The level of urine dipstick proteinuria and its relation to the risk of incident cholelithiasis

BACKGROUND: Previous studies have suggested the potential association between renal diseases and gallstone. The extent of proteinuria is recognized as a marker for the severity of chronic kidney disease. However, little data is available to identify the risk of incident gallstone according to the level of proteinuria. METHODS: Using a data of 207,356 Koreans registered in National Health Insurance Database, we evaluated the risk of gallstone according to the levels of urine dipstick proteinuria through an average follow-up of 4.36 years. Study subjects were divided into 3 groups by urine dipstick proteinuria (negative: 0, mild: 1+ and heavy: 2+ or greater). Multivariate Cox-proportional hazard model was used to assess the adjusted hazard ratios (HRs) and 95% confidence interval (CI) for incident cholelithiasis (adjusted HRs [95% CI]) according to urine dipstick proteinuria. RESULTS: The group with higher urine dipstick proteinuria had the worse metabolic, renal and hepatic profiles, which were similarly observed in group with incident cholelithiasis. Heavy proteinuria group topped at incidence of cholelithiasis (2.39%), followed by mild (1.54%) and negative proteinuria group (1.39%). Analysis for multivariate Cox-proportional hazard model indicated that heavy proteinuria group had the higher risk of cholelithiasis than other groups (negative: reference, mild proteinuria: 0.97 [0.74 -1.26], and heavy proteinuria: 1.46 [1.09-1.96]). CONCLUSION: Urine dipstick proteinuria of 2+ or greater was significantly associated with the increased risk for incident gallstone.