54 Usha Verma and Neil Verma
such as the 19-norprogesterones, do not exert any androgenic effect and
therefore have no negative effect on the lipids. 19-nortestosterone derivatives
and even some 17-hydroxyprogesterones have a partial androgenic effect, and
hence exert a negative effect on surrogate markers of cardiovascular risk.
Estrogen has an antiatherogenic effect and this beneficial effect of estrogen is
not reversed by the progesterone. Estrogen also preserves the normal
endothelium-mediated dilation of coronary arteries, and Progesterone does not
reverse this cardioprotective mechanism. Not all progestins have a similar
effect on the cardiovascular system. Progestins, such as medroxyprogesterone
or norethisterone acetate, exert a partial negative effect on the beneficial
actions of estrogens with regard to lipid changes, atheroma development or
vasomotion. In contrast, progesterone itself does not have this inhibitory effect
on lipid changes and vascular reactivity. Nonandrogenic molecules of
progesterone itself and of derivatives such as 19-norprogesterones have a
neutral effect on the vessels 121].
Effect on Lipoproteins: Studies in pre-menopausal women using OCPs
have shown a dose-related response in the lipid profile. Women using a 20-μg
Ethinyl estradiol (EE)/100-μg LNG OCP demonstrated reductions in high-
density lipoprotein cholesterol (HDL-C) and small increases in low-density
lipoprotein cholesterol (LDL-C) and triglycerides (TG), in contrast to a 30-μg
EE/150-μg LNG OCP [122]. The amount of lipid alteration also depends on
the delivery route, where transdermal contraceptive hormone delivery is
relatively less potent compared with oral [123]. Barkfeldt et al. [124]
conducted a randomized, double-blind study that evaluated the effects of lipid
metabolism on 98 women who received 2 different types of progestin-only
pills, desogestrel 75 μg/day or LNG 30 μg/day. There were minimal changes
seen in the lipid profile except for decreasing trends with levels of HDL-C, its
subfractions, and the apolipoproteins apolipoprotein-I and -II. No differences
were observed between the 2 formulations despite the higher progestin dose
found in desogestrel, including no changes in LDL-C or apolipoprotein-B
[124].
Blood pressure: Most studies have shown an increase in blood pressure in
normotensive women with OCP use [125]. A review of 2 studies found an
increase in systolic blood pressure by 7 to 8 mm Hg on average compared with
systolic blood pressure in those not using OCP [126, 127]. Different
progesterones have a different effect on blood pressure. In a study of 120
women randomized to drospirenone/EE or LNG/EE, the drospirenone group
demonstrated a mean decrease in the systolic blood pressure (from 107.4 to
103.5 mm Hg) and had a statistically significant lower mean blood pressure