Reproducibility of impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) classification: a systematic review

BACKGROUND: The classifications of impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) represent glucose levels above normal, but below the decision threshold for diabetes. We sought to determine what the reproducibility of these classifications was when repeat tests were performed by conducting a systematic review of the literature. METHODS: All primary studies published in English of any study design were included. Studies …