HbA 1c versus oral glucose tolerance test as a method to diagnose diabetes mellitus in vascular surgery patients

Table 3 The number of patients categorized as having normoglycaemia, intermediate hyperglycaemia and DM according to HbA_1c^aversus OGTT^bresults, and the distribution of patients within the different glycaemic categories

		HbA_1c^a
OGTT^b	Subjects	Normo-glycaemia (%)	Intermediate hyperglycaemia (%)	Diabetes mellitus (%)
Total	275	42 (15.3)	193 (70.2)	40 (14.6)
Normoglycaemia	152	27 (17.8)	120 (79.0)	5 (3.3)
Intermediate hyperglycaemia	90	13 (14.4)	57 (63.3)	20 (22.2)
Diabetes mellitus	33	2 (6.1)	16 (48.5)	15 (45.5)

^a HbA_1c ≥ 6.5% (48 mmol/mol) = diabetes mellitus, HbA_1c range of 5.7-6.4% (39-46 mmol/mol) = intermediate hyperglycaemia, and HbA_1c < 5.7% (39 mmol/mol) = normoglycaemia.
^b FPG + 2-h value. DM = FPG ≥ 7.0 mmol/l and/or two-h value ≥ 11.1 mmol/l. Intermediate hyperglycaemia = IGT defined as FPG < 7.0 mmol/L and a 2-h-value between 7.8 mmol/L and 11.1 mmol/L, and IFG defined as fasting glucose value between 6.1 mmol/L and 7.0 mmol/L with a normal 2-h-value. Normoglycaemia = FPG < 6.1 mmol/L and a 2-h-value < 7.8 mmol/L.