Prevalence of biliary lithiasis in a Sicilian population of chronic renal failure patients

Background. The aim of this study was to evaluate the prevalence of biliary lithiasis (BL) and associated risk factors in a population of undialysed patients with chronic renal failure (CRF), and to compare these with findings we had obtained previously in chronic haemodialysis (HD) patients and in subjects from the general population located in the same geographic region. Methods. A toal of 118 CRF patients on conservative treatment were included in the study. In all subjects, we measured several clinical and humoral parameters potentially correlated with BL. Liver and biliary tract ultrasonography was performed with a 3.5 MHz linear probe after at least 12 h of fasting. Results. The prevalence of BL in CRF patients was 22%, which was higher than in the general population (χ2 = 9.4, P < 0.002) but lower than in HD patients (χ2 = 25.9, P < 0.0001). Age was similar in the three groups. Body mass index (BMI) was significantly higher in the CRF group than in both HD patients (P < 0.0001) and the general population (P < 0.0001). When the CRF group was divided into subjects with or without BL, the only difference was lower serum calcium levels in the subgroup with BL (P < 0.04). Conclusions. The prevalence of BL in a Sicilian population of CRF patients was higher than in the general population, but lower than in patients with CRF on chronic HD. Apart from BMI, none of the risk factors traditionally associated with BL in the general population were related to BL in the CRF patients. These data suggest that other factors inherent to kidney pathology contribute to the high prevalence of BL in CRF patients.