684 METABOLISM 



to the production of ketones when carbohydrate combustion is de- 

 pressed. Fundamentally, therefore ketosis in diabetes is due to the 

 same cause as in starvation — namely, an improper adjustment between 

 the metabolisms of fat and carbohydrate. 



Bearing these principles in mind, it is easy to see how the intensity 

 of acidosis which develops during starvation will depend upon the re- 

 lative metabolism of carbohydrate, on the one hand, and of fat and 

 protein, on the other; it will therefore depend on the amounts of these 

 foodstuffs which have been stored in the organism, and this again will 

 depend on the nature of the diet previous to the starvation period. For 

 the first few days following entire abstinence from food in a healthy, 

 well-nourished individual, very few if any ketones will be excreted in 

 the urine, because the carbohydrate stored in the body as glycogen has 

 sufficed during this time to maintain the proper proportion between fat 

 and carbohydrate. Afterwards, however, their appearance is to be ex- 

 pected, because the glycogen stores become exhausted long before those 

 of fat. If starvation is still further prolonged, a stage will come when 

 the. fat. as well as the carbohydrate, is used up so that the organism has 

 now to subsist on protein alone. When this stage arrives, the ketones 

 will diminish, for, although they might be derived from certain of the 

 amino acids, yet this does not actually occur, because a large part of the 

 protein molecule (nearly half) also becomes changed into glucose, which 

 by burning, as above explained, prevents the formation of ketones from 

 the other part of the molecule. For the same reasons, marked acidosis 

 will not be expected to occur during any stage of starvation in lean 

 persons, who from the start must utilize mainly their stored protein to 

 supply the fuel upon which to live. 



In diabetes exactly the same principles apply, but to an organism in 

 which the ability to metabolize carbohydrate has been depressed, so that 

 "the maximum rate at which dextrose can be oxidized is fixed at some 

 level which is absolutely lower than in health." 30 Therefore, since a cer- 

 tain proportionality must exist between the rates of combustion of fat 

 and carbohydrate, the diabetic can thoroughly oxidize less fat; in other 

 vords, an amount of fat which could readily be burned in a healthy body 

 is improperly burned by the diabetic, and ketones and their acids ac- 

 cumulate. 



Starvation Treatment. — "In order to check a diabetic acidosis, it is 

 necessary to restore the proper ratio of fatty acid to glucose oxidation, 

 which can best be done by starvation, rest in bed and warmth. But this 

 treatment may not at first suffice, because wc have to deal not only with 

 the acidosis bodies derived from fat. but with those which can be derived 

 from protein on account of the diabetic organism having lost the power 



