Postprandial Hyperglycemia and Glycemic Variability

Abstract

The aim of this article is to evaluate the pros and cons of a specific impact of postprandial hyperglycemia and glycemic variability on the—mainly cardiovascular (CV)—complications of diabetes, above and beyond the average blood glucose (BG) as measured by HbA1c or fasting plasma glucose (FPG). The strongest arguments in favor of this hypothesis come from impressive pathophysiological studies, also in the human situation. Measures of oxidative stress and endothelial dysfunction seem to be especially closely related to glucose peaks and even more so to fluctuating high and low glucose concentrations and can be restored to normal by preventing those glucose peaks or wide glucose excursions. The epidemiological evidence, which is more or less confined to postprandial hyperglycemia and postglucose load glycemia, is also rather compelling in favor of the hypothesis, although certainly not fully conclusive as there are also a number of conflicting results. The strongest cons are seen in the missing evidence as derived from randomized prospective intervention studies targeting postprandial hyperglycemia longer term, i.e., over several years, and seeking to reduce hard CV end points. In fact, several such intervention studies in men have recently failed to produce the intended beneficial outcome results. As this evidence by intervention is, however, key for the ultimate approval of a treatment concept in patients with diabetes, the current net balance of attained evidence is not in favor of the hypothesis here under debate, i.e., that we should care about postprandial hyperglycemia and glycemic variability. The absence of a uniformly accepted standard of how to estimate these parameters adds a further challenge to this whole debate.

MANAGEMENT OF ENDOCRINE DISEASE: Beneficial effect of real-time continuous glucose monitoring system on glycemic control in type 1 diabetic patients: systematic review and meta-analysis of randomized trials

“…The results of our meta-analysis support the notion that the use of RT-CGM is associated with a significant lowering of HbA1c as well as glycemic variability. Both components -chronic sustained hyperglycemia and acute glycemic fluctuations -lead to diabetes complications through two main mechanismsexcessive protein glycation and activation of oxidative stress (22). Tight glycemic control is therefore of great importance in diabetes management.…”

Consensus Report: The Current Role of Self-Monitoring of Blood Glucose in Non-Insulin-Treated Type 2 Diabetes

“…72 There is no consensus on the optimal metric for GV. 73 Both postprandial SMBG values and CGM data provide information on this phenomenon. Future studies of SMBG and CGM in isolation, as well as combinations of these two diagnostic measures, will likely determine a useful definition for GV and examine its role in the development of diabetes complications.…”

Design of FLAT-SUGAR: Randomized Trial of Prandial Insulin Versus Prandial GLP-1 Receptor Agonist Together With Basal Insulin and Metformin for High-Risk Type 2 Diabetes

“…Possible mechanisms for such effects include systemic inflammation (8,9), oxidative stress (10), endothelial dysfunction (11,12), intimal-medial thickening (13), and cardiac ischemia or arrhythmias (14)(15)(16). Considerable literature linking various CVD risk markers with glycemic variability has been published (17,18).…”