Open Access<p>The Oral Glucose Tolerance Test: 100 Years Later</p>
Author(s) -
Ram Jagannathan,
João Sérgio Neves,
Brenda Dorcely,
Stephanie T. Chung,
Kosuke Tamura,
Mary K. Rhee,
Michael Bergman
Publication year - 2020
Publication title -
diabetes, metabolic syndrome and obesity
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 0.853
H-Index - 43
ISSN - 1178-7007
DOI - 10.2147/dmso.s246062
Subject(s) - prediabetes , glycated hemoglobin , medicine , gestational diabetes , glucose tolerance test , diabetes mellitus , endocrinology , plasma glucose , type 2 diabetes , incidence (geometry) , impaired glucose tolerance , insulin resistance , pregnancy , gestation , biology , mathematics , geometry , genetics
For over 100 years, the oral glucose tolerance test (OGTT) has been the cornerstone for detecting prediabetes and type 2 diabetes (T2DM). In recent decades, controversies have arisen identifying internationally acceptable cut points using fasting plasma glucose (FPG), 2-h post-load glucose (2-h PG), and/or HbA1c for defining intermediate hyperglycemia (prediabetes). Despite this, there has been a steadfast global consensus of the 2-h PG for defining dysglycemic states during the OGTT. This article reviews the history of the OGTT and recent advances in its application, including the glucose challenge test and mathematical modeling for determining the shape of the glucose curve. Pitfalls of the FPG, 2-h PG during the OGTT, and HbA1c are considered as well. Finally, the associations between the 30-minute and 1-hour plasma glucose (1-h PG) levels derived from the OGTT and incidence of diabetes and its complications will be reviewed. The considerable evidence base supports modifying current screening and diagnostic recommendations with the use of the 1-h PG. Measurement of the 1-h PG level could increase the likelihood of identifying high-risk individuals when the pancreatic ß-cell function is substantially more intact with the added practical advantage of potentially replacing the conventional 2-h OGTT making it more acceptable in the clinical setting.