Causal Effects of Lifestyle and Dietary Factors on Urinary Stone Risk in a Genetic and Population-Based Study

This study evaluated how lifestyle habits and dietary factors influence urinary stone risk by integrating Mendelian randomization (MR) analysis with data from the National Health and Nutrition Examination Survey (NHANES). Instrumental variables were obtained from genome-wide association study datasets, while urinary stone outcomes were sourced from the FinnGen database. The primary MR analysis used the inverse-variance weighted approach, and additional MR methods verified the robustness of the findings. NHANES data further assessed the relationships between lifestyle characteristics, dietary patterns, and kidney stone occurrence. The MR analysis demonstrated that higher pre-tax income was inversely associated with urinary stone risk. Greater consumption of fresh fruits and tea, along with increased intake of potassium and vitamin E, also correlated with a lower likelihood of stone formation. NHANES analysis identified sleep deprivation, sleep disorders, depression, and elevated body mass index as significant risk factors for nephrolithiasis. In addition, pro-inflammatory dietary patterns characterized by higher Dietary Inflammatory Index scores increased stone risk, whereas adherence to HEI-2020, DASH, and aMED dietary patterns showed protective associations. These findings provide further insight into modifiable dietary and lifestyle determinants of urinary stone disease and may support the development of preventive and therapeutic strategies.