Maximum Tubular Reabsorption Capacity for Glucose and Renal Hemodynamics during Rapid Hypertonic Glucose Infusion in Normal and Diabetic Subjects

It is demonstrated that the maximum tubular reabsorption capacity for glucose (Tmo) is significantly increased in young patients with diabetes of short duration. (Mean value for diabetics: 419±50 mg/min (n = 10); mean value for normals: 352±64 mg/min (n = 9). GFR is also significantly increased in diabetics. For the whole material there was a clear positive correlation between GFR and Tmc. In the normal subjects GFR was constant during the high glucose level, whereas RPF increased. In the diabetics, RPF was constant but GFR decreased consistently about 9 per cent. In both diabetics and normals there was a decrease in urinary potassium excretion and an increase in urinary sodium excretion during glucose infusion.