Population-derived cut-off for HbA1c could enhance the identification of metabolic syndrome among non-diabetic population

BACKGROUND: Metabolic syndrome (MetS) is a multifactorial disorder and a predisposing factor for diabetes, heart diseases, and stroke. Glycated haemoglobin (HbA1c) has recently received considerable attention as a potential marker to identify subjects at risk of MetS. This study aimed at assessing the performance of fasting plasma glucose (FPG), the American Diabetes Association (ADA) HbA1c cut-off, and a population-derived HbA1c (pHbA1c) cut-off value as the glycaemic criterion for MetS in a non-diabetic population. METHODS: In this cross-sectional study, we recruited 728 non-diabetic Ghanaian adults. Venous blood sample was obtained and fasting plasma insulin and glucose, HbA1c, lipid profile, blood pressure and anthropometric measurements were performed for each respondent. RESULTS: The prevalence of MetS using the FPG, ADA HbA1c and pHbA1c criteria were 35.2%, 38.5% and 41.8%, respectively. The pHbA1c cut-off identified 6.6% and 3.3% more subjects with MetS when compared with FPG and the ADA HbA1c cut-offs, respectively while the ADA HbA1c cut-off identified 3.3% more subjects with MetS compared with the FPG criterion. The ADA HbA1c criterion showed a substantial agreement (ĸ = 0.79) with the FPG criterion while pHbA1c showed an almost perfect concordance (ĸ = 0.82) with the FPG criterion and an excellent sensitivity and specificity for identifying subjects with MetS in the study population. CONCLUSION: Screening of MetS by introduction of the ADA HbA1c criterion in addition to the traditional FPG criterion enhances the detection of more people with MetS. However, the use of population-derived HbA1c cut-off value could potentially identify even greater number of high risk subjects in that specific population.