Research

Role of blood pressure in development of early retinopathy in adolescents with type 1 diabetes: prospective cohort study

BMJ 2008; 337 doi: 10.1136/bmj.a918 (Published 26 August 2008)
Cite this as: BMJ 2008;337:a918
  1. Patricia Herold Gallego, clinical research fellow in paediatric endocrinology1,
  2. Maria E Craig, paediatric endocrinologist123,
  3. Stephen Hing, ophthalmologist1,
  4. Kim C Donaghue, paediatric endocrinologist12
  1. 1Institute of Endocrinology and Diabetes, Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
  2. 2Discipline of Paediatrics and Child Health, University of Sydney, NSW 2006, Australia
  3. 3School of Women’s and Children’s Health, University of New South Wales, Sydney NSW 2052
  1. Correspondence to: K C Donaghue KimD{at}chw.edu.au
  • Accepted 9 June 2008

Abstract

Objective To examine the relation between blood pressure and the development of early retinopathy in adolescents with childhood onset type 1 diabetes.

Design Prospective cohort study.

Setting Diabetes Complications Assessment Service at the Children’s Hospital at Westmead, Sydney, Australia.

Participants 1869 patients with type 1 diabetes (54% female) screened for retinopathy with baseline median age 13.4 (interquartile range 12.0-15.2) years, duration 4.9 (3.1-7.0) years, and albumin excretion rate of 4.4 (3.1-6.8) μg/min plus a subgroup of 1093 patients retinopathy-free at baseline and followed for a median 4.1 (2.4-6.6) years.

Main outcome measures Early background retinopathy; blood pressure.

Results Overall, retinopathy developed in 673 (36%) participants at any time point. In the retinopathy-free group, higher systolic blood pressure (odds ratio 1.01, 95% confidence interval 1.003 to 1.02) and diastolic blood pressure (1.01, 1.002 to 1.03) were predictors of retinopathy, after adjustment for albumin excretion rate (1.27, 1.13 to 1.42), haemoglobin A1c (1.08, 1.02 to 1.15), duration of diabetes (1.16, 1.13 to 1.19), age (1.13, 1.08 to 1.17), and height (0.98, 0.97 to 0.99). In a subgroup of 1025 patients with albumin excretion rate below 7.5 μg/min, the cumulative risk of retinopathy at 10 years’ duration of diabetes was higher for those with systolic blood pressure on or above the 90th centile compared with those below the 90th centile (58% v 35%, P=0.03). The risk was also higher for patients with diastolic blood pressure on or above the 90th centile compared with those below the 90th centile (57% v 35%, P=0.005).

Conclusions Both systolic and diastolic blood pressure are predictors of retinopathy and increase the probability of early retinopathy independently of incipient nephropathy in young patients with type 1 diabetes.

Footnotes

  • Contributors: PHG was involved in statistical analysis, data interpretation, and drafting of the manuscript. MEC was involved in data collection, statistical analysis, data interpretation, and revision of the manuscript. SH was involved in data collection, including retinal photography assessment. KCD was involved in the conception and design of the study, collection and interpretation of data, and writing and revision of the manuscript. KCD is the guarantor.

  • Competing interests: None declared.

  • Ethical approval: Ethics committee of Children’s Hospital at Westmead, Sydney.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Rapid responses

THIS WEEK'S POLL

Read related article

See previous polls

BMJ most popular