Levels are influenced by many factors including previous carbohydrate diet, drugs, gastric emptying time and gastrointestinal surgery, as well as circulating insulin levels.
The following criteria for adults and children are based on recommendation made by the World Health Organisation and have been adopted by Diabetes UK.
|
|
Glucose concentration in mmol/L
|
|
Venous plasma
|
Capillary plasma
|
|
Diabetes mellitus
|
|
Fasting value
|
≥ 7.0
|
≥ 6.1
|
|
2h after glucose load
|
≥11.1
|
≥ 11.1
|
|
Impaired Glucose
Tolerance
|
|
Fasting Value
|
< 7.0
|
< 6.1
|
|
2h after glucose load
|
≥ 7.8 & <11.1
|
≥ 7.8
|
|
Impaired Fasting
Glycaemia
|
|
FastingValue
|
≥ 6.1 & <7.0
|
≥ 5.6 & <6.1
|
|
2h after glucose load
|
< 7.8
|
< 7.8
|
NOTE. If the fasting blood glucose concentration is in the diabetic range on more than one occasion, the oral GTT is superfluous.
The same criteria are used for pregnant patients but those fulfilling the criteria of impaired glucose tolerance and diabetes mellitus have gestational diabetes mellitus (GDM).
'Diabetic' levels of glucose are not infrequently found in stressed individuals.
