Anemia, Author Interviews, Diabetes, Diabetologia / 18.05.2015
Iron Deficiency Anemia May Complicate Diagnosis of Diabetes
MedicalResearch.com Interview with:
Emma English PhD
Lecturer in Healthcare Science and Academic Lead for Clinical Biochemistry
University of Nottingham, School of Medicine
Royal Derby Hospital, UK
MedicalResearch: What is the background for this study? What are the main findings?
Dr. English: HbA1c is widely used for monitoring glycaemic control in people with diabetes as there is clear evidence that lowering HbA1c values leads to reductions in the rates of diabetes complications. Recently the World Health Organization and the American Diabetes Association have both advocated the use of HbA1c for the diagnosis of Type 2 diabetes at a value of ≥48 mmol/mol (6.5%). Whilst there are many advantages to the use of HbA1c as a diagnostic tool there are equally some significant limitations to its use. A widely cited confounder is anaemia, however to what extent and which types of anaemia affect HbA1c results was not clearly understood. When HbA1c was introduced as a diagnostic test in England we received many queries from healthcare professionals asking questions such as ‘at what level of anaemia should I not use HbA1c?’ and ‘should I routinely screen patients for anaemia when using HbA1c? And if so, what test should I use?’. In order to answer these questions we conducted a systematic review of the literature to determine what was known on this subject.
Our findings, presented in Diabetologia, suggest that iron deficiency and iron deficiency anaemia may lead to a spuriously elevated HbA1c level, thus may lead a false positive diagnosis of diabetes. However, non-iron deficiency anaemias can lead to an artificially lower HbA1c and may lead to a false negative result where a diagnosis of diabetes would be missed. There is no clear evidence to suggest at what levels anaemia can give rise to these effects on HbA1c value and also there does not appear to be a single ideal test for identifying patients where this could be an issue.
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