82 DIABETES MELLITUS 



by a more or less extensive resection, true diabetes may be produced. Our 

 investigations in man, however, only correspond with this in so far as extir- 

 pation of the pancreas and disease of the pancreas also cause diabetes in the 

 human subject. On the other hand, diseases of the pancreas have only in 

 rare instances been determined with certainty as the cause of diabetes; these 

 affections are pancreatic calculi, pancreatic cirrhosis, neoplasms and cysts. 



If we have disease in an organ which is very influential in sugar metabo- 

 lism, as, for instance, the nervous system or pancreas, this suffices to produce 

 diabetes, even without a previous predisposition; if, however, a predisposi- 

 tion exists, disease of one of the vital organs is not absolutely necessary. 

 Slight general disturbances are sufficient to bring about an insufficiency in 

 sugar metabolism. Thus the varying etiology of diabetes mellitus becomes 

 comprehensible, and we learn to recognize as causes not only the above men- 

 tioned organic diseases, but also many severe or mild general affections: 

 influenza, enteric fever, scarlatina, erysipelas, phlegmons, syphilis, and, 

 finally, the most manifold forms of trauma, surgical operations, psychical dis- 

 turbances, bodily or mental over-exertion, indigestion and excesses of all 

 kinds; all of these are occasionally of etiological significance in diabetes 

 mellitus. 



This conception of diabetes mellitus as an expression of an hereditary 

 weakness of metabolism makes clear at once what we can expect as regards 

 the cure of diabetes. 



One can speak of actual cure only in those cases in which the disease 

 appears as the result of an affection of one of the principal organs; if an 

 affection of the organs in question improves, then diabetes may actually be 

 "cured." That this occurs is certain (in man) in the case of diabetes as" the 

 result of brain injuries. 



If, however, as in most cases, the cause of diabetes must be referred to 

 hereditary predisposition, we must at once assume a skeptical attitude in 

 regard to the cure, all the more so if the predisposition is the only causal 

 factor. Where other causes are associated with this, e. g., cirrhosis of the liver, 

 infectious diseases, especially syphilis (we may remark in passing that syphi- 

 lis plays but a very slight role in the etiology of diabetes), arterio-sclerotic 

 circulatory disturbances, we have more reason to hope that, by treatment or 

 by cure of the causes simultaneously present, sugar metabolism may again 

 become sufficient, but the predisposition remains, and with it the danger that 

 any fresh damage may bring about a relapse. 



Many cases may be explained in this way; for example, an elderly person who may 

 have suffered many years ago with diabetes, is apparently cured; i. e., he returns to his 

 usual mode of livmg without paying much attention to his " cured " diabetes. The 

 urine IS free from sugar; he is then attacked with influenza, or undergoes some marked 

 psychical disturbance, and the glycosuria at once returns quite severely; or he has to 

 submit to an operation, and after the operation a coma ensues, coma diabeticum, the 

 urine containing many per cent, of sugar. 



We are justified in assuming (as we have) an hereditary predisposition 

 tor many cases of diabetes, apart from what has already been said, by the fact 

 of the heredity of the disease. In most cases of diabetes, heredity is a factor; 



