264 ROLLIN T. WOODYATT 



Glycosuria 



Whereas the normal urine at all times contains reducing substances 

 and substances which are optically active, which yield crystalline com- 

 pounds with the hydrazins and respond to other tests as sugars do, these 

 substances are not all sugars nor are all the sugars glucose. The quantity 

 of fermentable reducing substance in normal urine averaged about 4 parts 

 in 10,000 (0.04 per cent) according to Lavesson. Bang and Bohamann- 

 son estimated the total reducing substance in the urine of normal adults 

 as between 0.21 and 0.24 per cent, of which about 18 per cent was fer- 

 mentable (0.038 to 0.043 per cent of fermentable reducing substances). 

 Benedict, Osterberg and Neuwirth found an excretion of fermentable re- 

 ducing substance ranging between 0.903 and 1.161 gm. in twenty-four 

 hours in the case of a normal adult on an ordinary mixed diet. During 

 a fast it approached zero, according to these writers, and on a diet low 

 in carbohydrate it averaged 0.75 gm., while with a high carbohydrate 

 diet it rose to 1.5 gm. 



The term glycosuria means the passage of glucose in the urine and it 

 would follow that glycosuria is a normal phenomenon. However, the 

 term was first used in connection with the abnormally increased glyco- 

 surias of diabetes and, as it appears in the medical literature without 

 qualification, it is commonly intended to mean an excretion of more than 

 the normal quantity of glucose. As it has been expressed by Naunyn(c) 

 "Wenn wir schlechthin von Glykosurie als einer krankhaften Erscheinung 

 sprechen so meinen wir freilich die iiber die norm gesteigerte Glykosurie; 

 wahrend auch in der\Norm der Urin (des Menschen) eine ganze geringe 

 Menge Zucker, und zwar Traubenzucker (Glykose) enthalte. Aber auch 

 die iiber die Norm gesteigerte Glykosurie kommt ohne Diabetes vor." 



What then constitutes a normal glycosuria and what is to be regarded 

 as abnormal ? A custom in the clinic is to test the native urine by means 

 of one of the well known qualitative sugar test solutions. A positive test is 

 then used as the criterion of an abnormal quantity of reducing substance, 

 a negative test of a normal quantity. But the positive or negative result 

 depends on the delicacy of the test as performed, on the concentration of 

 the reducing substance in the specimen and on the quantity of interfering 

 substances. In border-line cases the simple qualitative copper test is capa- 

 ble of giving false impressions. The error arising from method and varia- 

 tions of the urinary volume may indeed be obviated in a measure by bring- 

 ing the urine for 24 hours to a standard volume of 1, 2 or 3 c.c. per kg. of 

 body weight per hour of secretion and always performing the test in the 

 same way, but a truly quantitative method is to be preferred. Benedict 

 and Osterberg(6) (c), working with a new method for the quantitative esti- 



