Systemic circulatory influences on retinal microvascular function in middle‐age individuals with low to moderate cardiovascular risk

<jats:title>Abstract</jats:title><jats:sec><jats:title>Purpose</jats:title><jats:p>To investigate the relationship between retinal microvascular reactivity, circulatory markers for <jats:styled-content style="fixed-case">CVD</jats:styled-content> risk and systemic antioxidative defence capacity in healthy middle‐aged individuals with low to moderate risk of <jats:styled-content style="fixed-case">CVD</jats:styled-content>.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Retinal vascular reactivity to flickering light was assessed in 102 healthy participants (46–60 years) by means of dynamic retinal vessel analysis (<jats:styled-content style="fixed-case">DVA</jats:styled-content>). Other vascular assessments included carotid intima‐media thickness (C‐<jats:styled-content style="fixed-case">IMT</jats:styled-content>) and blood pressure (<jats:styled-content style="fixed-case">BP</jats:styled-content>) measurements. Total cholesterol (<jats:styled-content style="fixed-case">CHOL</jats:styled-content>), high‐density lipoprotein cholesterol (<jats:styled-content style="fixed-case">HDL</jats:styled-content>‐C), low‐density lipoprotein cholesterol (<jats:styled-content style="fixed-case">LDL</jats:styled-content>‐C), triglycerides (<jats:styled-content style="fixed-case">TG</jats:styled-content>) and blood glutathione levels in its reduced (<jats:styled-content style="fixed-case">GSH</jats:styled-content>) and oxidized (<jats:styled-content style="fixed-case">GSSG</jats:styled-content>) forms were also determined for each participant, along with Framingham risk scores (<jats:styled-content style="fixed-case">FRS</jats:styled-content>).</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Retinal arterial baseline diameter fluctuation (<jats:styled-content style="fixed-case">BDF</jats:styled-content>) was independently, significantly and negatively influenced by <jats:styled-content style="fixed-case">LDL</jats:styled-content>‐C levels (<jats:italic>β </jats:italic>= −0.53, p = 0.027). Moreover, the arterial dilation slope (Slope<jats:styled-content style="fixed-case"><jats:sub>AD</jats:sub></jats:styled-content>) was independently, significantly and positively associated with redox index (<jats:styled-content style="fixed-case">GSH</jats:styled-content>:<jats:styled-content style="fixed-case"> GSSG</jats:styled-content> ratio, <jats:italic>β </jats:italic>= 0.28, p = 0.016), while the arterial constriction slope (Slope<jats:styled-content style="fixed-case"><jats:sub>AC</jats:sub></jats:styled-content>) was significantly and negatively influenced by blood <jats:styled-content style="fixed-case">GSH</jats:styled-content> levels (<jats:italic>β </jats:italic>= −0.20, p = 0.042), and positively associated with <jats:styled-content style="fixed-case">FRS</jats:styled-content> (<jats:italic>β </jats:italic>= 0.25, p = 0.009). Venous <jats:styled-content style="fixed-case">BDF</jats:styled-content> and dilation amplitude (<jats:styled-content style="fixed-case">DA</jats:styled-content>) were also negatively influenced by plasma <jats:styled-content style="fixed-case">LDL</jats:styled-content>‐C levels (<jats:italic>β </jats:italic>= −0.83, p = 0.013; and <jats:italic>β </jats:italic>= −0.22, p = 0.028, respectively).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>In otherwise healthy individuals with low to moderate cardiovascular risk, retinal microvascular dilation and constriction responses to stress levels are influenced by systemic antioxidant capacity, and circulating markers for cardiovascular risk.</jats:p></jats:sec>