Effects of oral contraceptives on the gallbladder bile of normal women.

In view of the reported association between use of oral contraceptives and gallbladder disease, the effects of contraceptive steroids on the lipid composition of gallbladder bile were studied in 22 healthy women. Each subject was studied during routine use of oral contraceptives and also during normal menstrual cycles on no medication. Gallbladder bile was significantly more saturated with cholesterol during contraceptive therapy than during normal menstrual cycling (125 versus 92 per cent, P less than 0.001). Chenodeoxycholic acid accounted for a significantly smaller proportion (35 versus 42 per cent P less than 0.001) and cholic acid a significantly greater proportion (50 versus 41 per cent (P less than 0.001) of total bile acids during contraceptive steroid therapy. These findings show that exogenous sex steroids in doses and formulations routinely prescribed induce important alterations in the composition of human gallbladder bile, and suggest a biochemical basis for the increase in gallbladder disease observed among women using oral contraceptives.