Glomerular Filtration Rate and Renal Plasma Flow in Normal and Diabetic Man during Elevation of Blood Sugar Levels

Abstract

Glomerular filtration rate (GFR) is abnormally elevated in early juvenile diabetes. In 7 normal and 7 diabetic subjects oral administration of glucose sufficient to raise plasma glucose 76 and 123 per cent, respectively, did not influence GFR and renal plasma flow (RPF) significantly. In 4 normal subjects, whose plasma glucose was raised by intravenous administration to values between 203 and 325 mg/100 ml, GFR increased by 5.7 per cent. This small increase is probably readily explained by the expansion of plasma volume and the fall in the colloid osmotic pressure of plasma during the infusion. There was no consistent change in RPF during infusion. It is concluded that in diabetics the elevated blood sugar per se does not explain the high GFR found in these patients.

Key Words:

• Diabetes
• glomerular filtration rate
• glucose
• kidney function
• renal plasma flow