Abstract and Introduction
Abstract
Objective: The aim of this study was to examine the association between fracture and pelvic organ prolapse (POP) in postmenopausal women enrolled in the Women's Health Initiative Estrogen Plus Progestin trial.
Methods: POP was assessed as cystocele, rectocele, or uterine prolapse and was graded as either "absent to mild" or "moderate to severe." Cox proportional hazard analyses (adjusting for age, body mass index, race, asthma, emphysema, thyroid disease, family history of fracture, regular menses, age at menopause, nulliparity, history of hormone therapy [HT], history of falls, socioeconomic status, calcium, and vitamin D supplementation and physical activity) explored the relationships between moderate to severe POP and incident bone fractures.
Results: Moderate- to severe-grade POP was identified in almost 8% of women (n = 1,192). During a follow-up duration of 7.41 (2.18) years (mean [SD]), 2,156 incident fractures were observed; the most common fracture site was the lower arm (n = 615; 28.51%) followed by the hip (n = 205; 9.51%). Adjusted analyses confirmed moderate to severe POP (of any type) as an independent risk factor for incident hip fractures (hazard ratio [HR], 1.83; 95% CI, 1.16–2.89; P = 0.010). On analyses stratified by assigned treatment (HT vs placebo), moderate to severe rectocele emerged as an independent predictor of incident spine (HR, 2.61; 95% CI, 1.04–6.56; P = 0.042) and lower arm fractures (HR, 1.87; 95% CI, 1.06–3.29; P = 0.030) in the placebo group.
Conclusions: We identify moderate to severe POP (any type) in postmenopausal women as a risk factor for hip fracture; moderate to severe rectocele holds an additional risk of spine and lower arm fractures in women not taking HT.
Introduction
Pelvic organ prolapse (POP) is a recognized contributor to morbidity in an aging female population and to the overall healthcare cost in the community. More than 300,000 surgical procedures are reportedly performed annually for POP in the United States, with an incurred cost in excess of $1 billion. The prevalence of POP attests to the magnitude of its potential healthcare burden. As many as 41% of postmenopausal (PM) women enrolled in the Women's Health Initiative Estrogen Plus Progestin (WHI-EP) trial demonstrated some degree of POP.
Both qualitative and quantitative deficiencies in pelvic collagen are believed to exist in women with POP. Conversely, a predisposition to POP is identified in women with generalized connective tissue disorders. The role of skeletal collagen in conferring architectural tissue strength is underscored by an increased incidence of fractures in collagen disorders like Marfan and Ehlers-Danlos syndromes. Limited data are suggestive of global collagen deficiency in women with evidence of POP. Pursuing a hypothesis that PM women with evidence of POP may be at an enhanced lifetime risk for skeletal fragility, we previously identified an association between moderate to severe POP and compromised skeletal integrity in the PM population. Analyses of baseline data from the WHI-EP trial revealed a higher prevalence of low bone mineral density (BMD) and an enhanced likelihood for fractures (after age 55 y) in PM women identified with moderate to severe POP compared with those with absent to mild POP, thus expanding the spectrum of health concerns associated with POP.
Extending our earlier observations, we herein demonstrate that PM women with moderate to severe POP are significantly more likely to experience incident fractures compared with those with absent to mild POP. The current study was undertaken using the longitudinal data on PM women recruited in the WHI-EP Trial, details of which have previously been published.