HbA1c cutpoint for diagnosing Type 2 diabetes in Asian Indians determined
MedWire News: A glycated hemoglobin (HbA1c) cutpoint of 6.1% can be used as a screening test for Type 2 diabetes in Asian Indians, say researchers.
HbA1c of 6.5% or more has recently been accepted as a diagnostic test for Type 2 diabetes by the American Diabetes Association (ADA), but its validity as a diagnostic in Asian Indians – a high risk group – has not been established.
To address this, Anil Bhansali (Postgraduate Institute of Medical Education and Research, Chandigarh, India) and colleagues carried out a community based randomized cross-sectional study in Chandigarh of 1972 individuals aged 20 years or older.
The participants underwent an oral glucose tolerance test and their HbA1c was measured between April 2008 and August 2009.
Using the World Health Organization and non-HbA1c ADA criteria for diabetes (fasting plasma glucose of 126 mg/dl or more, or 2 hour plasma glucose of 200 mg/dl or greater), the team found that 6.7% of participants had newly detected diabetes, 9.7% had known diabetes, 16.6% had prediabetes, and 69.4% were normoglycemic. They estimated that 38% of people would be underdiagnosed using these criteria.
Bhansali and co-workers found that in this group of Asian Indians, an HbA1c level of 6.1% or more had an optimum sensitivity and specificity for diagnosing Type 2 diabetes of 81% and 81%.
The corresponding values for an HbA1c of at least 6.5% or 7.0% were 65% and 88% and 42% and 92%, respectively.
“The present study shows that an HbA1c level of 6.1% has optimal sensitivity and specificity to be considered as a screening test,” conclude the authors.
They add: “An HbA1c level of 6.5% has reasonably good specificity for diagnosis of diabetes and is in complete concordance with ADA recommendations.”
The results of this study are published in the Journal of Clinical Endocrinology and Metabolism.
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By Helen Albert