HbA1c results, relative to fasting plasma glucose, vary widely across different Asian ethnic groups, finds a large study.
Malay and Indian people have HbA1c levels up to 2.6 mmol/mol higher than Chinese people at the same fasting plasma glucose levels.
Researchers in Singapore examined a sample of 3895 Chinese, Malay and Indian individuals without diabetes, adjusting results for age, gender, waist circumference, serum cholesterol, serum triglyceride and insulin resistance.
In those with a fasting plasma glucose level of 5.6 mmol/l, HbA1c levels were 1.1 mmol/mol higher in Indians and 0.9 mmol/mol higher in Malays, compared with Chinese. And the different was even greater at higher fasting plasma glucose concentrations – at a level of 7.0 mmol/l there was a difference of 2.1 mmol/mol between Indian and Chinese participants, and a difference of 2.6 mmol/mol between Malays and Chinese.
Study author Dr Eric Khoo assistant professor at the Department of Medicine, National University of Singapore said that knowledge and awareness of this magnitude of difference in HbA1c levels is important for clinicians:
‘If a single HbA1c cut-off is used to diagnose diabetes (and pre-diabetes) across these three ethnic groups, it will reclassify more Indians and Malays as having these conditions than Chinese, compared with fasting plasma glucose-based criteria.'
Diabetic Medicine 2012, online first 27 January