Association of pelvic organ prolapse and fractures in postmenopausal women: analysis of baseline data from the Women's Health Initiative Estrogen Plus Progestin trial.

OBJECTIVE: Testing a hypothesis that pelvic organ prolapse (POP) is a focal manifestation of disordered connective tissue, we evaluated whether there is an association between POP and history of fracture.
DESIGN: This was a case-control study. Baseline data were from postmenopausal women aged 60 years or older enrolled in the Women's Health Initiative Estrogen Plus Progestin trial. Distinct variants (cystocele, rectocele, and uterovaginal) and severity (mild, moderate, or severe) of POP were recognized. A history of "fracture after age 55" was considered as the event of interest.
RESULTS: Moderate to severe POP was identified in 9% of 11,096 participants aged 60 years or older. Women with moderate to severe rectocele were significantly more likely to report fracture (odds ratio: 1.37, 95% CI: 1.06-1.77, P = 0.02) compared with those with absent to mild prolapse. Of the subset of participants who underwent bone mineral density assessment, those with moderate to severe prolapse demonstrated significantly lower whole-body bone mineral density ([beta] = -0.03, SE 0.02); this difference was of borderline significance (P = 0.05) compared with that for participants with absent to mild POP. Multivariate logistic regression analysis confirmed an independent association between moderate to severe rectocele and fracture (odds ratio: 1.45, 95% CI: 1.08-1.95, P = 0.01).
CONCLUSIONS: We demonstrate a relationship between moderate to severe POP and low bone mineral density in postmenopausal women enrolled in the Women's Health Initiative Estrogen Plus Progestin trial. Our findings of an association between clinically significant (moderate to severe) POP, specifically rectocele, and a history of fracture suggest that suboptimal collagen status purported to associate with POP may also involve bone collagen and hence translate into skeletal compromise.