Abstract
Abstract: :
Purpose: To assess longitudinal associations between retinal arteriolar diameter and past, current and future blood pressure (BP) in an older population. Methods: The Blue Mountains Eye Study examined 3654 (82.4%) Australian residents aged 49 years or older in 1992–4. Surviving participants (2335, 75.1%) were re–examined in 1997–9. BP was measured at baseline (past) and at the 5–year exam (current). Retinal arteriolar and venular diameters were measured from digitized images taken at both examinations and summarized as average retinal arteriolar diameter and arteriolar to venular ratio (AVR). Hypertension was defined by use of anti–hypertensive medications, systolic BP ≥160mmHg or diastolic BP ≥95mmHg at examination. Incident hypertension was defined in persons who were free of hypertension at baseline but diagnosed as hypertensive prior to or at the 5–year follow–up exam. We assessed the association between retinal arteriolar narrowing detected at the 5–year exam and past and current BP levels, as well as the association between baseline retinal arteriolar narrowing and incident hypertension over a 5–year period. Results: Among 2335 participants who were followed at the 5–year exam, 2002 (85.7%) had gradable retinal photographs to assess retinal vessel diameters. The presence of elevated current and past BP were independently associated with retinal arteriolar narrowing (p for trend <0.0001 and =0.04, respectively) and lower AVR (p for trend <0.0001 and =0.02, respectively), after adjusting for age, sex, body mass index and smoking. Of the 1302 normotensive baseline participants who were followed at the 5–year exam, 539 (41.4%) developed hypertension. After adjusting for age, sex, body mass index, smoking, glucose and serum cholesterol, persons with retinal arteriolar narrowing at baseline were 70–80 % more likely to develop incident hypertension (OR 1.8, CI 1.2–2.7 and OR 1.7, CI 1.2–2.6, comparing the narrowest vs widest quintile of retinal arteriolar diameter and AVR, respectively). This association persisted after further adjustment for baseline mean arterial BP. Conclusions: Retinal arteriolar diameter is associated with past, current and future BP levels. Persons with retinal arteriolar narrowing are more likely to have concurrently elevated BP and elevated BP in the past, and are also more likely to develop incident hypertension in the future.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • retina • imaging/image analysis: clinical