Oral glucose tolerance test in diabetes, the old method revisited

Abstract

The oral glucose tolerance test (OGTT) has been widely used both in clinics and in basic research for a long time. It is applied to diagnose impaired glucose tolerance and/or type 2 diabetes mellitus in individuals. Additionally, it has been employed in research to investigate glucose utilization and insulin sensitivity in animals. The main aim of each was quite different, and the details are also somewhat varied. However, the time or duration of the OGTT was the same, using the 2-h post-glucose load glycemia in both, following the suggestions of the American Diabetes Association. Recently, the use of 30-min or 1-h post-glucose load glycemia in clinical practice has been recommended by several studies. In this review article, we describe this new view and suggest perspectives for the OGTT. Additionally, quantification of the glucose curve in basic research is also discussed. Unlike in clinical practice, the incremental area under the curve is not suitable for use in the studies involving animals receiving repeated treatments or chronic treatment. We discuss the potential mechanisms in detail. Moreover, variations between bench and bedside in the application of the OGTT are introduced. Finally, the newly identified method for the OGTT must achieve a recommendation from the American Diabetes Association or another official unit soon. In conclusion, we summarize the recent reports regarding the OGTT and add some of our own perspectives, including machine learning and others.

Synthesis, Antioxidant, and Antidiabetic Activities of Ketone Derivatives of Succinimide

“…OGTT is commonly used in clinics and in research [ 33 ] for the diagnosis of type 2 diabetes mellitus and impaired glucose tolerance [ 34 ]. It has also been used for the investigation of glucose sensitivity and glucose utilization in animals in research.…”

Effects of probiotic supplementation on glucose metabolism in pregnant women without diabetes: a systematic review and meta-analysis

“…A possible explanation for this might be that probiotic supplementation may reduce blood glucose not by directly improving β-cell function. 44 The plasma glucose levels obtained during the OGTT were related to both insulin sensitivity and secretion, reflecting the function of β-cells. 45,46 Though the underlying mechanisms have not been fully elucidated, there were studies showing that probiotics could increase insulin sensitivity and reduce autoimmune responses by modulating intestinal microbiota, thus decreasing the inflammatory reactions and oxidative stress.…”

Chemical Constituents and Effect of Ethanol Leaf Extract of Hibiscus articulatus Hochst. ex A. Rich. (Malvaceae) on Glucose- and Streptozotocin-Induced Hyperglycaemia using Wistar Rats

“…Results obtained from OGTT revealed that, the blood glucose level was highest at 30 minutes, post glucose administration and declined gradually up till 120 minutes of acute phase of the OGTT. The ability of the Wistar rats to metabolize the administered glucose, leading to decline in its concentration after 30 minutes of administration suggest the extract does not cause glucose tolerance nor affects the sensitivity of glucose to liver and other peripheral tissues (Ernsberger and Koletsky, 2012; Kuo et al, 2021), hence this suggests that ELEHA may possess antihyperglycaemic activity.…”