High rate of abnormal glucose tolerance in Brazilian individuals undergoing coronary angiography

Abstract

Introduction Undiagnosed hyperglycemia is common in high cardiovascular risk individuals, especially in those with coronary artery disease (CAD). There is no consensus about the optimal method for the screening of hyperglycemia in this population.Subjects and methods Five hundred and fourteen Brazilian individuals undergoing coronary angiography, without previously known diabetes mellitus (DM), had their glycemic status evaluated by both fasting plasma glucose (FPG) and HbA1c, being classified in normal (N), prediabetes (PD), and DM according to American Diabetes Association criteria. Concordance between both methods was assessed by Cohen’s κ. Accuracy of FPG and HbA1c to diagnose CAD was evaluated as proof-of-concept.Results Among individuals screened by FPG, 41.2% had PD and 6% had DM. Among those screened by HbA1c, 52.7% had PD and 12.7% had DM. Concordance for a positive screening of PD occurred in 125 individuals (κ = 0.084). Eighteen individuals had a concordant positive screening of DM (κ = 0.310). As a predictor of CAD, accuracy of FPG was 0.554 (p = 0.009) and of HbA1c 0.557 (p = 0.006).Conclusion a high frequency of hyperglycemia, between 47 and 65%, was found in individuals submitted to coronary angiography without previously known glucose disturbances, using FPG and HbA1c as screening methods respectively.HbA1c detected significantly more individuals with both PD and DM than FPG. Concordance between both methods is low. The question of which is the gold-standard method to diagnose hyperglycemia in this population is still open.

Keywords

• Cardiovascular disease
• hyperglycemia
• coronary angiography