A1C Variability as an Independent Risk Factor for Microalbuminuria in Young People With Type 1 Diabetes
- M. Loredana Marcovecchio, MD1,2,
- R. Neil Dalton, PHD3,
- Francesco Chiarelli, MD2 and
- David B. Dunger, MD1,4
- 1Department of Paediatrics, University of Cambridge, Addenbrooke’s Hospital, Cambridge, U.K.
- 2Department of Paediatrics, University of Chieti, Chieti, Italy
- 3WellChild Laboratory, King's College London, Evelina Children's Hospital, London, U.K.
- 4Institute of Metabolic Science, University of Cambridge, Cambridge, U.K.
- Corresponding author: David B. Dunger, .
OBJECTIVE To assess the potential association between A1C variability (SD) and microalbuminuria in young people with type 1 diabetes.
RESEARCH DESIGN AND METHODS Serially collected samples for A1C measurement were available for 1,232 subjects with childhood-onset type 1 diabetes recruited to the Oxford Regional Prospective Study and the Nephropathy Family Study.
RESULTS The median (range) number of A1C assessments was 4 (2–16). Mean (SD) intrapersonal A1C was 9.5 (0.91). Mean A1C values and adjusted A1C-SD were higher in subjects with microalbuminuria (n = 227) than in those with normoalbuminuria (10.3 vs. 9.4%; 1.12 vs. 0.86%, P < 0.001). In a Cox regression model, SD for A1C was independently associated with microalbuminuria (Exp 131 [95% CI 1.01–1.35]).
CONCLUSIONS In the current study, A1C variability was an independent variable that added to the effect of A1C on the risk for microalbuminuria in youth with type 1 diabetes, a population highly vulnerable to vascular complications.
- Received October 26, 2010.
- Accepted January 23, 2011.
- © 2011 by the American Diabetes Association.
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