Abstract
IntroductionDynamic retinal vessel analysis (DVA) is a new non-invasive method to quantify microvascular endothelial dysfunction by flicker light-induced dilatation (FID). FID has been shown to be impaired in type 2 diabetes as well as heart failure. The aim of the study was to analyze FID in healthy active versus healthy sedentary and cardiovascular (CV) risk patients in addition to corresponding static vessel diameters.MethodsThirty-one healthy active (HA, mean age 60 ± 8 years), 33 healthy sedentary individuals (HS, 59 ± 7 years) and 76 sedentary patients with increased CV risk (SR, 58 ± 6 years) were included in this cross-sectional study. Group differences in CV risk factors and cardiorespiratory fitness, maximal arteriolar (ADmax) and venular (VDmax) dilatation as well as the arteriolar (AFarea) and venular (VFarea) area under the flicker curve were analyzed. The central retinal arteriolar and venular diameters were used to calculate the arteriolar-to-venular diameter ratio (AVR).ResultsHS [ADmax = 3.5 (2.1)%; AFarea = 48.2 (31.9)%∗s] showed higher FID compared to SR [ADmax = 2.7 (1.8)%, p = 0.021; AFarea = 34.5 (26.5)%∗s, p = 0.006] and HA [AFarea = 32.8 (23.1)%∗s, p = 0.029]. HA and SR did not significantly differ. HA had a higher AVR (0.87 ± 0.05) compared to HS (0.83 ± 0.04, p < 0.001) with further deterioration in SR (0.79 ± 0.05, p < 0.001). Interestingly, 28 participants had impaired FID but normal AVR and 43 participants had normal FID but impaired AVR.DiscussionFID can differentiate between sedentary low and high risk individuals. However, FID in healthy active persons (HA) seemed impaired with a concomitant higher AVR. We postulate that lower FID in HA may be explained by predilatated arterioles and a reduced dilatation reserve. We recommend combination of FID with analysis of retinal vessel diameters to differentiate functional non-responders from manifest microvascular endothelial dysfunction and, thereby, improve microvascular risk stratification in a personalized medicine approach.Clinical Trial RegistrationClinicalTrials.gov: NCT02796976 (https://clinicaltrials.gov/ ct2/show/NCT02796976).
Highlights
Dynamic retinal vessel analysis (DVA) is a new non-invasive method to quantify microvascular endothelial dysfunction by flicker light-induced dilatation (FID)
Healthy sedentary showed higher FID compared to sedentary patients at risk (SR) [healthy sedentary (HS): ADmax = 3.5 (2.1)%; arteriolar area under the flicker curve (AFarea) = 48.2 (31.9)%∗s vs. SR: ADmax = 2.7 (1.8)%, p = 0.021; AFarea = 34.5 (26.5)%∗s, p = 0.006] and healthy active persons (HA) [HA: AFarea = 32.8 (23.1)%∗s, p = 0.029] (Figure 2 and Table 3)
No significant associations were observed for body mass index (BMI), 24 h systolic and diastolic blood pressure, fasting glucose, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride, physical activity (PA) or fitness
Summary
Dynamic retinal vessel analysis (DVA) is a new non-invasive method to quantify microvascular endothelial dysfunction by flicker light-induced dilatation (FID). FID has been shown to be impaired in type 2 diabetes as well as heart failure. Dynamic retinal vessel analysis is a new non-invasive diagnostic tool to assess microvascular endothelial dysfunction. Flicker light-induced dilatation (FID) of arterioles seem to reflect cardiovascular (CV) risk at a subclinical stage. Nägele et al showed that FID is reduced in patients with CV risk factors compared to healthy controls with further deterioration in heart failure patients (Nagele et al, 2018b). Sörensen et al (2016) demonstrated reduced FID in patients with prediabetes compared to healthy individuals with further impairments in patients with manifest type 2 diabetes (Sörensen et al, 2016). No studies to date have combined dynamic and static retinal vessel analysis in an individual patientorientated approach
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
