Association between HbA1c and the development of cystic fibrosis‐related diabetes. Issue 10 (15th February 2019)

• Record Type: Journal Article
• Authors: Choudhury, M.; Taylor, P.; Morgan, P. H.; Duckers, J.; Lau, D.; George, L.; Ketchell, R. I.; Wong, F. S.
• Is Part Of: Diabetic medicine. Volume 36:Issue 10(2019)
• Page Start: 1251
• Page End: 1255
• Publication Date: 2019-02-15
• Subjects: Diabetes -- Periodicals; 616.462
• DOI: 10.1111/dme.13912
• Languages: English
• ISSNs: 0742-3071

Abstract

Abstract: Aims: To examine HbA1c as a predictor of risk for future development of cystic fibrosis‐related diabetes and to assess the association with the development of retinopathy in people with cystic fibrosis‐related diabetes. Methods: A 7‐year retrospective longitudinal study was conducted in 50 adults with cystic fibrosis, comparing oral glucose tolerance test results with HbA1c values in predicting the development of cystic fibrosis‐related diabetes. Retinal screening data were also compared with HbA1c measurements to assess microvascular outcome. Results: An HbA1c value ≥37 mmol/mol (5.5%; hazard ratio 3.49, CI 1.5–8.1) was significantly associated with the development of dysglycaemia, as defined by the oral glucose tolerance test over a 7‐year period. Severity of diabetic retinopathy was associated with a higher HbA1c and longer duration of cystic fibrosis‐related diabetes. Conclusion: There is a link between HbA1c level and the future development of dysglycaemia in cystic fibrosis based on oral glucose tolerance test, as well as microvascular outcomes. Although current guidance does not advocate the use of HbA1c as a diagnostic tool in cystic fibrosis‐related diabetes, it may be of clinical use in determining individuals at risk of future development of cystic fibrosis‐related diabetes. What's new?: HbA1c has low sensitivity in the diagnosis of cystic fibrosis‐related diabetes (CFRD), and the oral glucose tolerance test (OGTT) is the current preferred method of diagnosis. There is an association between HbA1c and microvascular damage in CFRD, but the extent of this is not fully established. HbA1c level > 37 mmol/mol (5.5%) is associated with the development of a positive OGTT. Higher HbA1c levels are associated with severe forms of retinopathy. An HbA1c level > 37 mmol/mol (5.5%) in an individual who does not have a formal diagnosis of CFRD would be an indication for closer scrutiny of their glycaemic control.