Glucose Tolerance Test (GTT), Two Hour Oral (WHO Protocol)

Glucose measured two hours after a standardized glucose load during an oral glucose tolerance test (OGTT). Interpreted against the ADA diagnostic criteria: below 140 mg/dL is within range, 140–199 is above the expected range, and 200 or higher meets the threshold for confirmatory testing.

Fasting Glucose measures blood sugar levels after an overnight fast (typically 8-12 hours). It reflects baseline glucose regulation. While standard guidelines define diabetes risk based on thresholds (e.g., prediabetes 100-125 mg/dL, diabetes ≥126 mg/dL), longevity experts emphasize maintaining levels in a tighter, lower optimal range (e.g., 70-90 mg/dL) for better metabolic health, reduced glycation, and potentially lower risk of age-related diseases. Continuous Glucose Monitoring (CGM) provides much richer data on glucose variability and post-meal responses.