Retinal microvascular parameters are not associated with reduced renal function in a study of individuals with type 2 diabetes

Gareth J Mckay,Euan N Paterson,Emanuele Trucco,Alexander P Maxwell,Ruixuan Wang,Christopher C Cardwell,Alexander S Doney,Stephen Hogg,Thomas J Macgillivray

doi:10.1038/s41598-018-22360-3

Gareth J Mckay, Euan N Paterson + Show 7 more

Open Access

https://doi.org/10.1038/s41598-018-22360-3

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Abstract

The eye provides an opportunistic “window” to view the microcirculation. There is published evidence of an association between retinal microvascular calibre and renal function measured by estimated glomerular filtration rate (eGFR) in individuals with diabetes mellitus. Beyond vascular calibre, few studies have considered other microvascular geometrical features. Here we report novel null findings for measures of vascular spread (vessel fractal dimension), tortuosity, and branching patterns and their relationship with renal function in type 2 diabetes over a mean of 3 years. We performed a nested case-control comparison of multiple retinal vascular parameters between individuals with type 2 diabetes and stable (non-progressors) versus declining (progressors) eGFR across two time points within a subset of 1072 participants from the GoDARTS study cohort. Retinal microvascular were measured using VAMPIRE 3.1 software. In unadjusted analyses and following adjustment for age, gender, systolic blood pressure, HbA1C, and diabetic retinopathy, no associations between baseline retinal vascular parameters and risk of eGFR progression were observed. Cross-sectional analysis of follow-up data showed a significant association between retinal arteriolar diameter and eGFR, but this was not maintained following adjustment. These findings are consistent with a lack of predictive capacity for progressive loss of renal function in type 2 diabetes.

Highlights

Type 2 diabetes mellitus is a disease characterised by micro- and macrovascular complications in 30–50% of people with the condition[1] and is the commonest cause of end-stage renal disease (ESRD), accounting for approximately 45% of incident and 38% of prevalent ESRD in the United States[2]
Retinal microvascular parameters have been suggested to reflect systemic microvascular damage resulting from renal dysfunction[13], and in population-based studies, reduced estimated glomerular filtration rate (eGFR) has been associated with both narrower retinal arteriolar[14,15,16,17,18,19,20,21] and venular calibre[14,16,22,23], but to date the evidence has been limited and the findings reported, inconsistent
Reductions in eGFR can occur in the presence or absence of albuminuria[38] and may have entirely independent associations with retinal vascular morphology

Summary

Introduction

Type 2 diabetes mellitus is a disease characterised by micro- and macrovascular complications in 30–50% of people with the condition[1] and is the commonest cause of end-stage renal disease (ESRD), accounting for approximately 45% of incident and 38% of prevalent ESRD in the United States[2]. Retinal microvascular parameters have been suggested to reflect systemic microvascular damage resulting from renal dysfunction[13], and in population-based studies, reduced eGFR has been associated with both narrower retinal arteriolar[14,15,16,17,18,19,20,21] and venular calibre[14,16,22,23], but to date the evidence has been limited and the findings reported, inconsistent. Oxidative damage is increased and there is a proliferation of inflammatory mediators such as interleukin-6 (IL-6) and c-reactive protein (CRP)[8,24] Several of these biochemical changes are associated with alterations in retinal vascular calibre, e.g. IL-6 and CRP25,26, serum glucose[26], and nitric oxide inhibition[27]. The aim of this study was to examine the prognostic potential of RVP to predict eGFR decline in a large prospective cohort of type 2 diabetes

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