Background: High biliary calcium and trace elements (copper, zinc and iron) in patients with chronic cholelithiasis can be associated with gallstones.
Methods: Estimations of calcium, copper, zinc and iron were done in the serum, gall bladder bile and gallstones of 48 patients with chronic cholelithiasis and in 20 age- and sex-matched controls. Biliary levels of calcium and trace elements and bile/serum ratio of calcium and trace elements were compared in the two groups.
Results: Serum calcium was significantly less (P = 0.009) than controls, but biliary calcium was higher in the patients with chronic cholecystitis. All trace elements were found to be significantly higher (P </= 0.036) in the bile of patients with chronic cholelithiasis. The bile/serum ratio of calcium, copper and zinc was significantly greater (P </= 0.03) in patients of chronic cholelithiasis. Gall bladder bile in patients with chronic cholelithiasis was slightly more alkaline. Pigment stones contained significantly more calcium, copper and iron than cholesterol stones (P </= 0.001).
Conclusion: Higher biliary calcium and trace elements as well as a defective pH of gall bladder bile in patients with chronic cholelithiasis could be the underlying factor in the pathogenesis of gallstones.