Bone health and prevalent fractures in women with polycystic ovary syndrome: a meta-analysis and endocrine-context pathophysiology review

Bone health in those with Polycystic Ovary Syndrome (PCOS) is complex, but the general consensus is that cortical areal bone mineral density (aBMD) sites will be higher in PCOS than in age- and BMI-similar controls. However, spine aBMD sites may be lower, especially in non-obese PCOS. Whether or not incident fracture risk is increased in PCOS is currently controversial; no meta-analysis has yet assessed prevalent fractures.

We assessed the bone effects of PCOS-related ovarian hormone alterations, e.g. androgen excess, tonically normal/higher estradiol, and lower-than-normal progesterone levels. We also highlighted evidence that common PCOS medications (e.g. combined hormonal contraceptives [CHC], metformin, and spironolactone) have important bone effects. In adolescents, meta-analysis of CHC showed significant negative aBMD changes. Inflammation has negative PCOS bone effects and is linked with CHC use.

Is fracture risk altered by PCOS? Our meta-analysis showed a 25% increased risk of prevalent fracture in PCOS versus controls; this did not reach statistical significance. Future prospective research needs to collect and evaluate ovulation characteristics, progesterone exposure, and adolescent CHC use, in addition to the complex variables that may influence risks for prevalent or incident fragility fractures and/or for cortical and cancellous aBMD values in PCOS.