The Glucose Tolerance Test, But Not Hba(1c), Remains The Gold Standard In Identifying Unrecognized Diabetes Mellitus And Impaired Glucose Tolerance In Hypertensive Subjects.
Cardiac Research Unit, Cardiology Department, Central Middlesex Hospital, London, United Kingdom. [email protected] The objective of this study was to compare the value of the oral glucose tolerance test (GTT), glycated hemoglobin concentration (HbA(1c)), and fasting plasma glucose (FPG) for identifying unrecognized diabetes mellitus (DM) and impaired glucose tolerance (IGT) in hypertensive subjects. One hundred forty-four consecutive subjects who were not known to have DM and who were attending the Hypertension Clinic underwent 24-hour ambulatory blood pressure (BP) monitoring. A GTT and an HbA(1c) measurement were also carried out. Abnormal results from GTT were found in 94 patients (65%). Results from FPG were not different between those with DM and IGT but were significantly higher than in the euglycemic subjects. The FPG was between 110-125 mg/dL (6.1-6.9 mmol/L) in 31% (n = 20) of patients with IGT and in 53% (n = 16) of those with DM. With use of the previously published criteria to diagnose DM of FPG > or = 103 mg/dL (5.7 mmol/L) and HbA(1c) > or = 5.9%, 33% of our diabetic subjects and 75% of those with IGT would have been misclassified as euglycemic. The previou Continue reading >>