13C-glucose breath tests: a non-invasive method for detecting early clinical manifestations of exogenous glucose metabolism in type 2 diabetic patients.

The [1-13C]glucose breath test, which has been used to evaluate glucose metabolism, is suitable for patients with late-stage diabetes, whereas the [2-13C]glucose breath test is ideal in the early stages. Although the [3-13C]glucose breath test is theoretically useful for evaluating the uptake of glucose and the anaerobic glycolysis system, it can be used in practice to distinguish reduced uptake from impaired oxidation of glucose in combination with the other two tests.