Mismatch between HbA1c and fasting glucose in ethnic and gender groups

Abstract

Aims: Previous research has shown that a mismatch can occur between HbA1c and fasting glucose, which may be increased in certain ethnic groups. This study aimed to combine the most recent NHANES data to create a larger dataset than previous studies, to identify differences between ethnic groups, but also analysing age, BMI, and gender groups. Methods: Batches of NHANES data were combined using R software. This produced a larger dataset than in previous studies. The participants were divided into black and white ethnic groups (n=13,499). The HbA1c mismatch in each ethnic group was analysed, to observe differences between ethnic groups. This procedure was repeated for Gender (n=20,416), Age and BMI groups. This was also repeated for 3 retinopathy severity level groups. Results: This suggested that the mismatch between HbA1c and Fasting glucose was different between the ethnic groups and between the gender groups, but not between age groups or BMI groups. Between the 3 retinopathy severity level groups, it was found that both HbA1c and fasting glucose increased as retinopathy severity increases, but no difference was found in HbA1c mismatch. Conclusions: The glycaemic index gap or HbA1c mismatch varies between ethnic and gender groups, but not between BMI and age groups. It could be useful to develop customised HbA1c thresholds to use for diagnosing diabetes in certain ethnic and gender groups, to account for mismatch between these groups.