Carotid stiffness is associated with retinal microvascular dysfunction—The Maastricht study

Abstract

Objective: This study investigated whether arterial stiffening is a determinant of subtle retinal microvascular changes that precede diabetic retinopathy. Research design and methods: This study used cross-sectional data from the Maastricht Study, a type 2 diabetes-enriched population-based cohort study. We used multivariable linear regression analysis to investigate, in individuals without and with type 2 diabetes, the associations of carotid distensibility coefficient and carotid-femoral pulse wave velocity with retinal microvascular diameters and flicker light-induced dilation and adjusted for cardiovascular and lifestyle risk factors. Results: The retinal microvascular diameter study population consisted of N = 2434 participants (51.4% men, mean ± SD age 59.8 ± 8.1 years, and 28.1% type 2 diabetes). No measures of arterial stiffness were significantly associated with microvascular diameters. Greater carotid distensibility coefficient (i.e., lower carotid stiffness) was significantly associated with greater retinal arteriolar flicker light-induced dilation (per standard deviation, standardized beta [95% CI] 0.06 [0.00; 0.12]) and non-significantly, but directionally similarly, associated with greater retinal venular flicker light-induced dilation (0.04 [−0.02; 0.10]). Carotid-femoral pulse wave velocity (i.e., aortic stiffness) was not associated with retinal microvascular flicker light-induced dilation. The associations between carotid distensibility coefficient and retinal arteriolar and venular flicker light-induced dilation were two- to threefold stronger in individuals with type 2 diabetes than in those without. Conclusion: In this population-based study greater carotid, but not aortic, stiffness was associated with worse retinal flicker light-induced dilation and this association was stronger in individuals with type 2 diabetes. Hence, carotid stiffness may be a determinant of retinal microvascular dysfunction.