Association between common bile duct stones and treated hypothyroidism

BACKGROUND/AIMS: The purpose of this study was to investigate the frequency of diagnosed hypothyroidism in patients with common bile duct stones. METHODOLOGY: The common bile duct stone group (Group I) consisted of all the patients who had verified gallstones in the common bile duct in endoscopic retrograde cholangiopancreatography during 1995. The control group (Group II) was matched for age, sex, and hospital admission. These patients did not have diagnosed gallbladder or common duct stones. In both groups there were 86 patients (56 women and 30 men). The median age in these groups was 73 (range: 22-92) years at the time of common bile duct stone diagnosis. Medical records of all patients were reviewed. RESULTS: In Group I the prevalence of previously diagnosed hypothyroidism was 7/86 (8%) compared with 1/86 (1%) in Group II (P = 0.01). Hypothyroidism was previously diagnosed only in the common bile duct stone patients (Group I) of over 60 years of age, where the prevalence was 7/66 (11%). In addition, we studied 36 consecutive gallbladder stone patients (Group III) of over 60 years, who had no evidence of common bile duct stones. Hypothyroidism had been diagnosed in them less frequently (2/36 = 6%) than in the age and hospital admission matched common bile duct stone patients (P = 0.01). Other diagnosed endocrine disorders did not differ between the study groups. CONCLUSIONS: There is a significant association between the common bile duct stones and previously diagnosed hypothyroidism. There stronger association between the common bile duct stones and hypothyroidism compared to gallbladder stones and hypothyroidism suggests a mechanism other than merely the cholesterol metabolism mediated mechanism. The 11% prevalence of previously diagnosed hypothyroidism in the common bile duct stone patients of over 60 years of age suggests all patients with common bile duct stones be screened for current thyroid dysfunction.