What is the reference interval for fasting serum glucose in an adult expressed in SI units (International System of Units)?

What is the reference interval for fasting serum glucose in an adult expressed in SI units (International System of Units)?

• A. 1.7-3.3 mmol/L
• B. 3.3-5.6 mmol/L
• C. 4.1-5.5 mmol/L
• D. 6.7-8.3 mmol/L

Answer: (C)

The main idea here is the normal range used for fasting glucose measured in SI units. In healthy adults, fasting plasma glucose after an overnight or 8–12-hour fast is typically about 4.0 to 5.5 mmol/L. This interval reflects standard population data and common lab practices, and many laboratories adopt a lower bound around 4.1 mmol/L for practical use. In non-SI units, that corresponds to roughly 70–99 mg/dL. Values below about 4.0 mmol/L are generally considered hypoglycemic, while values above about 5.5 mmol/L can indicate impaired fasting glucose or diabetes risk, depending on context. The other options lie outside the typical fasting-normal range: some are clearly too low, and others are clearly elevated.

The main idea here is the normal range used for fasting glucose measured in SI units. In healthy adults, fasting plasma glucose after an overnight or 8–12-hour fast is typically about 4.0 to 5.5 mmol/L. This interval reflects standard population data and common lab practices, and many laboratories adopt a lower bound around 4.1 mmol/L for practical use. In non-SI units, that corresponds to roughly 70–99 mg/dL. Values below about 4.0 mmol/L are generally considered hypoglycemic, while values above about 5.5 mmol/L can indicate impaired fasting glucose or diabetes risk, depending on context. The other options lie outside the typical fasting-normal range: some are clearly too low, and others are clearly elevated.