2.4 AMBULATORY AORTIC STIFFNESS, INDEPENDENTLY OF STATIC, ASSOCIATES WITH NARROWER RETINAL ARTERIOLAR CALIBERS IN HYPERTENSIVES: THE SAFAR STUDY

Abstract

Background: Arterial stiffness measured under static conditions reclassifies significantly cardiovascular (CV) risk and associates with organ damage, including narrower retinal arterioles. However, arterial stiffness exhibits diurnal variation, thus single static stiffness recordings do not correspond to the “usual” 24 hr, awake and asleep average arterial stiffness. We aimed to test the hypothesis that ambulatory 24 hr, awake and asleep aortic (a) pulse wave velocity (PWV) associate with retinal vessel calibers, independently of confounders and of static arterial stiffness, in hypertensive individuals free from diabetes and CV disease. Methods: Digital retinal images were obtained (181 individuals, age: 53.9 ± 10.7 years, 55.2% men) and retinal vessel calibers were measured with validated software to determine central retinal arteriolar and venular equivalents (CRAE and CRVE, respectively); ambulatory (24 hr, awake, asleep) and static office aPWV were estimated by Mobilo-O-Graph; and static office carotid-femoral (cf) PWV by SphygmoCor. Results: Regression analysis performed in 320 gradable retinal images showed that, after adjustment for confounders: (i) ambulatory aPWV was significantly associated with narrower retinal arterioles but not with venules; (ii) asleep aPWV had stronger associations with CRAE than awake aPWV; (iii) both ambulatory aPWV and cfPWV were associated mutually independently with narrower retinal arterioles; aPWV introduction in the model of cfPWV, improved model’s R2 (p = 0.012). Similar discriminatory ability of 24 hr aPWV and of cfPWV to detect the presence of retinal arteriolar narrowing was found. Conclusion: Ambulatory aPWV, estimated by an operator-independent method, provides additional information to cfPWV regarding the associations of arterial stiffness with the retinal microcirculation.