# Assessing the relationship between gout and the risk of cataract in community-dwelling older adults: mediation and moderation analysis

## TL;DR

This study found that gout increases the risk of cataract, especially senile cataract, and that glucocorticoid use may influence this relationship.

## Contribution

The study identifies gout as an independent risk factor for cataract and reveals a mediating role of glucocorticoid use.

## Key findings

- Gout increases the risk of cataract (hazard ratio 1.69) and remains significant after adjusting for covariates.
- Glucocorticoid use interacts with gout to influence senile cataract risk.
- About 2.4% of the gout-cataract effect is mediated by glucocorticoid use.

## Abstract

This study aimed to assess whether gout is a risk for cataract and identify important factors contributing to the association.

A total of 381,402 individuals from the UK Biobank were enrolled at baseline (2006–2010). Cataract was ascertained using hospital inpatient and self-reported data until early 2021. Gout was determined by ICD-9, ICD-10, self-report, and medication at baseline. The Cox regression model was used to estimate the hazard ratio (HR) and 95% confidence intervals (CIs) for the risk of cataract.

The risk of cataract was significantly increased in patients with gout (HR, 1.69; 95% CI, 1.48–1.94; p < 0.001), and this association was attenuated but remained significant after additional adjusting for other covariates (HR, 1.14; 95% CI, 1.04–1.26; p = 0.006). In addition, we observed a significant interaction effect between gout and glucocorticoids (GCC) use for senile cataract (p = 0.04). In the sensitivity analysis, we stratified the population by sex, diabetes mellitus (DM), and GCC use. We noticed that gout remains a risk factor for cataract in both sexes and in patients with or without GCC use. Finally, we tested the mediation effect of GCC; we observed that 2.4% of the effect between gout and cataract and 3% of the effect between gout and senile cataract was mediated by GCC use.

This cohort study found that gout was an independent risk factor for cataract, with a significant impact on senile cataract. GCC use modified the effect of gout on the development of senile cataract (interaction effect), thus prescribing GCC to patients with gout should be actively monitored for cataract development.