New research suggests relying solely on HbA1c significantly underestimates the prevalence of diabetes.
The study included 9,000 adults from the US 2005-2014 National Health and Nutrition Examination Survey, without a diabetes diagnosis. Participants underwent HbA1c testing and an oral glucose tolerance test (OGTT).
The data showed that the distribution of glucose tolerance states defined by HbA1c and OGTT differed significantly (P<.000001 in reference to ogtt the sensitivity of hba1c for diagnosis diabetes was per cent with a specificity cent. based on misclassified cases defined by ogtt.>
The sensitivity of HbA1c for the diagnosis of normal glucose tolerance (NGT) was 84.91 per cent, with a specificity of 43.53 per cent. HbA1c misclassified 15.09 per cent of NGT defined by OGTT.
The authors said the results indicate that the prevalence of diabetes mellitus defined solely by HbA1c is 'highly unreliable' with a significant tendency for underestimation. They concluded that HbA1c “should not be solely used in determination of prevalence of states of glucose tolerance.”
The research was presented at ENDO 2019, the Endocrine Society's annual meeting in New Orleans, Louisiana in the US at the weekend.