American Journal of Epidemiology Advance Access originally published online on May 9, 2008
American Journal of Epidemiology 2008 168(1):80-88; doi:10.1093/aje/kwn100
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ORIGINAL CONTRIBUTIONS |
The Long-term Relation among Retinal Arteriolar Narrowing, Blood Pressure, and Incident Severe Hypertension
1 Centre for Vision Research, Department of Ophthalmology and the Westmead Millennium Institute, University of Sydney, Sydney, Australia
2 Retinal Vascular Imaging Centre, Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Melbourne, Australia
3 Singapore Eye Research Institute, National University of Singapore, Singapore
4 Menzies Centre for Health Policy, Faculty of Medicine, University of Sydney, Sydney, Australia
5 Centre for Clinical Epidemiology and Biostatistics, University of Newcastle, Newcastle, Australia
6 Department of Community, Occupational, and Family Medicine, National University of Singapore, Singapore
Correspondence to Dr. Jie Jin Wang, Centre for Vision Research, Department of Ophthalmology, University of Sydney, Westmead Hospital, Hawkesbury Road, Westmead, New South Wales, Australia 2145 (e-mail: jiejin_wang{at}wmi.usyd.edu.au).
Received for publication December 21, 2007. Accepted for publication March 21, 2008.
The authors assessed associations between retinal vascular signs and incident severe hypertension in an older population-based cohort. At baseline (1992–1994), 3,654 residents aged 49–97 years living in the Blue Mountains area west of Sydney, Australia, were examined; respectively, 2,335 (75.1%) and 1,952 (76%) survivors were reexamined 5 and 10 years later. Retinal arteriolar and venular calibers were measured, and average central retinal artery and central retinal vein equivalents for that eye were estimated. Severe hypertension was defined by previous diagnosis of hypertension plus antihypertensive medication use or by systolic blood pressure 
160 mmHg and/or diastolic blood pressure 100 mmHg at examinations. Of the 1,424 participants at risk, 618 developed severe hypertension over 10 years (cumulative incidence = 47.7%, 95% confidence interval: 44.9, 50.5). Participants who subsequently developed severe hypertension had significantly narrower mean central retinal artery equivalents than those who did not (187.0 vs. 191.9 µm, p < 0.0001). After adjusting for age, sex, body mass index, smoking, mean arterial blood pressure, and plasma glucose and triglyceride levels, baseline narrowing central retinal artery equivalent was associated with increased risk of severe hypertension (per standard deviation reduction, odds ratio = 1.1, 95% confidence interval: 1.1, 1.2; narrowest vs. widest quintile, odds ratio = 1.6, 95% confidence interval: 1.2, 2.1). These findings support structural narrowing in small arteries and arterioles antecedent to clinical onset of severe hypertension.
arteries; arterioles; Australia; cohort studies; hypertension; incidence; retinal vessels
Abbreviations: CRAE, central retinal artery equivalent; CRVE, central retinal vein equivalent; DBP, diastolic blood pressure; SBP, systolic blood pressure