Higher glucose level and systemic oxidative stress decrease the mean velocity index of the retinal artery during flickering light stimulation in type 1 diabetes.
OBJECTIVE
To determine whether higher glucose level and systemic oxidative stress decrease mean velocity (MV) index of the central retinal artery (CRA) during flickering light stimulation in type 1 diabetes (T1D).


METHODS
The study was performed in the period from 2008 to 2015 at the University Eye Clinic in Ljubljana. 41 patients with T1D and 37 participants without diabetes were included. MV in the CRA was measured using Doppler ultrasound diagnostics in basal conditions and during 8 Hz flickering light irritation. The plasma levels of glucose, fructosamine, 8-hydroxy-2'-deoxyguanosine (8-OHdG), triglycerides, cholesterol, and low-density lipoprotein (LDL) were measured.


RESULTS
Patients with T1D had significantly higher levels of blood glucose (P<0.001), fructosamine (P<0.001), and 8-OHdG (P<0.001), but there were no significant differences in triglycerides (P=0.108), cholesterol (P=0.531), and LDL (P=0.645) between the groups. Patients with T1D also had a significantly lower MV index in the CRA (1.11±0.15 vs 1.24±0.23; P=0.010). In the T1D group, a significant negative correlation was found between the level of glucose (r=0.58; P<0.001), fructosamine (r=0.46; P=0.003), 8-OHdG (r=0.48; P=0.002) and the MV index in the CRA. At the same time, in this group fructosamine and 8-OHdG levels had a separate effect on the MV index (adjusted R2=0.38, P<0.001).


CONCLUSIONS
Higher glucose levels, the medium-term glucose level, and systemic oxidative stress could importantly reduce retinal vasodilatation during flickering light irritation in patients with T1D.
Vladimir Debelić, University Eye Clinic, University Medical Center in Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia, vladimir.debelic@masicom.net.
Vladimir
V
Debelić
Brigita
B
Drnovšek Olup
Bogomir
B
Žižek
Milan
M
Skitek
Aleš
A
Jerin
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008029:Lighting / Q000009:adverse effects*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D012161:Retinal Artery / Q000503:physiopathology*
D001786:Blood Glucose; D008055:Lipids; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine