New research at Queen Mary University (QMU) has found that HbA1c, a common type 2 diabetes test may be inaccurate for thousands of South Asian people in the UK.
The research found a genetic variant in people of South Asian heritage that affects the results of the HbA1c test, leading to falsely lower results of blood sugar levels and delayed diagnosis.
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Dr Miriam Samuel, lead researcher at QMU’s Genes and Health Research Team said: ‘Many genetic variants linked to red blood cell conditions are ultra-rare amongst the Northern Europeans who have historically dominated genetic studies. We demonstrate one such variant that is carried by 7.6% of South Asians which could affect the accuracy of HbA1c and cause delays in diabetes diagnosis.’
The researchers looked at genetic and health data - from the Genes and Health study – of over 60,000 individuals of Bangladeshi or Pakistani ethnicity living in England, and the UK Biobank, involving 500,000 people of varied ethnicity living in the UK.
The study found the genetic variant identified in the South Asian population to be linked with changes in red blood cells.
Since the HbA1c tests give an average of blood sugar levels over 2-3 months by measuring how much sugar is stuck to red blood cells, it may lead to inaccuracies in test results for people carrying the variant.
In England, it is estimated that there are over 420,000 people from a South Asian background living with diabetes. With around 7.6% of South Asians carrying this variant, HbA1c test may be underestimating blood sugar levels in around 32,000 South Asian people with diabetes.
The findings suggest that other types of blood sugar tests, such as fasting glucose and oral glucose tolerance tests, might be needed in South Asian people who carry the variant.
Dr Samuel stressed the importance of studies that focus on ‘underserved populations’ in genetic research. These findings are ‘vital to understand the different pathways that may contribute to diabetes inequalities in these communities,’ she said.
Experts in the field have welcomed this new research, calling for further studies that consider ethnic diversity in genetic research.
Dr Elizabeth Robertson, Diabetes UK’s Director of Research said that the link between the HbA1c test results and ethnic diversity ‘should be urgently investigated further.’
‘It's incredibly important that healthcare professionals are armed with a precise way to evaluate average blood sugar levels over extended periods. Every individual at risk or with diabetes, regardless of their background, deserves equal access to effective diabetes care to live a healthy life and mitigate long-term diabetes complications,’ said Dr Robertson.