THE THYROID GLAND AND ITS DISEASES 489 



the metabolism was about 20 per cent below the normal adult level. It is 

 interesting also that he was able to raise the heat production to normal 

 in three and a half days' treatment with thyroid extract. Means and 

 Aub (b) found that in myxedema there is also a diminished basal metab- 

 olism. They found that three cases of untreated myxedema showed a 

 definite reduction below that of normal individuals of the same age and 

 sex. In the treatment of hypothyroidism, doses of from three to four 

 grains of thyroid extract daily should be ample to bring the metabolism 

 to normal in two or three weeks, and doses of from one to two grains 

 daily should usually be sufficient to keep it there. Similarly, the basal 

 metabolism in an untreated cretin and in a case of cachexia strumi- 

 priva showed a marked reduction (Sandiford). Du Bois (1916) found 

 that treatment with thyroid extract raised the heat production and 

 metabolism, while Means and Aub (&) found that the metabolism of all the 

 patients studied during thyroid therapy was readily brought to normal 

 or above, by the administration of thyroid extract. They also regarded 

 the basal metabolism as an index to the effect of treatment and believed, 

 furthermore, that it furnished a far better guide in this respect than 

 does the clinical picture. They found also that cases of cachexia strumi- 

 priva need larger maintenance doses than do those of spontaneous hy- 

 pothyroidism. Finally they believe that in the management of exophthal- 

 mic goiter periodic determinations of the basal metabolism should be quite 

 as much a routine as is the examination of the urine for sugar in diabetes 

 niellitus. Furthermore, in borderline cases the basal metabolism fur- 

 nishes very valuable aid in the differential diagnosis. 



As Boothby has stated: "No factors other than the 'autacoids' have 

 yet been discovered which are known to influence basal metabolism, with 

 the possible exception of the toxins of fevers. Therefore, it seems logical 

 to reverse the accepted theory and, except in the case of infections, to 

 suggest the tentative hypothesis that a variation of the basal metabolism 

 beyond normal limits is due to an abnormality in the secretion of one 

 or more of the endocrin organs. The particular autacoid must then be 

 sought for by characteristic localizing symptoms and by the elimination 

 of those autacoids variations of which produce well-known signs and 

 symptoms." 

 I 



Uses of Metabolic Rate Test 



- 



The metabolic rate test can be used with distinct advantage in the 

 study of thyroid disorders, for example, in the early diagnosis of hy- 

 perthyroidism, in which case an early increase in the metabolic rate to- 

 gether with other clinical signs and symptoms would be very suggestive 

 indeed. The measurement of the heat production gives a very accurate 

 index of the severity of the case and of the degree of hyperthyroidism 



