Reduced testing frequency for glycated hemoglobin, HbA1c, is associated with deteriorating diabetes control.

No Thumbnail Available
Authors
Waldron, Jenna
Ford, Clare
Issue Date
2014-10-01
Journal
Type
Multicentre Study
Peer-Reviewed Publication
Keywords
Blood glucose self-monitoring
Comparative Study
Diabetes mellitus
Disease progression
Glycated hemoglobin A
Physiologic monitoring
Patient compliance
Self-monitoring
Journal Title
Diabetes Care
Volume
37
Issue
10
Begin page
2731
End page
2737
Abstract
OBJECTIVE We previously showed that in patients with diabetes mellitus, glycated hemoglobin (HbA1c) monitoring outside international guidance on testing frequency is widespread. Here we examined the relationship between testing frequency and diabetes control to test the hypothesis that retest interval is linked to change in HbA1c level. RESEARCH DESIGN AND METHODS We examined repeat HbA1c tests (400,497 tests in 79,409 patients, 2008–2011) processed by three U.K. clinical laboratories. We examined the relationship between retest interval and 1) percentage change in HbA1c and 2) proportion of cases showing a significant HbA1c rise. The effect of demographics factors on these findings was also explored. RESULTS Our data showed that the optimal testing frequency required to maximize the downward trajectory in HbA1c was four times per year, particularly in those with an initial HbA1c of ≥7% (≥53 mmol/mol), supporting international guidance. Testing 3-monthly was associated with a 3.8% reduction in HbA1c compared with a 1.5% increase observed with annual testing; testing more frequently provided no additional benefit. Compared with annual monitoring, 3-monthly testing was associated with a halving of the proportion showing a significant rise in HbA1c (7–10 vs. 15–20%). CONCLUSIONS These findings provide, in a large, multicenter data set, objective evidence that testing outside guidance on HbA1c monitoring frequency is associated with a significant detrimental effect on diabetes control. To achieve the optimum downward trajectory in HbA1c, monitoring frequency should be quarterly, particularly in cases with suboptimal HbA1c. While this impact appears small, optimizing monitoring frequency across the diabetes population may have major implications for diabetes control and comorbidity risk.
Citation
Driskell OJ, Holland D, Waldron JL, Ford C, Scargill JJ, Heald A, Tran M, Hanna FW, Jones PW, Pemberton RJ, Fryer AA. Reduced testing frequency for glycated hemoglobin, HbA1c, is associated with deteriorating diabetes control. Diabetes Care. 2014 Oct;37(10):2731-7. doi: 10.2337/dc14-0297. PMID: 25249670.