Age at onset and the risk of proliferative retinopathy in type 1 diabetes

  1. on behalf of the FinnDiane Study Group
  1. 1. Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum Helsinki, Finland
  2. 2. Division of Nephrology, Department of Medicine, Helsinki University Central Hospital, Finland
  3. 3. Department of Ophthalmology, Helsinki University Central Hospital, Finland
  4. 4. Diabetes Prevention Unit, Institute for Health and Welfare, Helsinki Finland
  5. 5. The Baker IDI Heart and Diabetes Institute, Melbourne, Australia

Abstract

Objective: Age at onset of type 1 diabetes influences the risk of microvascular complications. However, the long-term risk of proliferative retinopathy within the wide spectrum of age at onset of type 1 diabetes is less well known.

Research design and methods: A sample of 1117 consecutively recruited patients was drawn from the FinnDiane Study population (4800 patients). Type 1 diabetes was defined as age at onset ≤ 40 years, insulin treatment initiated within one year and C-peptide ≤ 0.3 nmol/l. Retinopathy status was graded based on ophthalmic records and/or fundus photographs. The risk of proliferative retinopathy was studied in age at onset groups 0-4, 5-14 and 15-40 years.

Results: The mean durations to proliferative retinopathy were 24.3 (22.7-25.9) years in 0-4 group, 20.1 (19.2-21.1) years in 5-14 group and 21.6 (19.8-23.3) years in 15-40 group (P<0.001). In a Cox-regression model, with HbA1c, blood pressure, sex and body mass index as covariates, the highest risk of proliferative retinopathy was observed in 5-14 group (HR 1.90 [95% CI 1.45-2.48], P<0.001). Diabetes onset 0-4 vs. 5-14 years had no difference in the long-term risk of proliferative retinopathy (P=0.2). When split into two groups, age at onset <15 years was associated with a higher long-term risk than age at onset ≥15 years (HR 1.82 [95% CI 1.40-2.36], P<0.001).

Conclusions: Age at onset significantly modifies the long-term risk of proliferative retinopathy. The highest risk is in age at onset group 5-14 whereas the lowest risk is in the age at onset group 15-40 years.

Footnotes

    • Received December 14, 2009.
    • Accepted February 15, 2010.

This Article

  1. Diabetes Care
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