Background: Kidney stone is a common kidney disease resulting from various genetic, metabolic, dietary, and environmental factors. This cross-sectional population-based investigation aimed to evaluate if non-alcoholic fatty liver disease (NAFLD) is associated with kidney stones.

Methods: This study was performed on the baseline data of the PERSIAN (Prospective Epidemiological Research Studies in IrAN) Kavar cohort study (PKCS), and 4,909 individuals were included in the analysis. NAFLD and kidney stones were determined based on a structured questionnaire and confirmed with ultrasonographic findings. We used logistic regression to estimate the odds ratio (OR) and 95% confidence interval (CI) of the association between NAFLD and kidney stones.

Results: The prevalence of NAFLD and kidney stones in the study population were 14.75% and 28.52%, respectively. In this study, 24.43% of patients with a kidney stone and 10.89% of the other subjects suffered from NAFLD (P-value<0.001). Multivariate logistic regression analysis revealed a positive association between NAFLD and kidney stone disease (OR=2.58, 95% CI: 2.18-3.06, P-value<0.001) after adjusting for age, sex, education, smoking status, alcohol intake, diabetes, hypertension, body mass index, and physical activity. This association was significantly more prominent in alcohol drinkers (OR=8.33 vs. 2.46, P for interaction: 0.013) compared to the others.

Conclusion: The current research demonstrates a positive association between NAFLD and kidney stone disease.