450 V. BLOOD LIPIDS 



reason for this is that these acids react with sodium bicarbonate, with the 

 consequent production of carbonic acid and of the alkali salts of the ketone 

 body acids. The latter are excreted in the urine, with a resultant loss of 

 fixed base from the blood. The carbonic acid formed is largely broken 

 down to water and carbon dioxide; the latter is excreted in the expired air. 



During the constant and steady production of the ketone body acids in- 

 herent in the diabetic syndrome, additional amounts of sodium bicarbonate 

 continue to be used for neutralization; a progressive decrease in the C0 2 - 

 combining power of the blood occurs. As the supply of bicarbonate is de- 

 pleted, a larger proportion of the acid is neutralized by ammonia. The 

 ammonium hydroxide, required for this reaction, is made available at the 

 expense of the urea. Moreover, as the acidosis becomes more severe, 

 the body tends to secrete a more acid urine, in which a greater proportion 

 of the ketone body acids is eliminated in the form of free acids, rather than 

 as their sodium, potassium, or ammonium salts. 



The requirement for fat is augmented both in fasting and in diabetes 

 mellitus. However, the requirement may be somewhat greater in the latter 

 case, since no glucose can be used. Even the carbohydrate formed from 

 the amino acids fails to be oxidized in severe diabetes, and this loss in cal- 

 ories must be compensated by increased fat oxidation. Moreover, because 

 the ketonuria is frequently extremely severe in diabetes, additional energy 

 must be rendered available by the partial oxidation of more fat, to com- 

 pensate for the loss of energy occurring as the result of the loss of the poten- 

 tial calories arising from the excretion of the unoxidized ketone bodies. 

 However, the intensity of the ketonuria which occurs, particularly in 

 women during fasting uncomplicated by diabetes, should not be underesti- 

 mated. It may be extremely severe, and in the same range as that which 

 occurs in diabetic acidosis. 408 



It is therefore understandable that, under conditions of diabetic acidosis, 

 a high requirement for fat exists in the tissues. Thus, the serum lipids 

 have invariably been found to be high when a diabetic acidosis is pres- 

 en t 596,612,613 i n addition to the increased requirement caused by the 

 failure of carbohydrate to be utilized and also by the inefficient utilization 

 of the calories of the fat which is broken down, another phenomenon occurs 

 which tends to exaggerate the increase in blood lipid. This factor is the 

 hemoconcentration which is usually present. There is a considerable loss 

 of fluid from the blood, due to the glycosuria and ketonuria which are oc- 

 curring concomitantly, with the result that the substances remaining in the 



612 E. B. Man and J. P. Peters, /. Clin. Invest., 13, 237-261 (1934). 



613 E. Sorkin and M. Batuschanskaja, Z. ges. exptl. Med., 74, 138-147 (1930). 



