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A1C variability and the risk of microvascular complications in type 1 diabetes: data from the Diabetes Control and Complications Trial.

Kilpatrick ES, Rigby AS, Atkin SL - Diabetes Care (2008)

Bottom Line: Debate remains as to whether short- or long-term glycemic instability confers a risk of microvascular complications in addition to that predicted by mean glycemia alone.This study has shown that variability in A1C adds to the mean value in predicting microvascular complications in type 1 diabetes.Thus, in contrast to analyses of DCCT data investigating the effect of short-term glucose instability on complication risk, longer-term fluctuations in glycemia seem to contribute to the development of retinopathy and nephropathy in type 1 diabetes.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Biochemistry, Hull Royal Infirmary, Hull, UK. eric.kilpatrick@hey.nhs.uk

ABSTRACT

Objective: Debate remains as to whether short- or long-term glycemic instability confers a risk of microvascular complications in addition to that predicted by mean glycemia alone. In this study, we analyzed data from the Diabetes Control and Complications Trial (DCCT) to assess the effect of A1C variability on the risk of retinopathy and nephropathy in patients with type 1 diabetes.

Research design and methods: A1C was collected quarterly during the DCCT in 1,441 individuals. The mean A1C and the SD of A1C variability after stabilization of glycemia (from 6 months onwards) were compared with the risk of retinopathy and nephropathy with adjustments for age, sex, disease duration, treatment group, and baseline A1C.

Results: Multivariate Cox regression showed that the variability in A1C added to mean A1C in predicting the risk of development or progression of both retinopathy (hazard ratio 2.26 for every 1% increase in A1C SD [95% CI 1.63-3.14], P < 0.0001) and nephropathy (1.80 [1.37-2.42], P < 0.0001), with the relationship a feature in conventionally treated patients in particular.

Conclusions: This study has shown that variability in A1C adds to the mean value in predicting microvascular complications in type 1 diabetes. Thus, in contrast to analyses of DCCT data investigating the effect of short-term glucose instability on complication risk, longer-term fluctuations in glycemia seem to contribute to the development of retinopathy and nephropathy in type 1 diabetes.

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Related in: MedlinePlus

Relative risk of retinopathy progression over the range of patients within the 0–97.5th centile of mean A1C after adjusting for A1C SD, using the 2.5th centile as a reference (A) and for A1C SD after adjustment for mean A1C (B).
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f1: Relative risk of retinopathy progression over the range of patients within the 0–97.5th centile of mean A1C after adjusting for A1C SD, using the 2.5th centile as a reference (A) and for A1C SD after adjustment for mean A1C (B).

Mentions: Figure 1A shows the relative risk of retinopathy progression using both treatment groups combined in model 2 (Table 1) when applied to DCCT patients in the range of 0–97.5th centile of mean A1C after adjustment for A1C SD, using the 2.5th centile as a reference. Figure 1B shows the same patients over the same range of A1C SD after adjustment for mean A1C.


A1C variability and the risk of microvascular complications in type 1 diabetes: data from the Diabetes Control and Complications Trial.

Kilpatrick ES, Rigby AS, Atkin SL - Diabetes Care (2008)

Relative risk of retinopathy progression over the range of patients within the 0–97.5th centile of mean A1C after adjusting for A1C SD, using the 2.5th centile as a reference (A) and for A1C SD after adjustment for mean A1C (B).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2571045&req=5

f1: Relative risk of retinopathy progression over the range of patients within the 0–97.5th centile of mean A1C after adjusting for A1C SD, using the 2.5th centile as a reference (A) and for A1C SD after adjustment for mean A1C (B).
Mentions: Figure 1A shows the relative risk of retinopathy progression using both treatment groups combined in model 2 (Table 1) when applied to DCCT patients in the range of 0–97.5th centile of mean A1C after adjustment for A1C SD, using the 2.5th centile as a reference. Figure 1B shows the same patients over the same range of A1C SD after adjustment for mean A1C.

Bottom Line: Debate remains as to whether short- or long-term glycemic instability confers a risk of microvascular complications in addition to that predicted by mean glycemia alone.This study has shown that variability in A1C adds to the mean value in predicting microvascular complications in type 1 diabetes.Thus, in contrast to analyses of DCCT data investigating the effect of short-term glucose instability on complication risk, longer-term fluctuations in glycemia seem to contribute to the development of retinopathy and nephropathy in type 1 diabetes.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Biochemistry, Hull Royal Infirmary, Hull, UK. eric.kilpatrick@hey.nhs.uk

ABSTRACT

Objective: Debate remains as to whether short- or long-term glycemic instability confers a risk of microvascular complications in addition to that predicted by mean glycemia alone. In this study, we analyzed data from the Diabetes Control and Complications Trial (DCCT) to assess the effect of A1C variability on the risk of retinopathy and nephropathy in patients with type 1 diabetes.

Research design and methods: A1C was collected quarterly during the DCCT in 1,441 individuals. The mean A1C and the SD of A1C variability after stabilization of glycemia (from 6 months onwards) were compared with the risk of retinopathy and nephropathy with adjustments for age, sex, disease duration, treatment group, and baseline A1C.

Results: Multivariate Cox regression showed that the variability in A1C added to mean A1C in predicting the risk of development or progression of both retinopathy (hazard ratio 2.26 for every 1% increase in A1C SD [95% CI 1.63-3.14], P < 0.0001) and nephropathy (1.80 [1.37-2.42], P < 0.0001), with the relationship a feature in conventionally treated patients in particular.

Conclusions: This study has shown that variability in A1C adds to the mean value in predicting microvascular complications in type 1 diabetes. Thus, in contrast to analyses of DCCT data investigating the effect of short-term glucose instability on complication risk, longer-term fluctuations in glycemia seem to contribute to the development of retinopathy and nephropathy in type 1 diabetes.

Show MeSH
Related in: MedlinePlus