CLINICAL CORRELATES OF GALLSTONE COMPOSITION - DISTINGUISHING PIGMENTFROM CHOLESTEROL STONES

Objectives: The prevalence of cholelithiasis has been established in p opulation-based surveys employing ultrasonography, and major risk fact ors have been identified, However, the clinical and epidemiological fe atures that distinguish patients with pigment gallstones from those wi th cholesterol stones have received little attention, Methods: We pros pectively surveyed 551 patients undergoing cholecystectomy for gallsto nes at two teaching hospitals. Clinical and epidemiological data were collected during patient interviews and by chart review. Gallstones we re collected at surgery; physical measurements were recorded, and ston e composition was determined by visual inspection and infrared spectro scopy. Results: Patients with pigment stones were older than patients with cholesterol stones (p < 0.00001). Almost all patients under age 4 0 yr old had cholesterol stones, but most patients over 70 had pigment stones. Cirrhosis was strongly associated with pigment gallstones (p < 0.00001), although alcohol consumption was unrelated, Univariate ana lyses suggested associations of stone composition with male sex, diabe tes mellitus, educational attainment, and use of thiazides or oral con traceptives, but these were not significant in a logistic regression t hat adjusted for age, cirrhosis, and other variables. Patients with pi gment cholelithiasis had stones that were generally smaller in diamete r and fewer in number than those with cholesterol stones, Conclusions: Compared to patients with cholesterol gallstones, those with pigment stones are older and more likely to have a diagnosis of cirrhosis. In addition, their stones are smaller in size and fewer in number than th ose from patients with cholesterol cholelithiasis.