GENUINE DIABETES MELLITUS 527 



metabolic disturbances in order to discuss later the position of the pancreas 

 in the pathogenesis of diabetes mellitus. 



The Carbohydrate Metabolism. Among the symptoms of diabetes 

 mellitus, glycosuria is the most striking for physician and laity. Theoretically 

 and also more practically important, certainly, is hyperglycemia, for glycosuria 

 is only a result of this. There is in diabetes mellitus an excretion of sugar 

 without hyperglycemia, but not rarely does there occur hyperglycemia 

 without excretion of sugar. If the diabetes has existed for a long time, the 

 kidneys lose their finer sensitiveness for the heightening of the blood-sugar 

 contents, they gain in sugar-imperviousness (v. Noor den, Lief mann, and Stern}. 

 There is also in such cases no proportion between the degree of the hypergly- 

 cemia and the intensity of the glycosuria. Especially is this true for the dia- 

 betes of old age. The fact is also very important, as may be expected, that 

 the tolerance only rises when the sugar in the blood has been for a long time 

 normal, and that a series of symptoms, that we regard as the sequel of a long- 

 continuing hyperglycemia (furunculosis, impotence, diabetic gangrene, 

 rheumatoid pains, etc:) only vanish when the hyperglycemia is combated. 



For the assumption of diabetic disturbance of metabolism there is neces- 

 sary the demonstration that the sugar excreted in the urine is grape-sugar. 

 Further, there must be excluded a series of conditions that according to 

 experience are associated with a temporary excretion of sugar, or at least 

 appreciably reduce the tolerance for carbohydrates. Of such conditions I 

 mention acute febrile diseases, intoxication with carbon monoxide or mor- 

 phine, and asphyxic conditions, etc. 



It should further be considered that after copious ingestion of sugar, 

 sometimes slight amounts of sugar are found in the urine of even normal 

 human beings. The glycosurias in certain ductless diseases especially in 

 Basedow's disease and in acromegaly are considered in detail in the chapters 

 on the subject. We shall consider later the matter of nervous glycosurias 

 (in traumatic neurosis, hysteria, neurasthenia, and in certain nervous diseases, 

 such as tabes and [general] paralysis). 



I might here mention the laws that the excretion of sugar follows. In the 

 great majority of cases of diabetes we can observe a narrow relation between 

 intake of food and excretion of sugar. If we place such a diabetic on a diet 

 of a constant composition, the excretion of sugar sets in at a definite level and 

 maintains it for a long time. In cases that have not advanced entirely too far, 

 it is known that the tolerance may be influenced by a corresponding dietetic 

 regime. If the patient on account of the limitation of the sugar-forming 

 material becomes sugar-free, and if the amount of sugar in the blood remains 

 for a long time normal, a reparation occurs, so that later a diet without gly- 

 cosuria may be borne that formerly led to sugar-excretion. On the other 

 hand the tolerance is depressed when a high sugar-content of the blood has 

 existed for a long time. 



