Short-term effects of an oral contraceptive containing oestradiol valerate and dienogest on bone metabolism and bone mineral density: an observational, preliminary study.

Objectives: To evaluate the effects of a combined oral contraceptive (COC) containing dienogest/oestradiol valerate (DNG/E2V) on bone mineral density (BMD) and on serum and urinary bone turnover markers in young, healthy, fertile women.
Methods: At baseline and after three and six months of intake of the aforementioned COC, serum and urinary calcium, osteocalcin, urinary pyridinoline (PYD), and deoxypyridinoline (D-PYD) of 30 women aged 21 to 34 years were measured. At baseline and after six months, lumbar bone mineral density was determined by dual-energy X-ray absorptiometry (DEXA).
Results: Urinary levels of PYD and D-PYD were significantly lower at three and six months in comparison with basal values (p < 0.05). Serum calcium levels showed an increasing trend, which reached statistical significance after six months in comparison with basal values while urinary levels of calcium did not vary significantly. Serum osteocalcin levels were somewhat, but not significantly, lower during pill use in comparison with basal values. After six months, spinal BMD values did not differ significantly from basal values.
Conclusions: The DNG/E2V COC has no short-term adverse effect on bone turnover markers. No significant change in BMD was observed after six months of use of that pill.