Oxygen saturation in retinal vessels and their correlation with endothelial microparticles in diabetes mellitus and/or cardiovascular disease

R Heitmar; A D Blann

doi:10.1016/j.mvr.2022.104336

Oxygen saturation in retinal vessels and their correlation with endothelial microparticles in diabetes mellitus and/or cardiovascular disease

Microvasc Res. 2022 Jul:142:104336. doi: 10.1016/j.mvr.2022.104336. Epub 2022 Feb 7.

Authors

R Heitmar¹, A D Blann²

Affiliations

¹ Aston University, School of Optometry, College of Health and Life Sciences, Aston Triangle, B4 7ET Birmingham, UK; Centre for Vision across the Life Span, School of Applied Sciences, University of Huddersfield, Queensgate, HD1 3DH Huddersfield UK. Electronic address: R.Heitmar@hud.ac.uk.
² Centre for Vision across the Life Span, School of Applied Sciences, University of Huddersfield, Queensgate, HD1 3DH Huddersfield UK; University of Birmingham Institute for Cardiovascular Sciences, City Hospital, Birmingham B18 7QH, UK.

PMID: 35143812
DOI: 10.1016/j.mvr.2022.104336

Abstract

Purpose: Retinal oxygen supply is a critical requirement in ocular function, and when inadequate can lead to retinopathy. Endothelial dysfunction is a leading pathophysiology in diabetes and cardiovascular disease and may be assessed by endothelial microparticles (EMPs). We hypothesised links between retinal vessel oxygenation and EMPs, expecting these indices to be more adverse in those with both DM and CVD.

Methods: Plasma from 34 patients with diabetes mellitus alone (DM), 40 with cardiovascular disease (CVD) alone and 36 with DM plus CVD was probed for EMPs by flow cytometry, but also for vascular markers soluble E-selectin (sEsel) and von Willebrand factor (vWf) (both ELISA). Retinal vessel fractal dimension, lacunarity, calibres and oxygen saturation were assessed from monochromatic and dual wavelength imaging respectively, intra-ocular pressure by was measured by rebound tonometry (I-CARE).

Results: There was no difference in oxygenation (arterial p = 0.725, venous p = 0.264, arterio-venous difference 0.375) between the groups, but there were differences in EMPs (p = 0.049), vWf (p = 0.004) and sEsel (p = 0.032). In the entire cohort, and in diabetes alone, EMPs correlated with venous oxygenation (r = 0.24, p = 0.009 and r = 0.43, p = 0.011 respectively), while in DM + CVD, sEsel correlated with venous oxygenation (r = 0.55, p = 0.002) and with the arterial-venous difference (r = -0.63, p = 0.001). In multivariate regression analysis of vascular markers against retinal oximetry indices in the entire group, EMPs were positively linked to venous oxygenation (p = 0.037).

Conclusions: Despite differences in systemic markers of vascular function between DM, CVD and DM + CVD, there was no difference in arterial or venous retinal oxygenation, or their difference. However, EMPs were linked to venous oximetry, and may provide further insight into the mechanisms underlying diabetes and diabetic retinopathy.

Keywords: Blood glucose; Cardiovascular disease; Diabetes mellitus; Microparticles; Retinal vessel oxygenation; Retinal vessel reactivity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biomarkers
Cardiovascular Diseases*
Diabetes Mellitus*
Diabetic Retinopathy* / diagnosis
Humans
Oxygen
Oxygen Saturation
Retinal Vessels
von Willebrand Factor / analysis

Substances

Biomarkers
von Willebrand Factor
Oxygen