Pelvic floor disorder symptoms and bone strength in postmenopausal women

Introduction and hypothesis: The current study is aimed at characterizing the association between pelvic floor disorder symptoms and bone strength reflecting a potential connective tissue pathophysiology in postmenopausal women.

Methods: A cross-sectional study was conducted in postmenopausal women undergoing osteoporosis evaluation from 2007 to 2010. Urinary incontinence (UI) was defined as urinary leakage ≥2-3 times/week. UI types were defined using the 3 Incontinence Questionnaire. Fecal incontinence was defined as stool leakage ≥1/month, and pelvic organ prolapse as a positive response to "Do you have a bulge or something falling out that you can see or feel in your vaginal area?" Bone quality and quantity were assessed using the trabecular bone score (TBS) and bone mineral density respectively: bone strength was defined by combined quality/quantity index, low strength being equivalent to moderate to severe fracture risk; low quality as TBS ≤ 1.31; low quantity by T-score <-1 or on osteoporosis medication.

Results: Of 681 subjects, 262 had low bone strength whereas 419 were normal using the combined quality/quantity bone assessment. Characteristics were similar except for age (low bone strength: 69.0 ± 8.2 vs normal: 65.0 ± 7.1, p < 0.01) and smoking (8.8% vs 3.3%, p < 0.01). Low bone strength was associated with any UI (adjusted odds ratio [aOR]: 1.48, 1.05-2.10), stress (aOR: 1.53, 1.06-2.21), and mixed (aOR :1.45, 1.02-2.05). Women with low bone quality had increased odds of UI (any, urgency, mixed), whereas none of the pelvic floor disorder symptoms was associated with low bone quantity.

Conclusions: Low bone strength defined by a combined quantity/quality index, as well as low bone quality alone, were associated with increased risk of UI.