Figure 1. Relationship between HbA_1C and fasting plasma glucose.

Fasting plasma glucose values of STZ-induced diabetic rats were often found within the range of those of age-matched controls (indicated by the dotted lines), while diabetic HbA_1C values were always elevated. As this figure demonstrates, STZ-induced diabetes did not result in fasting hyperglycaemia in approximately 50 % of the animals, even in cases of prolonged diabetes. For this reason, HbA_1C was taken as a more reliable indicator of the presence of diabetes.