Normal Range for Glucose Tolerance

Glucose tolerance testing is likely unfamiliar to many people, yet it is well known among numerous expectant mothers. This test is an essential component of prenatal screening and directly impacts the health of the baby. So, what are the normal reference ranges for glucose tolerance?

Normal Reference Ranges for Glucose Tolerance

Glucose tolerance typically refers to the oral glucose tolerance test (OGTT). In healthy individuals, the normal fasting plasma glucose level is 3.9–6.1 mmol/L, and the 2-hour postprandial glucose level should be less than 7.8 mmol/L. However, these thresholds may differ during pregnancy.

Fasting plasma glucose exceeding 6.1 mmol/L and/or 2-hour postprandial glucose exceeding 7.8 mmol/L—especially when accompanied by symptoms such as polyuria, polydipsia, and unexplained weight loss—typically indicate a diagnosis of diabetes mellitus. During pregnancy, however, the diagnostic criteria for OGTT differ: fasting glucose should be <5.1 mmol/L; 1-hour post-glucose load glucose should be <10.0 mmol/L; and 2-hour post-glucose load glucose should be <8.5 mmol/L. Values exceeding these thresholds suggest gestational diabetes mellitus (GDM).

For individuals identified with abnormal results on the oral glucose tolerance test, dietary modifications and appropriate physical activity are crucial. A light, low-calorie diet is recommended. Engaging in moderate physical activity after meals helps promote calorie expenditure. Participating in aerobic exercise three to four times per week supports fat metabolism, enhances overall fitness, and aids in glycemic control. We hope this information proves helpful. Wishing you good health and happiness!