WALL-TO-LUMEN RATIO OF RETINAL ARTERIOLES IS RELATED WITH CLINIC AND 24 HOURS BLOOD PRESSURE

Objective: Wall-to-lumen ratio of retinal arterioles might be an in-vivo marker of small arteries damage. Aim of this study was to analyze retinal arteriolar structure in patients with essential hypertension and to test whether clinic and 24 h blood pressure values associated with an increased wall-to-lumen ratio of retinal arterioles. Methods: In 102 patients with essential hypertension (mean age 54 + 9.5, 38 females, 59% treated) and in 32 untreated normotensive individuals (mean age 55 + 3.3 years, 22 females, all untreated) wall-to-lumen ratio of retinal arterioles was assessed in vivo using scanning laser Doppler flowmetry (Heidelberg retina flowmeter, Heidelberg Engineering). In addition clinic and 24 h blood pressure (BP) values were measured. Results: In patients with essential hypertension a higher wall-to-lumen ratio (0.37 + 0.19 vs. 0.30 + 0.13, p = 0.05), wall thickness (11.2 + 4.6 vs. 9.3 + 3.4, p = 0.04) and wall cross-sectional area of retinal arterioles (2,747 + 1,367 vs. 2,122 + 578, p = 0.025) was observed in comparison with normotensive individuals; no differences were observed between treated and untreated hypertensive patients. Wall to lumen ratio of retinal arterioles was significantly related to clinic systolic BP (r = 0.18, p = 0.05) and diastolic BP (r = 0.19, p = 0.04) as well as to 24 h systolic BP (r = 0.24, p = 0.009) and diastolic BP (r = 0.22, p = 0.02). A significant correlation was observed between wall to lumen ratio of retinal arterioles and daytime systolic and diastolic BP (r = 0.26, p = 0.004 and r = 0.20, p = 0.026); no correlation was observed between wall to lumen ratio and mean nighttime BP or with standard deviation of 24 h, daytime and nighttime systolic and diastolic BP. Multiple regression analysis including known cardiovascular risk factors showed that 24 h, but not clinic BP is independently associated with an increased wall-to-lumen ratio of retinal arterioles.