Onset and progression of diabetic retinopathy within eight years in type 2 diabetes in the Danish Registry of Diabetic Retinopathy

Abstract

Purpose : To evaluate the 8-year incidences of onset and 2-step-or-more progression of DR as well as associated markers in a national cohort of Danish patients with type 2 diabetes (T2D).

Methods : In a retrospective longitudinal cohort, we included all persons with type 2 diabetes from the Danish Registry of Diabetic Retinopathy, who had attended at least two episodes of DR-screening between 2013 and 2022. According to the worse eye at baseline, DR was classified by the International Clinical DR disease severity scale as levels 0-4. As defined between baseline and the last visit, outcomes were incident DR (level 0 to level 1-4) and 2-step-or-more progression of DR. Risk factors and possible confounders were identified in various national registries.

Results : Among 240,901 persons with T2D, median (with interquartile range) age and duration of diabetes were 66.0 (56.6-73.4) and 5.7 (1.7-11.5) years, 56.9% were male, hemoglobin A1C was 51.3 (46.0-61.0) mmol/mol, and 86.7% did not have DR at the first visit. During follow-up, the cumulative incidence and 2-step-or-more progression of DR was 6.6% and 2.0%, respectively. In multivariable Cox regression models, independent risk factors for both outcomes were male gender (HR 1.04 [95% CI 1.01-1.09] and HR 1.11 [95% CI 1.04-1.18]), duration of diabetes (HR 1.75 [95% CI 1.69-1.82] and HR 1.55 [95% CI 1.47-1.65] per 10 years), higher HbA1c (HR 2.94 [95% CI 2.58-3.35) and HR 6.31 [95% CI 5.34-7.45] for levels 100 mmol/mol or above), being never married (HR 1.15 [95% CI 1.09-1.22] and HR 1.28 [95% CI 1.18-1.40]) or widowed/divorced (HR 1.09 [95% CI 1.04-1.13] and HR 1.11 [95% CI 1.03-1.20]), use of insulin (HR 1.12 [95% CI 1.07-1.18] and 1.29 [95% CI 1.19-1.40]], and use of oral glucose-lowering drugs (HR 1.44 [95% CI 1.35-1.53] and HR 1.27 [95% CI 1.16-1.39]). Lower HbA1c (HR 0.61 [95% CI 0.54-0.69] and HR 0.60 [95% CI 0.45-0.79] for levels 39 mmol/mol or below) and use of cholesterol lowering drugs (HR 0.84 [95% CI 0.80-0.87] and HR 0.85 [95% CI 0.79-0.92]) were protective markers.

Conclusions : In a national cohort of patients with T2D, we found a low risk of onset and progression of DR and identified glycemic regulation as the strongest predictive marker.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.