Potential clinical error arising from use of HbA1c in diabetes: effects of the Glycation Gap.

Potential clinical error arising from use of HbA1c in diabetes: effects of the Glycation Gap.
Endocr Rev. 2019 May 10;:
Authors: Nayak AU, Singh BM, Dunmore SJ
Abstract
The Glycation Gap (GGap) and the similar Hemoglobin Glycation Index (HGI) define consistent differences between glycated hemoglobin and actual glycemia derived from fructosamine or mean blood glucose respectively. Such a disparity may be found in a substantial proportion of people with diabetes, being > than 1 unit of glycated HbA1c% or 7.2 mmol/mol in almost 40% of estimations. In this review we define these indices, explain how they can be calculated and that they are not spurious, being consistent in individuals over time. We evaluate the evidence that GGap and HGI are associated with variation in risk of complications and mortality and demonstrate the potential for clinical error in the unquestioning use of HbA1c. We explore the underlying etiology of the variation of HbA1c from mean glucose in blood plasma including the potential role of enzymatic deglycation of hemoglobin by fructosamine-3-kinase. We conclude that measurement of GGap and HGI are important to diabetes clinicians and their patients in individualization of therapy and the avoidance of harm arising from consequent inappropriate assessment of glycemia and use of therapies.
PMID: 31074800 [PubMed - as supplied by publisher]

Source: Endocrine Reviews - May 12, 2019 Category: Endocrinology Tags: Endocr Rev Source Type: research