A1C Variability as an Independent Risk Factor for Microalbuminuria in Young People With Type 1 Diabetes

  1. David B. Dunger, MD1,4
  1. 1Department of Paediatrics, University of Cambridge, Addenbrooke’s Hospital, Cambridge, U.K.
  2. 2Department of Paediatrics, University of Chieti, Chieti, Italy
  3. 3WellChild Laboratory, King's College London, Evelina Children's Hospital, London, U.K.
  4. 4Institute of Metabolic Science, University of Cambridge, Cambridge, U.K.
  1. Corresponding author: David B. Dunger, dbd25{at}cam.ac.uk.

Abstract

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.

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