Insulin's acute effects on glomerular filtration rate correlate with insulin sensitivity whereas insulin's acute effects on proximal tubular sodium reabsorption correlate with salt sensitivity in normal subjects

• Published in: Nephrology, dialysis, transplantation dialysis, transplantation, 1999-10, Vol.14 (10), p.2357-2363
• Main Authors: ter Maaten, Jan C., Bakker, Stephan J. L., Serné, Erik H., ter Wee, Pieter M., Donker, Ab J. M., Gans, Rijk O. B.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; blood pressure; insulin; insulin sensitivity; Investigative techniques of renal and urinary tract function; Investigative techniques, diagnostic techniques (general aspects); lithium; Medical sciences; salt sensitivity; sodium
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/14.10.2357

Background. Insulin induces sodium retention by increasing distal tubular sodium reabsorption. Opposite effects of insulin to offset insulin-induced sodium retention are supposedly increases in glomerular filtration rate (GFR) and decreases in proximal tubular sodium reabsorption. Defects in these opposing effects could link insulin resistance to blood-pressure elevation and salt sensitivity. Methods. We assessed the relationship between the effects of sequential physiological and supraphysiological insulin dosages (50 and 150 mU/kg/h) on renal sodium handling, and insulin sensitivity and salt sensitivity using the euglycaemic clamp technique and clearances of [131I]hippuran, [125I]iothalamate, sodium, and lithium in 20 normal subjects displaying a wide range of insulin sensitivity. Time-control experiments were performed in the same subjects. Salt sensitivity was determined using a diet method. Results. During the successive insulin infusions, GFR increased by 5.9% (P=0.003) and 10.9% (P