Critical assessment of the reported bidirectional associations between gallstone, non-alcoholic fatty liver, and kidney stone diseases.

The recent article by Jiang published in reports substantial bidirectional associations between gallstone disease (GSD), non-alcoholic fatty liver disease (NAFLD), and kidney stone disease (KSD), based on multicenter cross-sectional studies and a systematic review with meta-analysis. While the findings have the potential to significantly impact clinical and preventive strategies, several methodological issues merit closer examination. This letter critiques key aspects of the study, including sample population heterogeneity, potential confounding variables, and the reliance on cross-sectional data that may limit causal inferences. We also discuss the generalizability of these results to broader populations given the study's focus on the Chinese demographic. By addressing these concerns, we suggest a more nuanced interpretation of the associations between GSD, NAFLD, and KSD, advocating for longitudinal studies to validate these findings and enhance their applicability in global health contexts.