Objective: To evaluate if the levels of the central regulators of osteoclast activity, osteoprotegerin (OPG) and receptor activator for nuclear factor kappaB-ligand (RANk-L), correlate with bone mineral density (BMD) parameters in premenopausal infertile women.
Design: Cross-sectional study.
Setting: Academic infertility practice.
Patient(s): 82 Infertile, but otherwise healthy, premenopausal women< 42 years age presenting for routine care.
Intervention(s): BMD assessment; serum samples (cycle days 1 to 3), questionnaire addressing demographics, medical, social, family, and personal histories.
Main outcome measure(s): BMD categorized as "Low" (Z <or= -1.0) or "Normal" (Z > -1.0); Biomarkers of bone metabolism (BAP, TRAP, NTX, OPG, RANK-L) and ovarian reserve (FSH, estradiol).
Result(s): The prevalence of low BMD was 23% (19/82). Significantly lower levels of OPG were observed in association with low BMD compared with normal BMD (1.37 +/- 0.57 versus 2.0 +/- 1.05 pMol/L). Multivariable logistic regression analyses revealed low OPG levels as independent predictors of low BMD after adjusting for parameters known to influence bone density.
Conclusion(s): We demonstrate an independent relationship between low circulating levels of OPG and low BMD in premenopausal healthy, albeit infertile, women.