Abstract
Purpose: :
To determine whether changes in coronary reactivity are associated with changes in retinal blood vessel diameter and reactivity using a similar stimulus in individuals with prediabetes and type 2 diabetes. We hypothesized that individuals with prediabetes and type 2 diabetes would be associated with impaired coronary reactivity and that this would be associated with impaired retinal vessel function.
Methods: :
Middle aged to older individuals with pre-diabetes (n=15), type 2 diabetes (n=22) and healthy age matched controls (n=14) were recruited. Retinal reactivity was measured using the Dynamic Vessel Analyzer (DVA) in the dominant eye and coronary reactivity was measured using transthoracic echocardiography ultrasound during a 5-minute hyperoxia (100% oxygen) stimulus. We calculated the overall percent change in retinal vessel diameter and coronary velocity from baseline.
Results: :
Although type 2 diabetics compared to controls had impaired retinal artery responses to hyperoxia (-.04± .86% vs. -3.81 ± 1.41%, P=.03) and smaller artery-vein ratios (AVR) (.83± .02 vs. .90 ± .02, P=.03), coronary velocity responses to hyperoxia were not significantly different between the three groups. Individuals with prediabetes compared to controls had non-significant impairments in coronary and retinal reactivity. Coronary function was significantly correlated to AVR (r= -.35, P=.01) and retinal artery diameter (r= -.50, P=.00).
Conclusions: :
Retinal but not coronary reactivity to a hyperoxic stimulus is impaired with diabetes; however, smaller retinal artery diameters and AVR are associated with impaired coronary function. Funded by Dean’s Feasibility Grant/PA Tobacco Settlement Funds. DVA funded by PSIDO Equipment Grant, PA Lions Club, PSHMC Research Grant, Departments of Heart and Vascular Institute, Neurology, and Ophthalmology.
Keywords: retina • diabetes • oxygen