Glycemic Variability: How to Measure and Its Clinical Implication for Type 2 Diabetes

Am J Med Sci. 2018 Dec;356(6):518-527. doi: 10.1016/j.amjms.2018.09.010. Epub 2018 Oct 2.


Glycated hemoglobin A1c (A1C) levels have traditionally been the gold standard for assessing glycemic control and treatment efficacy in patients with type 2 diabetes. However, A1C does not take into account fluctuations in blood glucose levels known as glycemic variability (GV). In recent years, GV has become increasingly clinically relevant, because of a better understanding of the need to reach target A1C while avoiding hypoglycemia. GV relates to both hyperglycemia and hypoglycemia, and has been associated with poorer quality of life. Diabetes treatments targeting multiple pathophysiological mechanisms are most beneficial in controlling A1C and reducing GV. In clinical trials, a number of metrics are used to measure GV, many of which are not well understood in the clinical practice. Until a gold standard metric for GV is established, the variety of measurements available may confound the choice of an optimal treatment for an individual patient.

Keywords: Glycated hemoglobin A(1c); Glycemic control; Glycemic variability; Type 2 diabetes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Blood Glucose / analysis*
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Glycated Hemoglobin A / metabolism*
  • Humans
  • Hyperglycemia / drug therapy*
  • Hypoglycemia / drug therapy*
  • Treatment Outcome


  • Blood Glucose
  • Glycated Hemoglobin A