Plasmaglukos

Plasmaglukos is the concentration of glucose in blood plasma, the liquid component of blood from which cells and clotting factors have been separated. It is a fundamental clinical parameter used to assess carbohydrate metabolism and to diagnose and monitor disorders of glucose regulation, such as diabetes mellitus, impaired glucose tolerance, hypoglycemia, and hyperglycemia. The term is used in various languages; in English, “plasma glucose” is the common formulation.

Measurement and handling: Plasma glucose is measured from a blood sample drawn into a tube containing an anticoagulant and a glycolysis inhibitor (for example fluoride-oxalate). To minimize glucose loss to glycolysis, samples are processed promptly or kept on ice, and plasma is obtained by centrifugation. Glucose concentration is determined by enzymatic methods, commonly glucose oxidase or hexokinase assays, in a clinical laboratory; point-of-care devices may use whole blood with conversion to plasma values. Plasma glucose differs slightly from serum glucose due to clotting factors, and can be influenced by sample handling and timing.

Interpretation and ranges: Fasting plasma glucose normally lies between about 3.9 and 5.5 mmol/L (70-99 mg/dL). A fasting level of 5.6 to 6.9 mmol/L is often considered impaired fasting glucose, while a fasting level of ≥7.0 mmol/L (126 mg/dL) on two occasions supports a diagnosis of diabetes in many guidelines. A 2-hour plasma glucose value after a 75 g oral glucose tolerance test of ≥11.1 mmol/L (200 mg/dL) indicates diabetes. Random plasma glucose ≥11.1 mmol/L with symptoms can also indicate diabetes. Values are interpreted in the context of clinical guidelines and patient history.

Clinical use: Plasma glucose testing is central to diagnosing diabetes, monitoring treatment, and guiding management alongside other measures such as HbA1c.