Ferritin Levels in Women with PCOS.

Objective: To study ferritin levels, and potential factors influencing them, in women with polycystic ovary syndrome (PCOS), and to investigate potential associations between ferritin levels and other parameters in these women.

Design: Longitudinal general population -based cohort study, including data from both questionnaires and clinical measurements.

Subjects: The study was conducted with data from the participants of the Women's Health Study, including a total of 1918 Finnish women, around 35 years of age.

Exposure: PCOS was defined according to the Rotterdam criteria by the presence of at least two of the following findings: oligo/amenorrhea, hyperandrogenism (clinical or biochemical), and polycystic ovarian morphology.

Main outcome measures: Serum ferritin levels and other parameters were determined from the cohort data and the associations between ferritin levels and other investigated parameters were investigated with linear regression models.

Results: Women with PCOS had significantly higher median ferritin levels than women without PCOS (51.43 μg/L vs 44.85 μg/L, p=0.020). Low ferritin levels were less common among women with PCOS who had oligo- or amenorrhea than in those who did not (1.5% vs 11.8%, p=0.024). Median ferritin levels were also found to be lower in hyperandrogenic women with PCOS than in those with normoandrogenemia (49.96 μg/L vs 73.50 μg/L, p=0.011). Women with PCOS had higher fasting insulin levels than women without PCOS (8.85 mU/L vs 7.60 mU/L), and a positive association between fasting insulin and ferritin levels was found in the whole population (effect size: 0.0619, 95% confidence intervals: 0.005; 0.119, p=0.034). Finally, associations between ferritin levels and history of infertility were investigated in both the total population and in women with PCOS, but no significant associations were found.

Conclusion: Our results suggest that women with PCOS have higher ferritin levels than those without PCOS, and that both the decreased blood loss from irregular menstruation and elevated androgen levels can influence ferritin levels in women with PCOS. A metabolic connection was also found as serum insulin levels associated positively with serum ferritin levels in the total population, whereas history of infertility did not seem to associate with serum ferritin levels in any of the study groups.