Non-alcoholic fatty liver disease and the risk of urolithiasis A systematic review and meta-analysis

There is growing evidence that nonalcoholic fatty liver disease (NAFLD) is associated with a higher risk of urolithiasis, but it has not yet been determined that this association is reproducible and consistent across different studies. We performed a systematic review and meta-analysis of these studies to examine the association between NAFLD and the risk of urolithiasis. We searched PubMed, EMBASE, and Google scholar using terms "fatty liver" (OR "non-alcoholic fatty liver disease" OR "nonalcoholic steatohepatitis" OR "NAFLD" OR "NASH") AND "urolithiasis" (OR "nephrolithiasis" OR "kidney stone" OR "urinary calculi" OR "renal colic" OR "urologic disease"). Observational studies in which NAFLD and urolithiasis were diagnosed by either ultrasonography or computerized tomography were included. A total of 7 observational studies with 226,541 individuals (24.7% with NAFLD) and 19,184 urolithiasis (8.5%). NAFLD was significantly associated with an increased risk of urolithiasis (random effect odds ratio, OR 1.73, 95% confidence interval, CI 1.24-2.40, I-2=94.5%). Sensitivity analyses revealed the robustness of the results. Egger test and Begg test suggested no publication bias (P>.05). NAFLD is associated with an increased risk of urolithiasis. Therefore, patients with NAFLD should be carefully monitored for the development of urolithiasis.