respond to the ingestion of Lugol's solution. In addition to the cholesterol, basal metabolic rates, serum fatty acids, phosphatides and proteins of 65 patients with symptoms of hyperthyroidism have been determined at frequent intervals to learn: (1) whether there is an inverse relationship between basal metabolic rate and serum cholesterol, lipoid phosphorus, fatty acids and proteins; (2) if these serum constituents increase when the basal metabolic rate falls after the administration of iodine; and (3) if thyroidectomy always increases these components. The data on only 43 patients are presented in the tables because the other 22 patients were not completely studied. There were about 430 samples of blood sera in which the three lipoid fractions and proteins were determined during the 3 or more years that many of the patients have been followed.Hurxthal, Hunt and co-workers have studied the largest group of patients (23,24,25,26,38). Although they have employed a cholesterol colorimetric method described by Bloor in 1922, their results are reliable because they have devoted considerable attention to normal values. They have placed the low limit of normal for their method at 120 mgm. per cent, and the high limit at 300 1This work was aided in part by a grant from the Knight Fund, Yale University School of Medicine. mgm. per cent (26). In the study of patients with hyperthyroid disease these authors have found cholesterol values in a large majority of patients which were close to their low limit of normal. The rest of the values were distributed about equally on both sides of this figure (23). These authors have considered the possible effect of malnutrition on the serum cholesterol and have decided that it is of minor importance (23).They conclude that serum cholesterol is low in hyperthyroidism and that there is a relation between the severity of the disease and the level of cholesterol (23). Recent studies by Boyd indicate that total lipoids and phospholipids, as well as cholesterol, tend to be low in hyperthyroidism (7,8,9,10,11). Thus these recent studies on a large number of patients support the view that severe degrees of hyperthyroidism are usually associated with low levels of serum cholesterol (4,16,41,45,47).It is, however, probable that there are a considerable number of patients with severe hyperthyroidism who do not have low serum choles...

Blood Iodine in Patients With Thyroid Disease 1

“…The serum cholesterols were 124 and 141 milligrams per cent. These values approach the low levels in clear-cut hyperthyroidism (19).…”

The Significance of Serum Cholesterol in Thyroid Disease 1

“…The solid circles (21), that it is impossible by such methods as this to demonstrate that hyperthyroidism affects serum cholesterol. The latter is only a negative aid in the diagnosis of hyperthyroidism.…”

The Interrelations of Serum Lipids in Patients With Thyroid Disease 1

“…In hyperthyroidism, cholesterol and lipid phosphorus are reduced (3). Again, however, the actual concentration of cholesterol in the serum is not closely correlated with the severity of the hy- concentration of cholesterol.…”

“…Man, Gildea, and Peters (1,3) found a correlation between cholesterol and total fatty acids, but this was less exact than the correlation between cholesterol and lipid phosphorus. Since most of the fatty acid of serum belongs to cholesterol esters and phospholipids, there would have to be some correlation between cholesterol and fatty acids.…”