Endocrine Abstracts

Impaired glucoregulation is an important factor in the development of coronary heart disease. Numerous studies have reported a significant incidence of undiagnosed glucose intolerance in patients with coronary heart disease.

Aim: The aim of our study was to compare the utility of HbA1c versus oral glucose tolerance test (GTT) in detecting glucose tolerance abnormality in patients with coronary heart disease admitted for elective coronarography.

Participants and Methods: We have analyzed 100 subjects with no prior knowledge of glucose intolerance. Oral GTT with 75 g of glucose and HbA1c were performed prior to the coronarography. Based on the coronarography findings the subjects were divided in 4 groups: no significant stenosis (less than 50% stenosis), single vessel, two vessel or three vessel coronary artery disease (with stenosis ≥50%).

Results: Oral GTT showed that 23% subjects had normal glucose tolerance (NGT), 8% impaired fasting glucose, 39% glucose intolerance (IGT), while 30% were diagnosed with diabetes mellitus type 2 (DMT2). Based on HbA1c assessment, 24% subjects had NGT (HbA1c <5.7%), 55% prediabetes (HbA1c 5.7–6.4%) and 21% DMT2 (HbAlc ≥ 6.5%). The incidence of patients with IGT and DMT2 correlated to the severity of coronary heart disease (P<0.05). No significant difference in HbA1c levels was observed between the groups with different degree of coronary heart disease. HbA1c had lower specificity and sensitivity compared to OGTT (Yuden index 0.06–0.49).

Conclusion: In conclusion, OGTT is superior to HbA1c in glucose tolerance assessment and should be applied as a routine screening procedure in patients with coronary heart disease.

Keywords: OGTT, HbA1c, coronarography