Back extensor strength and lumbar spinal mobility are predictors of quality of life in patients with postmenopausal osteoporosis

Summary: To assess the effect of multiple factors on quality of life (QOL) in osteoporosis, relationships between the QOL and possible spinal factors were analyzed in 174 postmenopausal women with osteoporosis. Back extensor strength and lumbar spinal mobility were the most important factors for QOL in these patients. Introduction: Quality of life (QOL) in patients with osteoporosis and vertebral fractures is impaired by the decline of total spinal mobility, although it is not clear to what extent. This study aimed to assess the effect of multiple factors on QOL in patients with osteoporosis. Methods: QOL of 174 postmenopausal women with osteoporosis (mean, 68 years old) was evaluated using the Japanese Osteoporosis QOL Questionnaire (JOQOL). Correlations between the JOQOL score, bone mineral density (BMD) of the lumbar spine/proximal femur/whole body, the kyphosis angle and mobility of thoracic and lumbar spine, the number of vertebral fractures, grip strengths of dominant and non-dominant hands, and isometric back extensor strength (BES) were analyzed. Results: JOQOL showed significant correlation (p<0.05) with age (r=-0.303), BES (r=0.455), dominant and non-dominant grip strengths (r=0.273 and r=0.255, respectively), number of vertebral fractures (r=-0.282), BMDs of proximal femur and whole body (r=0.200 and r=0.157, respectively), lumbar kyphosis angle (r=-0.296), and lumbar spinal mobility (r=0.345). Multiple regression analysis revealed that the BES and lumbar spinal mobility were the significant contributors to the JOQOL (p<0.05). Conclusion: BES and lumbar spinal mobility are the important factors for QOL in patients with postmenopausal osteoporosis.