Retinal microvascular markers in type 2 diabetes subphenotypes and latent autoimmune diabetes of adults

PURPOSE: To estimate if newly diagnosed patients with different subphenotypes of type 2 diabetes (T2DM) or latent autoimmune diabetes of adults (LADA) differ with respect to subclinical retinal microvascular structure or diabetic retinopathy (DR).

METHODS: This population-based, cross-sectional study of 340 patients (675 eyes) classified patients with recently diagnosed T2DM in different subphenotypes according to beta cell function and insulin sensitivity in to; classical (n = 218), hyperinsulinaemic (n = 86), insulinopenic (n = 20), or LADA (n = 16). Retinal 6-field images were graded according to the International Clinical DR Severity Scale by a retinal expert. Retinal microvascular structures were analysed in eyes by a semiautomatic software.

RESULTS: Median age and duration of diabetes were 58.1 (49.9; 65.5) and 0.9 (0.5; 2.4) years, respectively, and 56.8% were male. In a multivariate linear mixed model regression analysis of eyes without DR (n = 570), there was no statistically significant difference in retinal venular or arteriolar width between subtypes and patients with classical T2DM. In addition, eyes from different subphenotypes did not differ according to vessel density, tortuosity or fractal dimension. In a multivariate logistic regression model adjusted for age, sex, HbA1c, diabetes duration, body mass index, mean arterial blood pressure and history of cardiovascular disease, there was a tendency towards persons with hyperinsulinaemic T2DM to be more likely to have DR (OR 1.97, 95% CI 0.95; 4.09) compared to classical T2DM.

CONCLUSION: We found no difference in retinal microvascular structure in patients with newly diagnosed subtypes of T2DM. However, DR may be more prevalent in newly diagnosed patients with hyperinsulinaemic T2DM compared to individuals with classical T2DM.