Effect of two kinds of different combined oral contraceptives use on bone mineral density in adolescent women.

Steroid hormonal contraceptives are highly effective and widely used. Most studies have shown a negative effect of combined oral contraceptives (COCs) on the bone mineral density (BMD) of adolescents. The study was conducted to compare BMD among users of ethinylestradiol/desogestrel, users of ethinylestradiol/cyproterone acetate and nonhormonal control subjects in women aged 16-18 years. The study included 450 women 16-18 years of age. One hundred fifty women were using ethinylestradiol/desogestrel, 150 women were using ethinylestradiol/cyproterone acetate, and 150 women were using nonhormonal contraception as control subjects. BMD ofthe lumbar spine and femoral neck was obtained using dual-energy X-ray absorptiometry, and mean BMD changes in COCs users and nonusers were compared. At 24 months of treatment, lumbar spine and femoral neck mean BMD values in women (n=127) who used ethinylestradiol/desogestrel were slightly lower compared with baseline, but these effects did not reach statistical significance (p=.837 and p=.630, respectively). The mean lumbar spine and femoral neck BMD values in women (n=134) who used ethinylestradiol/cyproterone acetate were slightly higher compared with baseline, but there was no statistical significance (p=.789 and p=.756, respectively). The increases in mean percent change in lumbar spine and femoral neck BMD in the ethinylestradiol/cyproterone acetate group were less than those in the control group (1.88% vs. 0.30% and 0.98% vs. 0.49%, respectively). There were no significant differences in mean BMD of the lumbar spine and femoral neck between the users of ethinylestradiol/desogestrel or ethinylestradiol/cyproterone acetate and nonusers (p>.05). Our study indicates that 2 years of COCs therapy had no significant effect on bone density in adolescents, but it remains unknown whether therapy longer than 2 years has a significant adverse effect on the attainment of peak bone mass.