Does chronic oral contraceptive use detrimentally affect C‐reactive protein or iron status for endurance‐trained women?

PURPOSE: Chronic use of the oral contraceptive pill (OCP) is reported to increase C‐reactive protein (CRP) levels and increase the risk of cardiovascular disease in premenopausal females. METHODS: A secondary analysis of data from two research studies in eumenorrheic (n = 8) and OCP (n = 8) female athletes. Basal CRP and iron parameters were included in the analysis. Sample collection occurred following a standardized exercise and nutritional control for 24 h. Eumenorrheic females were tested in the early‐follicular and mid‐luteal phases, and the OCP users were tested in quasi‐follicular and quasi‐luteal phases (both active pill periods). RESULTS: A main effect for group (p < 0.01) indicated that average CRP concentration was higher in OCP users compared with eumenorrheic females, regardless of the day of measurement within the cycle. Results demonstrate a degree of iron parameters moderation throughout the menstrual cycle that is influenced by basal CRP levels; however, no linear relationship with CRP, serum iron, and ferritin was observed. CONCLUSIONS: Basal CRP values were consistently higher in the OCP group despite participants being in a rested state. These results may indicate a potential risk of cardiovascular disease in prolonged users of the OCP when compared to eumenorrheic female athletes.