Measurement of Circulating Glucose Concentrations: The Time Is Now for Consistency among Methods and Types of Samples

Diabetes mellitus was first described in the Egyptian papyrus of Ebers in 1552 BC by people who noted the attraction of insects to the “sweet urine” of those who produced abnormal amounts and later by tasters of urine who could fashion a diagnosis by recognizing the “sweet taste”. The name “diabetes”, initially used in the 1st century AD, comes from the Greek word meaning “to pass through”. “Mellitus”, a Latin word meaning “sweet as honey”, was added in the 18th century. The first chemical tests to measure sugar in urine were developed in the early 19th century. Early in the last century, whole-blood colorimetric analyses became available to clinicians, despite complexities in the preparation and analysis of samples. The term “blood glucose” remains a prominent feature to describe the state of glycemia in patients with diabetes, whether as a fasting value, during a glucose tolerance test, or in monitoring glucose values to determine the insulin dose. Measurements of glucose in venous whole blood, capillary whole blood, or plasma still define diabetes mellitus by WHO criteria (1), with the American Diabetes Association (ADA) referring only to concentrations in plasma (2).Modern applications of glucose assays practically diverge in the diagnosis vs monitoring of treatment(s) of diabetes. Thus, diagnosis is best made in a certified laboratory with the measurement of glucose in plasma after a fast of at least 8 h (3). The benefits of relating closely monitored glucose concentrations to treatment decisions have become feasible and practical with the availability of small devices capable of measuring with precision and accuracy glucose from …