The pill's effect on lipid levels.

The Pill's effect on lipid levels

Lifestyles changes, such as stopping smoking or changing diet, may help prevent coronary artery disease, but some women on the Pill should add another change to the list, according to a report in the January OBSTETRICS AND GYNECOLOGY.

women using oral contraceptives should take those that minimize the hormone progestin's adverse effects on blood lipid levels, which are associated with coronary artery disease, says the study's principal author, Ronald T. Burkman, head of gynecology and obstetrics at Detroit's Henry Ford Hospital.

"Stopping smoking or changing diet is not easy, but changing the Pill you take can be done", says Burkman. Specifically, he says, different types of progestin, with varying effects on blood lipid levels, are found among today's oral contraceptives. As for the hormone estrogen, which helps to counter progestin's adverse effects, most contraceptives contain the same type.

"This (advice) is for preventing heart disease down the road because the actual risk for coronary artery disease is very rare among current users. It mainly occurs among older, smoking women," says Burkman, who was at Johns Hopkins University in Baltimore when the study was done.

Previous studies of higher-dose oral contraceptives-those containing high levels of both estrogen and progestin-have similarly shown varying effects on blood lipid levels, depending on the type of progestin used. But Burkman's is among the first prospective studies to examine the lower-dose oral contraceptives that are now available, says Robert H. Knopp, director of the Northwest Lipid Research Clinic at the University of Washington in Seattle.

In the study, Burkman and his colleagues randomly divided 266 women into four groups. The four groups were given oral contraceptives with different progestin preparations. In all the groups, total cholesterol levels increased 5.9 to 9.1 percent after six months, and low-density lipoprotein cholesterol, which is the type that increases the risk of heart disease, increased 10 to 15.6 percent. But the differences from group to group were not significant.

Group differences were noticed, however, in levels of the "good" high-density lipoprotein (HDL) cholesterol and apolipoprotein A-1, both of which are believed to help reduce the risk of coronary artery disease.

The group taking a Pill with the progestin ethynodiol diacetate showed the only increase in HDL cholesterol and the largest increase in apolipoprotein A-1 levels, while the group taking a Pill with levonorgestrel showed the largest decrease in HDL cholesterol and the smallest increase in apolipoprotein A-1 levels. It is not understood why these specific progestins have these different effects, Burkman says.

The two other preparations studied, which contained different amounts of norethindrone, fell in the middle for the HDL cholesterol and apolipoprotein A-1 levels.