Effect of synthetic oestrogens and progestagens in oral contraceptives on bile lipid composition
Down, R.H.; Whiting, M.J.; Watts, J.M.; Jones, W.
Gut 24(3): 253-259
1983
ISSN/ISBN: 0017-5749 PMID: 6826111 DOI: 10.1136/gut.24.3.253Document Number: 420244
The prevalence of cholesterol gallstones in young women has increased since the introduction of oral contraceptives. The synthetic female sex hormones used in these preparations, increased the degree of cholesterol saturation in bile. To determine whether estrogens, progestagens or both, are responsible for the change in biliary cholesterol saturation index, a prospective randomized, controlled study was performed. A significant increase in the cholesterol saturation index of bile was observed when either 30 .mu.g ethynylestradiol plus 150 .mu.g norgestrel (P = 0.01) or 50 .mu.g ethynylestradiol plus 250 .mu.g norgestrel (P < 0.01) were ingested daily for 2 mo. No change in the cholesterol saturation index was observed when 30 .mu.g ethynylestradiol alone or 30 .mu.g ethynylestradiol plus 2.5 mg norethisterone were used. The mechanism for the increase in cholesterol saturation index did not appear to involve bile acid metabolism. The progestagen, norgestrel and not as previously thought the estrogen, ethynylestradiol, is responsible for the increase in cholesterol saturation of bile which accompanies the use of oral contraceptives.