Abstract
Background: Observational studies have reported a link between coffee consumption and diabetic retinopathy (DR), but the causal relationship remains a subject of debate. To explore these causal associations, we conducted a Mendelian randomization (MR) study.
Methods: We utilized seven publicly accessible genome-wide association studies (GWAS) datasets related to coffee intake (ukb-b-5237) and DR (finn-b-DM_RETINOPATHY, finn-b-H7_RETINOPATHYDIAB, finn-b-DM_RETINOPATHY_EXMORE, finn-b-DM_RETINA_PROLIF, finn-b-H7_RETINOPATHYDIAB_PROLIF, and finn-b-H7_RETINOPATHYDIAB_BKG). MR analyses were performed using inverse variance weighted (IVW), weighted median, MR-Egger regression, and weighted mode estimates.
Results: Employing 40 single-nucleotide polymorphisms (SNPs) of genome-wide significance as instrumental variables for coffee intake, our study revealed a positive correlation between genetically predicted coffee consumption and the risk of DR (OR= 1.39, 95% CI: 1.02 to 1.90, p = 0.037; OR=2.25, 95% CI: 1.21 to 4.20, p = 0.011; OR= 1.66, 95% CI: 1.17 to 2.35, p = 0.004; OR= 1.75, 95% CI: 1.20 to 2.56, p = 0.004; OR= 2.79, 95% CI: 1.08 to 7.23, p = 0.035; OR= 2.48, 95% CI: 1.16 to 5.29, p = 0.019). These results were consistent across various sensitivity analyses and free from pleiotropy.
Conclusions: Our findings indicate a positive association between coffee intake and the risk of DR, as determined by genetic data. These correlations warrant serious consideration in clinical settings.