GFR of a diabetic person is 90 ml/min. Blood glucose is 200 mg/dl. Calculate urinary glucose excretion rate if the Tm for glucose is 150 mg/min

Amount of filtered glucose = Plasma concentration of glucose X GFR = 90 ml/min X 200 mg /dl = 180 mg/min Rate of excretion of Glucose = Amount filtered - Tubular maximum Rate of excretion of Glucose = 180 mg/min -150 mg/min = 30 mg/min Ref : Ganong 25th ed/page 681