Objective: In this case-control study, we sought to determine whether the incidence of gallbladder stones (GBS) was increased in chronic renal failure (CRF) patients on a hemodialysis (HD) program. We also evaluated factors, such as lipid profiles and gallbladder motility, that could affect the formation of GBS. In addition, we reviewed other available studies on this subject and compared the factors that might have some influence on the development of GBS.
Methods: A total of 182 CRF patients (135 male, 47 female, mean age 32.1 yr) undergoing chronic HD and who were referred to our transplantation center in the last 10 yr and 194 healthy controls (137 male, 57 female, mean age 33.3 yr) were included in the study. Abdominal ultrasound was performed on all patients, and ALT, AST, and lipid profiles were determined. In addition, 19 patients with CRF (12 male, 7 female, mean age 33.5 yr) and 22 controls (14 male, 8 female, mean age 33.2 yr) who were age and sex matched were randomly chosen for gallbladder emptying, monitored by ultrasound at 30-min intervals for 2 h after a mixed meal. Fasting volume, minimal residual volume, and ejection fraction of the gallbladder were assessed. For statistical analysis, chi(2), t test, and logistic regression analysis were used.
Results: GBS were detected in seven patients with CRF (3.85%, 5 male, 2 female) and three controls (1.55%, one male, two female) (p > 0.05). The mean follow-up time of CRF patients after diagnosis was 39.3 months (range: 2-168), the mean duration of HD was 21.8 months (range: 1-120). The analysis of seven stones in the CRF group revealed that five were cholesterol-rich stones, and two were mixed (cholesterol and bilirubin) stones. Cholesterol levels were higher in the control group, and triglycerides were higher in the CRF group, but these findings were nonsignificant (p > 0.05). Other biochemical values were not significantly different between the groups. CRF patients with and without GBS were similar in their duration of CRF and HD, age, and other biochemical parameters (p > 0.05). When gallbladder emptying was considered, there was no difference between the two groups in fasting volume, residual volume, and ejection fraction (CRF: 89.7%; controls: 92.3%) of the gallbladders (p > 0.05).
Conclusions: We detected similar incidences of GBS in CRF patients undergoing HD and healthy controls, and this was comparable to the results of most of the previous studies. Young male CRF patients had a nonsignificantly higher incidence of GBS than control males. Although cholesterol-rich GBS were predominant, we could not find any significant difference between the groups when factors that could affect GBS formation, such as lipid profiles and gallbladder motility, were taken into account.