The Renal Threshold for Dextrose in Man

By the renal threshold for dextrose is generally understood that concentration of sugar in the blood above which sugar appears in the urine. In man this phenomenon has long been of interest, especially in relation to diabetes. It has been frequently studied, but current opinion¹is not in agreement as to the concept comprised in the term threshold for dextrose. The view of a fixed, unalterable concentration of dextrose in the plasma above which dextrose uniformly appears in the urine seems to be untenable. It is certain that by the ordinary methods of measurement there are many factors which cause the concentration to vary and that it not only is different in various persons but is not characteristic for a single subject. It is the purpose of the investigation reported here to examine some of the factors which it seemed might be largely responsible for a possibly apparent inconstancy