[Measurement of kidney concentrating ability in children with nonrenal glycosuria].

In non-renal (diabetic) glucosuria we did not find any statistically real relations between the concentration of glucose in the urine and cryoscopically measured osmolality in children with healthy kidneys. The close negative correlation of the conductance of the urine to the concentration of glucose is not only to be explained by changes of the viscosity, but is an expression of an increased re-absorption of sodium as a result of a compensatory hyperaldosteronism. In renal insufficiency the electrolytic conductibility of the urine is lower than the borderline area of the normal, even when under influence of the glucose excretion the osmolality of the urine is still to be found normal. Thus also on the conditions of a considerable glucosuria we can further judge the concentrating ability of the kidney in diabetes mellitus with the help of the measurement of the conductance of the urine.