Normal Values for Oral Glucose Tolerance Test (OGTT)
May 10, 2022
Source: Cainiu Health
Dr. Pan Yongyuan
Introduction
The oral glucose tolerance test (OGTT) typically involves five blood glucose measurements: fasting level is 6.9 mmol/L; at 30 minutes after glucose ingestion, the normal value is 10.5 mmol/L; at 60 minutes, it is 10.0 mmol/L; at 120 minutes, it is 7.8 mmol/L; and at 180 minutes, it is 6.9 mmol/L.
For some middle-aged and elderly individuals, regular hospital visits for an oral glucose tolerance test (OGTT) are recommended. This test is a diagnostic tool for diabetes. So, what are the normal reference values for the OGTT?
Normal Values for the Oral Glucose Tolerance Test
The OGTT typically involves five blood glucose measurements: fasting level ≤6.9 mmol/L; 30 minutes after glucose ingestion ≤10.5 mmol/L; 60 minutes ≤10.0 mmol/L; 120 minutes ≤7.8 mmol/L; and 180 minutes ≤6.9 mmol/L.
The glucose tolerance test—commonly referred to as the oral glucose tolerance test (OGTT)—is a laboratory method used to assess glucose metabolism. It is performed either intravenously (IVGTT) or orally (OGTT). IVGTT is generally reserved for clinical research evaluating glucose utilization or for special cases such as patients with malabsorption syndrome following gastrectomy. In contrast, OGTT is the most commonly used clinical diagnostic method.
Who should undergo an OGTT? First, individuals clinically suspected of having diabetes but whose diagnosis cannot be confirmed based on a single blood glucose measurement. Second, patients already diagnosed with diabetes who require comprehensive evaluation of their blood glucose peak response, insulin secretion capacity, and C-peptide levels. Third, individuals in whom diabetes must be differentiated from other conditions causing glycosuria—such as renal glycosuria or alimentary glycosuria. We hope this information is helpful to you.
