Elevated serum androstenedione is associated with a more severe phenotype in women with polycystic ovary syndrome (PCOS).

Objective: To evaluate the impact of elevated serum Δ4A levels on the hormonal and metabolic features of the different phenotypes of PCOS.

Methods: 1276 women with PCOS according to the Rotterdam criteria were included, in whom serum hormonal levels were determined.

Results: In PCOS women as a whole, as well as in patients presenting clinical and/or biochemical hyperandrogenemia (phenotypes I and II), Δ4A levels >3.8 ng/ml were positively related to LH, LH/FSH ratio, T, DHEAS, 17 OH progesterone and FAI and negatively related to T/Δ4A ratio. In the milder phenotype III, a positive correlation between Δ4A levels >3.8 ng/ml and T, DHEAS, 17 OH progesterone and FAI and a negative one between increased Δ4A and T/Δ4A ratio were reported. In the whole PCOS group with androstenedione >3.8 ng/ml, an increased ovarian volume was observed, while a greater mean follicular number was found only in phenotypes I and II.

Conclusions: Increased serum Δ4A levels, which are associated with more severe PCOS phenotypes, possibly contribute to the worsening of PCOS features and therefore could be a valuable marker of biochemical hyperandrogenemia.