The results of experiments performed solely to determine, as nearly as clinically possible, the normal renal threshold for dextrose are reported in this paper.
Most of the previous information on this subject has been gleaned incidentally during the study of dextrose tolerance curves. A great many of the patients studied were hospital patients. The various values reported led us to attempt to discover the renal threshold in normal persons. We believe that while there are small amounts of reducing substances in the urine most of the time, there is a definite threshold level at which large quantities of dextrose are excreted in the urine. This is shown in numerous cases by an abrupt appearance of heavy precipitate when a series of successive specimens of urine are tested with Benedict's solution while the blood sugar is rising after the ingestion of a large quantity of dextrose.
The normal renal threshold has