Beverage consumption and diabetic retinopathy: a two-sample Mendelian randomization study

Abstract

Abstract Background Observational studies on the association between beverage intake and diabetic retinopathy (DR) remain controversial. We aimed to investigate the causal relationship between beverage consumption (coffee, juice, yogurt, tea, alcohol, milk) and DR via the two-sample Mendelian randomization (MR) approach. Methods We use genome-wide association study summary level data in this study, selecting single nucleotide polymorphisms (SNPs) as the instrumental variables, taking inverse variance weighted as the main analysis method and further verifying its sensitivity by MR‒Egger, MR-PRESSO and weighted median. The heterogeneity test was conducted by the MR‒Egger intercept test, Cochrane’s Q test, MR-PRESSO global test, leave-one-out and funnel plot. Results A total of 40, 14, 12, 41, 34 and 30 SNPs were selected to represent coffee, juice, yogurt, tea, alcohol and milk intake from the MRC IEU and GSCAN. The DR data were extracted from the FinnGen consortium with 14584 cases and 202082 controls. Coffee can increase the risk of DR (IVW, odds ratio (OR) [confidence intervals (CI)] 1.39 [1.02–1.90], P = 0.037), and the result was consistent with background diabetic retinopathy (BKG_DR) (IVW, OR [CI] 2.56 [1.20–5.47], P = 0.015) and proliferative diabetic retinopathy (PDR) (IVW, OR [CI] 1.75 [1.20–2.56], P = 0.004). In addition,other beverage intake were not found to be causally related to DR. Conclusion Genetic level evidence suggests that coffee consumption is a risk factor for DR and should be limited in diabetic mellitus patient daily life, which provides advice on habitual diet management for patients with diabetic mellitus