Association between albuminuria and retinal microvascular dysfunction in type 2 diabetes with and without hypertension

Abstract

Background: Studies assessing the concordance of albuminuria and retinal microvascular dysfunction (RMD) in type 2 diabetes (T2D) have yielded inconsistent results. Similar to ethnicity, hypertension may be a potential explanatory variable. We compared the association between albuminuria and RMD in West Africans with T2D with and without hypertension. Materials and methods: This was a cross-sectional study among 177 systematically sampled Ghanaians with T2D aged ≥ 35 years. Albuminuria was based on urinary albumin-creatinine ratio≥30 mg/g. Retinal images were analyzed and graded according to the Early Treatment Diabetic Retinopathy Study criteria. Logistic regression was used to examine the associations of albuminuria and RMD with adjustments for age, sex, socioeconomic status, diabetes duration, HbA1c, smoking, systolic blood pressure (BP), BMI, and total cholesterol. Results: RMD was more prevalent in individuals with albuminuria than in those without albuminuria (41.7% vs. 24.0%, p = 0.026). In the fully adjusted model, albuminuria remained significantly associated with RMD (odds ratio 2.41[95% CI:1.00−5.80], p = 0.049); the association between albuminuria and RMD was more pronounced in individuals with hypertension (3.10 [1.01−9.50], 0.048) than without hypertension (1.70[0.33 −8.77],0.523). In analyses stratified by BP control, albuminuria was significantly associated with RMD in individuals with suboptimal BP (2.76[1.07−7.14], 0.037) but not in individuals with optimal BP (0.24[0.00 −17.04],0.512) Conclusion: Our study shows positive associations between albuminuria and RMD among West Africans with T2D, with the strength of association, accentuated in individuals with hypertension/suboptimal BP. Future studies could further characterize the role of hypertension in the associations between albuminuria and RMD.