Prevalence of Back Pain in Postmenopausal Osteoporosis and Associations with Multiple Spinal Factors

Abstract

Back pain is considered to be most prevalent musculoskeletal pain, particularly in elderly populations (Woo et al., 2009). The existing literature suggests a prevalence of chronic back pain among the elderly ranging from 7% to 58% (Edmond & Felson, 2000; Jacobs et al., 2006; Lavsky-Shulan et al., 1985; March et al., 1998), with differences attributable to a lack of concordance in terms of age stratification, definition, and methodology, but with consistently much higher rates in women than men (Jabobs et al., 2006; Woo et al., 2009). The reason why back pain is common among elderly women may be related to osteoporosis. As lower bone mineral density (BMD) and the rapid decline in BMD following menopause in women result in a greater prevalence of osteoporosis and vertebral fractures compared to men, osteoporosis is likely to represent a major cause of back pain among elderly women. However, although osteoporosis may be an underlying cause of back pain, especially in postmenopausal elderly women, the prevalence of back pain in this group has not been fully investigated. Although back pain in osteoporosis is often attributed to vertebral fractures (Nevitt et al., 1998; Ulivieri, 2007), the intensity of pain is not always influenced by fracture status (Hubscher et al., 2010). Liu-Ambrose et al. demonstrated that osteoporotic women may experience back pain without a concomitant history of vertebral compression fractures (LiuAmbrose et al., 2002). The cause of back pain in osteoporosis thus seems likely to be related to multiple factors. Spinal alignment and mobility are important factors for spinal function and may be related to back pain. Loss of lumbar lordosis correlates well with the incidence of chronic low back pain in adults (Djurasovic & Glassman, 2007; Glassman et al., 2005). Patients with a less mobile spine may show more severe symptoms. In addition, we have previously demonstrated that back extensor strength is significantly associated with spinal mobility (Miyakoshi et al., 2005). However, to the best of our knowledge, simultaneous assessment of back pain and multiple spinal factors such as vertebral fractures, spinal alignment and mobility, as well as back extensor strength, has not yet been investigated in patients with osteoporosis. The objectives of this study were thus: 1) to determine the prevalence of back pain in patients with postmenopausal osteoporosis who visited their practitioner; and 2) to evaluate