Competing Factors Link to Bone Health in Polycystic Ovary Syndrome: Chronic Low-Grade Inflammation Takes a Toll

Abstract

Chronic inflammation predisposes to poor bone health. Women with polycystic ovary syndrome (PCOS) experience androgen excess, ovulatory disturbances, insulin resistance, abdominal adiposity and chronic inflammation. Our objective was to investigate the relationships among bone health parameters, chronic subclinical inflammation and anthropometric measures in premenopausal women with and without PCOS. In 61 premenopausal women, 22 women with PCOS and 39 controls, we assessed bone parameters (total hip bone mineral density [BMD] by dual-energy X-ray absorptiometry and radius strength-strain index [SSI] by peripheral quantitative computed tomography), inflammation (C-reactive protein/albumin), oxidative stress (leukocyte telomere length, urinary 8-hydroxydeoxyguanosine); hemoglobin A1c; anthropometric measures (body mass index, waist-to-height ratio, cross-sectional muscle area). A diagnosis of PCOS negatively predicted (beta = -0.251, p = 0.022) hip BMD in a regression model including weight. In women with PCOS, inflammation, which was predicted by increased waist-to-height ratio and current use of oral contraceptives, attenuated the positive influences of increased weight and muscle mass on bone strength and was inversely associated with radial SSI (R² = 0.25, p = 0.018). In conclusion, chronic subclinical inflammation may negatively impact bone physiology in women with PCOS. Strategies focused on reducing abdominal adiposity and avoiding medications that increase inflammation may counter this effect.

Figure 1

Linear regression of the total hip BMD (g/cm²) with weight (kg) and the radial strength-strain index (SSI, mm³) as the independent variables for women with PCOS (n = 21) and controls without PCOS (n = 39). Weight was a significant predictor of the total hip BMD, R² = 0.72, p < 0.0001 for women with PCOS; R² = 0.29, p < 0.001 for controls. The radial SSI was not a significant predictor of the total hip BMD for the women with PCOS, R² = 0.01, p = 0.68, but was important in the controls, R² = 0.30, p < 0.001.

Figure 2

Linear regression of the radius strength-strain index (SSI, mm³) including weight (kg) and log(CRP/albumin) as an index of inflammation as the independent variables for women with PCOS (n = 22) and controls (n = 39). Weight was not a significant predictor of the radial SSI in women with PCOS, R² = 0.02, p = 0.53, but was important in the controls, R² = 0.19, p = 0.006. Log(CRP/albumin) was predictive of the SSI in women with PCOS, R² = 0.25, p = 0.02, but was not for women without PCOS, R² < 0.01, p = 0.66.