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Estimation of blood glucose control in diabetes mellitus

David K McCulloch, MD
Section Editors
David M Nathan, MD
Joseph I Wolfsdorf, MB, BCh
Deputy Editor
Jean E Mulder, MD


The demonstration that the development of microvascular complications in patients with type 1 diabetes can be slowed by treating hyperglycemia has led to increased use of intensive insulin regimens to attain strict glycemic control (figure 1 and figure 2) [1-3]. The efficacy of these regimens requires an accurate method to estimate the degree to which this is achieved. It is helpful to first review some basic concepts before discussing the utility of measurements of glycated hemoglobin (A1C) and serum fructosamine to assess glycemic control.

There are three useful measurements for defining glycemic control:

The mean blood glucose concentration has often been measured in clinical trials as the mean of values obtained before breakfast, mid-morning, before lunch, mid-afternoon, before dinner, and before sleep each day. Clinically, this can be replaced with or supplemented by the more simple measurement of A1C. In some cases, however, there is a disparity between the A1C values and mean blood glucose values. (See 'Recommendations in type 1 diabetes' below.)

The degree to which blood glucose concentrations fluctuate within the same day can be formally measured as the mean amplitude of glycemic excursions [4].

The degree to which blood glucose concentrations fluctuate from day to day can be formally measured as the mean of daily differences [5].

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Literature review current through: Nov 2017. | This topic last updated: Jul 13, 2017.
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