Background: This study aimed to investigate the dose‒response association and potential causal effect between VAT volume and nephrolithiasis risk.
Methods: Multivariable logistic regression models were used to estimate the association between nephrolithiasis risk and VAT quartiles. Restricted cubic splines (RCSs) were employed to investigate potential nonlinear associations between visceral adipose tissue (VAT) and the likelihood of developing nephrolithiasis. A Mendelian randomization analysis was conducted to assess the causal relationship between VAT volume and nephrolithiasis risk.
Results: Participants in the highest VAT quartile demonstrated a significantly greater risk of nephrolithiasis than did those in the lowest quartile across all the models: crude mode (OR [95% CI], 3.00 [1.78, 5.07]), model 1 (OR [95% CI], 2.24 [1.28, 3.92]), model 2 (OR [95% CI], 2.18 [1.24, 3.83]), and model 3 (OR [95% CI], 1.95 [0.99, 3.82]). The RCS analysis revealed a linear relationship between VAT volume and nephrolithiasis (P-nonlinear=0.443). Mendelian randomization analysis provided consistent evidence that higher VAT volume was causally associated with increased nephrolithiasis risk (OR [95% CI], 1.03 [1.02, 1.04]; P<0.001).
Conclusions: This study demonstrated a positive linear causal association between VAT volume and nephrolithiasis risk.