Body fluid kinetics is changed by a rise in plasma glucose

Abstract

Glucose is an osmotically active molecule and, therefore, rapid changes in plasma glucose might redistribute water volume between the body fluid compartments in a yet unknown way. To study this issue, population volume kinetic analysis was applied to repeated measurements of plasma glucose, blood hemoglobin, and urine output during and after 84 intravenous infusions of 2.5 % glucose with 70 mmol of sodium and in 9 control experiments using Ringer's solution. Forty-nine infusions were given to healthy volunteers, 11 to patients undergoing surgery, and 24 to patients with type 2 diabetes. The results showed that a rise in plasma glucose without marked glucosuria accelerated the distribution of fluid while the return of extravascular fluid to the plasma was strongly retarded. High plasma glucose also decreased the urine output, which was probably due to sodium retention. The summary effect was that fluid-induced plasma volume expansion subsided within 30 min after an infusion ended while extracellular fluid volume remained increased for several hours. Accumulation of fluid was most pronounced in the patients with type 2 diabetes and in the surgical patients. Plasma glucose, HOMA-IR, and Ouicki values did not correlate with any of the kinetic parameters. In conclusion, a rise in plasma glucose conserved infused fluid in the body and promoted peripheral accumulation. A specific effect of type 2 diabetes further decreased the urine flow.