# Causal Associations of Smoking, Alcohol, Obesity, Sedentary Behavior, Hypertension, and Hyperglycemia With Retinal Vein Occlusion: A Mendelian Randomization Study

## TL;DR

This study uses genetic data to find that alcohol consumption and high blood sugar may cause retinal vein occlusion, a leading cause of blindness.

## Contribution

The study provides new genetic evidence identifying alcohol and hyperglycemia as causal risk factors for retinal vein occlusion.

## Key findings

- Genetic predisposition to alcohol consumption is associated with increased RVO risk (OR 1.124, P=0.037).
- Genetic predisposition to hyperglycemia is linked to increased RVO risk (OR 1.108, P=0.012).
- No significant causal associations were found for smoking, obesity, sedentariness, or hypertension.

## Abstract

Retinal Vein Occlusion (RVO) is a common and main cause of blindness. Causal, possible risk variables must be identified to develop preventative strategies for RVO. Thus, we decided to evaluate whether smoking, alcohol, obesity, sedentary behaviour, hypertension, and hyperglycemia are associated with increased risk of RVO.

The data sources of Mendelian Randomization (MR) study included FinnGen consortium and the original GWAS article. A total of 130,604 cases with RVO from FinnGen consortium and 12,136 cases with RVO from the original GWAS article. The exposures of this MR study included smoking, alcoholic consumption, obesity, sedentariness, hypertension, and hyperglycemia. The outcome of this MR study was RVO.

Genetic predispositions to alcohol consumption (OR (odds ratio), 1.124; 95%CI, 1.007-1.254; P=0.037) and hyperglycemia (OR, 1.108; 95%CI, 1.023-1.200; P=0.012) were associated with increased risks of RVO in FinnGen. There were no significant associations of genetically predicted consumption of smoking (OR, 1.037; 95%CI, 0.341-3.155; P=0.949), obesity (OR, 1.045; 95%CI, 0.975-1.119; P=0.213), sedentariness (OR, 1.022; 95%CI, 0.753-1.38-; P=0.888), or hypertension (OR, 0.944; 95%CI, 0.848-1.051; P=0.290) with RVO.

This MR analysis provides genetic evidence that increased alcohol consumption and hyperglycemia may be causal risk factors for RVO. In addition, no genetic evidence in this MR analysis supported that there were causal associations between smoking, sedentariness, obesity and hypertension with RVO.