Hyperthyroidism. 



119 



the cases of Grave's disease than in the controls. This may give 

 an erroneous impression however, as it has been suggested that 

 the abnormal cases should be figured on the basis of what the rise 

 in calories would have amounted to had the patient's metabolic 

 rate been normal. When figured in this way the two curves are 

 very much alike. It seems likely therefore that the specific 

 dynamic action of carbohydrates is much the same in both normal 

 controls and cases of hyperthyroidism. 



It seems fairly plausible from an analysis of the blood sugar and 

 respiratory quotient curves that the hyperglycemia and low 

 sugar tolerance so frequently found in Grave's disease are not 

 due to any inability of the tissues to burn carbohydrate, but very 

 probably to a decreased ability of the liver to store it. This is 

 further substantiated by approximate calculations of the grams of 

 carbohydrate burned. If 15 per cent, of the calories are assumed 

 to have been derived from protein and the rest apportioned to 

 carbohydrate and fat according to the respiratory quotient (table 

 of Zunst and Schumburg) and the grams of carbohydrate metab- 

 olized, then figured from this, it will be seen that the increase 

 in the amount of carbohydrate burned is very great in the hyper- 

 thyroids and very slight in the normals — that is, the normals are 

 apparently storing carbohydrate while the hyperthyroids, stimu- 

 lated by the carbohydrate plethora, are burning it. This fits in 

 very well with the work of Cramer and his collaborators in England 

 and Kuriyama in this country, who have found that thyroid fed 

 animals (white mice and rabbits) on high carbohydrate diets 

 showed only traces of glycogen in the liver, while control animals 

 showed normal amounts. This would account for the low fasting 

 respiratory quotient in thyroid disease, and would explain a clinical 

 observation that has been noticed by some observers — namely, 

 that it is very easy to produce acidosis in a hyperthyroid. One case 

 in point, on the surgical side of the Presbyterian Hospital (History 

 No. 30699), who was in for the treatment of hyperthyroidism and 

 who had glycosuria on a regular diet, went into severe acidosis on 

 being put on the standard strict diet (10 Carbohydrate — 100 

 Protein — 120 Fat) in an attempt to clear up the glucosuria. 



In all the eight cases of Grave's disease studied, there was an 

 original increase in the total metabolism of 30 per cent, or over; 



