Cross sectional and prospective observational study in Japanese postmenopausal women.
The aim of the study was 2-fold. The first was to investigate what kind of comorbidities could be found in conjunction with back pain in Japanese postmenopausal women. The second was to investigate whether significant relationship between baseline back pain and future fracture exists or not.
Back pain has been reported to be associated with vertebral degeneration or vertebral fracture. However, there has been no available data that indicates the relationship between back pain and future fracture risks.
The subjects who visited their practitioner were examined for their prevalent back pain or pains in other site. Bone mineral density, body height, body weight, and serum parameter were measured at baseline, and comorbidities were investigated by interview. Fragility fractures were also assessed at baseline and then followed up with 1- to 2-year intervals. The correlation between back pain and baseline characteristics was investigated by logistic regression analysis. The hazard ratio of back pain to future vertebral fracture was estimated by multivariate Cox regression analysis.
A total of 899 postmenopausal ambulatory women (62.5 ± 10.3 years old) were enrolled and 81 subjects were dropped out from the study within 1 year. The remaining 818 postmenopausal women (62.1 ± 10.3 years) were followed-up for 5.7 ± 3.5 years. Compared to the group without pain, the group with back pain had significantly higher age, lower bone mineral densities at lumbar spine and hip, and higher number of prevalent vertebral fractures. The back pain was significantly associated with rheumatic arthritis (odds ratio [OR]: 2.01, P < 0.05), prevalent vertebral fracture (OR: 4.60, P < 0.001) and osteoporosis (OR: 2.14, P < 0.001). A total of 189 future fractures were observed, of which the most frequent was vertebral fractures (78.3%). The fact that baseline back pain was a significant risk factor for time-dependent vertebral fractures (hazard ratio: 1.62, 95% confidence interval: 1.16–2.27, P = 0.005) was demonstrated by the Cox hazards model after adjusting for traditional risk factors, such as age, bone mineral density, and prevalence of vertebral fractures.
The data obtained in this study indicated that the back pain is significantly associated with osteoporosis and rheumatoid arthritis and that it can be useful predictor for future vertebral fracture risk in Japanese postmenopausal women in clinical settings.
The purpose of this study was to investigate comorbidities associated with back pain, and to examine the relationship between baseline back pain and future fractures in Japanese postmenopausal women. The results indicated that the back pain can be a useful predictor for future vertebral fracture risks in clinical settings.
From the *Department of Gynecology and Obstetrics, Tokyo Women's Medical University, Tokyo, Japan; †Department of Internal Medicine, Research Institute and Practice for Involutional Diseases, Nagano, Japan; ‡Division of Clinical Trial Design and Management, Translational Research Center, Kyoto University, Kyoto, Japan; and §Department of Orthopedic Surgery, University of Occupational and Environmental Health School of Medicine, Kokura, Japan.
Acknowledgment date: October 15, 2008. Revision date: January 23, 2009. Acceptance date: February 9, 2009.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
Supported by a Grant-in-aid from Japan Ministry of Health, Welfare and Labor on Longevity (H-18-037).
Address correspondence and reprint requests to Masataka Shiraki, MD, PhD, Department of Internal Medicine, Research Institute and Practice for Involutional Diseases, 1610-1, Meisei, Misato, Azumino, Nagano 399-8101, Japan; E-mail: firstname.lastname@example.org.