Bone mineral density in women with polycystic ovary syndrome

Abstract

Purpose: PCOS is a complex disorder and various features of this disorder may have great importance for bone metabolism. The aim of the study was to determine the relationship between existing hormonal disorders, and bone mineral density (BMD) in young women with PCOS.

Methods: 69 reproductive-aged PCOS women and 30 age-matched healthy controls were enrolled to the study women. In each individual we assessed the body mass index (BMI). We evaluated the serum concentrations of: gonadotropins, prolactin (PRL), estradiol (E2), dehydroepiandrosterone sulfate (DHEAS), testosterone (T), thyroid stimulating hormone (TSH), free thyroxine (fT4). We used the Homeostatic Model Assessment-Insulin Resistance Index (HOMA-IR) to diagnose insulin resistance. Bone mineral density in the lumbar spine was measured by dual-energy X-ray absorptiometry (DXA).

Results: The PCOS women had lower BMD values as compared to the controls (1.057 ± 0.1260 vs. 1.210 ± 0.1805 g/cm(2), p < 0.0002). In the analysis of PCOS patients according to BMI, only in the subgroup of the normal weight PCOS we find significantly lower BMD in comparison to controls (p = 0.0049). In patients with PCOS, BMD was positively correlated with insulin concentration and HOMA-IR. In the controls Z-score values were positively correlated with insulin concentration and HOMA-IR.

Conclusions: The deleterious effect of estrogen deficiency on bones in PCOS is not balanced by androgen overproduction. Women with PCOS had significantly lower BMD of the lumbar spine compared to controls. Insulin seems to be one of the most important positive bone growth stimulators.

Fig. 1

The correlation between BMD and serum insulin concentrations in PCOS patients (r = 0.25, p = 0.0347). BMD bone mineral density, Ins Insulin