Oily fish intake reduces the risk of nephrolithiasis: A cross-sectional and Mendelian randomization study

PURPOSE: The study aimed to explore the relationship between different types of meat intake and the risk of nephrolithiasis using NHANES data and Mendelian randomization (MR) techniques. MATERIALS AND METHODS: This study was a cross-sectional study supplemented by a two-sample MR approach. Weighted multivariable-adjusted logistic regression analysis was conducted on the gathered data to assess the link between meat consumption and the risk of developing kidney stones. Subsequently, a two-sample MR study was conducted utilizing genome-wide association study (GWAS) summary statistics to explore the causal link between meat intake and nephrolithiasis. The main inverse variance weighted (IVW) method along with supplementary MR techniques were applied to validate the causal relationship. RESULTS: Prospective study analysis demonstrated a negative relationship between nephrolithiasis risk and salmon intake (OR = 0.861, 95% CI: 0.745 - 0.996) and a positive relationship with cod intake (OR = 1.288, 95% CI: 1.040 - 1.596). Mendelian randomization results showed that oily fish intake was negatively associated with nephrolithiasis (OR = 0.67, 95% CI: 0.51 - 0.89), while non-oily fish (OR = 1.55, 95% CI: 1.05 - 2.28) and pork (OR = 1.54, 95% CI: 1.04 - 2.28) intake were associated with an increased risk. CONCLUSION: Findings indicate that oily fish intake may lower the risk of kidney stone and highlight the significance of specific dietary modifications for preventing and controlling nephrolithiasis.