Glycemic variability: Clinical implications

Abstract

Glycemic control and its benefits in preventing microvascular diabetic complications are convincingly proved by various prospective trials. Diabetes control and complications trial (DCCT) had reported variable glycated hemoglobin (HbA1C) as a cause of increased microvascular complications in conventional glycemic control group versus intensive one. However, in spite of several indirect evidences, its link with cardiovascular events or macrovascular complications is still not proved. Glycemic variability (GV) is one more tool to explain relation between hyperglycemia and increased cardiovascular risk in diabetic patients. In fact GV along with fasting blood sugar, postprandial blood sugar, HbA1C, and quality of life has been proposed to form glycemic pentad, which needs to be considered in diabetes management. Postprandial spikes in blood glucose as well as hypoglycemic events, both are blamed for increased cardiovascular events in Type 2 diabetics. GV includes both these events and hence minimizing GV can prevent future cardiovascular events. Modern diabetes management modalities including improved sulfonylureas, glucagon like peptide-1 (GLP-1)-based therapy, newer basal insulins, and modern insulin pumps address the issue of GV effectively. This article highlights mechanism, clinical implications, and measures to control GV in clinical practice.

Keywords: Diabetes mellitus; glycemic variability; incretins; oxidative stress.

Figure 1

Pathophysiological mechanism of hyperglycemia induced cellular damage mediated by oxidative stress. ROS- Reactive oxygen species, PARP- Poly adenosyl ribose phosphate, GAPDH- Glyceraldehyde 3-phosphate dehydrogenase, PKC-Protein kinase C, NF and #954; B-Nuclear factor kappa B, AGE-Advanced glycation end products, RAGE-Receptor for advanced glycation end products, PW-Pathway (Adapted from Giacco F et al., Circ Res. 2010; 107: 1058-70)