Are all glucose solutions used for oGTT equal?

AIMS: Oral glucose tolerance tests (oGTT) are widely used for the diagnosis of diabetes. It is well known that the reproducibility of oGTT is poor and that a number of factors have an impact on the outcome of this diagnostic test. It appears as if one aspect, the oral glucose solution (OGS) used has not achieved much attention. Very little is published about this, despite the fact that apparently most often not a pure and freshly prepared glucose solution is used but a ready-to-use solution prepared by a (pharmaceutical) company.

METHODS: A literature search was performed to find respective publications.

RESULTS: It appears as if no or only a small number of not adequately designed clinical-experimental studies have been performed comparing different OGS head-to-head.

CONCLUSIONS: The composition of such OGS, including the excipients added to improve taste and smell, can have an impact on blood glucose increase after drinking the given OGS. Such factors can also have an impact on endogenous insulin secretion. If significant differences in the blood glucose excursions exist depending on which OGS is used, this calls for the use of a standardized OGS in oGTT to have a comparable outcome everywhere.