Glucose Tolerance Test - Sample Method

Sample Method

It is important to stress that the diagnosis criteria stated above by the World Health Organisation (WHO) is for venous samples only i.e. a blood sample taken from a vein in the arm. An increasingly popular method for measuring blood glucose is from a capillary or finger-prick sample. This is less invasive, more convenient for the patient and requires minimal training to conduct. Whilst fasting blood glucose have been shown to be similar in both capillary and venous samples, postprandial blood glucose levels (those measured after a meal) can vary. Therefore the diagnosis criteria issued by the WHO should only be used for venous blood samples. Given the increasing popularity of capillary testing the WHO has recommended that a conversion factor between the two sample types be calculated. To date no conversion factor has been issued by the WHO despite some medical professionals adopting their own.