D-Ribose as a Contributor to Glycated Haemoglobin

Glycated haemoglobin (HbA1c) is the most important marker of hyperglycaemia in diabetes mellitus. We show that D-ribose reacts with haemoglobin, thus yielding HbA1c. Using mass spectrometry, we detected glycation of haemoglobin with D-ribose produces 10 carboxylmethyllysines (CMLs). The first-order rate constant of fructosamine formation for D-ribose was approximately 60 times higher than that for D-glucose at the initial stage. Zucker Diabetic Fatty (ZDF) rat, a common model for type 2 diabetes mellitus (T2DM), had high levels of D-ribose and HbA1c, accompanied by a decrease of transketolase (TK) in the liver. The administration of benfotiamine, an activator of TK, significantly decreased D-ribose followed by a decline in HbA1c. In clinical investigation, T2DM patients with high HbA1c had a high level of urine D-ribose, though the level of their urine D-glucose was low. That is, D-ribose contributes to HbA1c, which prompts future studies to further explore whether D-ribose plays a role in the pathophysiological mechanism of T2DM. (C) 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.