Biliary cholesterol saturation in non-obese women and non-obese men before and after puberty.

The lipid composition of gallbladder bile was determined in forty-seven normal, non-obese subjects (twenty females and twenty-seven males) without gallstones ranging in age from seven months to twenty-nine years. Before puberty, bile was undersaturated with cholesterol in both sexes to the same extent. After puberty a marked increase in cholesterol saturation was observed in females but not in males (138% vs 88%; P less than 0.01). A significant correlation between age and cholesterol saturation could be observed in females (r = 0.546; P less than 0.05) but not in males. In addition a significant correlation between absolute weight and cholesterol saturation in all females (r = 0.827; P less than 0.001) and those after puberty (r = 0.659; P less than 0.05) could be demonstrated. In neither sex was saturation related to body mass index or ideal body weight. These findings suggest that saturation of bile raises in women during puberty but not in men, and this sex-related difference in cholesterol saturation probably contributes to the more common occurrence of gallstones in women than in men.