Abstract P323: Arterial Stiffness and Retinal Vessel Diameters: The Atherosclerosis Risk in Communities Study - Neurocognitive Study (ARIC-NCS)
Authors: Snyder Michelle L , Klein Barbara E , Klein Ronald , Sharrett A. Richey , Nambi Vijay , Wong Tien Y , Palta Priya , Tanaka Hirofumi 
Published: July 2021

Background:
The retinal microvasculature measured non-invasively by fundus photography enables examination of the role of small blood vessels in cerebrovascular disease since changes in retinal vessels may mimic that of cerebral arterioles. The association of arterial stiffness measured by pulse wave velocity (PWV) and retinal vessel diameters in a population sample is unknown, and evaluation of segment-specific PWV and retinal vessel diameters has not been conducted.

Objectives:
To quantify the cross-sectional association of PWV with retinal vessel diameters in a population of older adults.

Methods:
We examined data on PWV and retinal photography in 1,538 adults (853 females; mean age 77 years) from the population-based ARIC-NCS after excluding 43 participants with retinal diseases and 46 with missing covariates. Technicians used the Omron VP-1000 plus system following a standardized protocol to measure carotid femoral (cfPWV), brachial-ankle (baPWV), heart-femoral (hfPWV) and femoral-ankle (faPWV) twice and averaged the results. Non-mydriatic retinal fundus photography of both eyes were obtained and digital images were centrally processed with computer software to calculate central retinal arteriolar equivalent (CRAE) and central retinal vein equivalent (CRVE), which reflect diameters of retinal arterioles and venules, respectively. We used data from a randomly selected eye, and if missing, the non-missing eye was used (n=490). The relationship of PWV and CRAE and CRVE was assessed by multivariable linear regression adjusted for age, gender, race, hypertension, diabetes and smoking (current or former vs. never).

Results:
PWV was not associated with CRAE. The association of faPWV and CRVE was modified by gender. Among males, faPWV (cm/sec) was negatively associated with CRVE (beta= -0.01 μm, 95% confidence interval (CI): -0.02 to -0.006). This pattern was not observed among females. The association of baPWV and CRVE was modified by gender and smoking in which baPWV was only associated with CRVE in male smokers (current and former). Among male smokers, baPWV (cm/sec) was negatively associated with CRVE (beta= -0.002 μm, CI: -0.02 to -0.008). Interactions were robust to additional adjustment for systolic blood pressure, heart rate and body mass index. No association was observed between cfPWV and hfPWV with CRVE.

Conclusion:
Arterial stiffness was not associated with retinal arteriole diameters in older adults, but peripheral measures of arterial stiffness were associated with retinal venular diameters in males and male smokers. Whether peripheral stiffness plays a role in microvascular changes or has a shared mechanistic pathway with smoking among males requires additional investigation. The different associations of PWV and retinal measures suggest diverse pathogenic processes are involved in macrovascular and microvascular changes preceding end-organ damage.