Effect of protein concentration on the formation of glycated albumin and fructosamine

Abstract

Abstract Considerable debate surrounds the question of whether fructosamine concentration should be corrected for serum protein concentration (see 1 for review). Staley (2) has argued against such correction, given that, theoretically, glucose concentration is the rate-limiting step in the glycation reaction; i.e., available lysine residues willalways be in excess of reactive open-chain (carbonyl) glucose molecules, which are only 0.001% of the total (3). However, because the open-chain and cyclic forms of glucose exist in freely exchangeable equilibrium, we conjectured that, as carbonyl glucoses were removed by glycation, more glucose molecules would rapidly isomerize to the open-chainform to maintain the equilibrium, if so, then protein concentration would also be an important factor in determining the glycation rate.