What is the lower limit for postprandial venous plasma glucose in healthy young adults?

There is general agreement that the lower limit for postprandial venous plasma glucose is the same or higher than for a fasted sample. The finding of a postprandial fall in glucose would therefore have implications for assignment of the lower limit of the normal glucose range.

An antecubital venous sample was collected before and one hour after breakfast. Plasma was separated immediately after collection and glucose measured using the hexokinase method. Participants with dysglycaemia were excluded from subsequent analysis.

Glucose range (mmol/L) for the 96 participants was 4.4-6.0 fasting and 2.7-7.2 postprandially. There was no relationship between postprandial glucose and either gender or carbohydrate intake. About 24% of postprandial concentrations were <3.9  mmol/L.

If laboratories choose to define a random venous plasma glucose reference range, the lower limit should be below 3.9  mmol/L.