Serum concentrations of markers of type I collagen metabolism in women taking monophasic oral contraceptives.

Objectives: To investigate serum concentrations of the carboxy-terminal propeptide of type I procollagen (PICP) and cross-linked carboxy-terminal telopeptide of type I collagen (ICTP), reflecting the rate of synthesis and degradation of the parent collagen respectively, in women using monophasic oral contraceptives.

Study Design: PICP and ICTP were estimated in 60 women taking 20 micrograms of ethinyl estradiol (EE) + 150 micrograms of desogestrel (DSG) or 30 micrograms of EE + 150 micrograms DSG over six months.

Results: Mean PICP concentration decreased in women receiving 20 micrograms of EE + 150 infinity g of DSG after three cycles of administration. However, after six months this value returned to a level comparable to the initial one. In women taking 30 micrograms of EE + 150 micrograms of DSG the mean concentrations of PICP did not change significantly throughout the period studied. None of the oral contraceptives noticeably influenced the concentrations of ICTP.

Conclusion: Investigated oral contraceptives do not significantly affect the metabolism of type I collagen, however a transient decrease in its biosynthesis may be expected during the use of formulations containing 20 micrograms of EE.