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Menopause Live - IMS Updates
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Date of release: 14 September, 2009

Back pain and risk for future vertebral fractures


Back pain is a very common complaint and may be associated with various etiologies, among which osteoarthritis, discopathy and spinal stenosis are probably the most prevalent in the postmenopausal period. Osteoporosis per se, without a fracture or a change in vertebral morphology, is usually considered a silent disease condition. A recently published study in Japan [1], which recruited ambulatory postmenopausal women visiting their physician with back pain as a chief complaint, investigated possible co-morbidities and followed those women for future fractures (mean age at entry 62 ± 10 years, mean follow-up 5.7 ± 3 years). Each woman underwent bone densitometry and spinal radiography as part of the initial work-out. Patients who received medications that might affect bone metabolism (including vitamin D) and those severely ill or diagnosed as suffering from secondary osteoporosis or metabolic bone disease were excluded from the cohort. During the observation period, spine radiographs were done routinely every 1–2 years, or when there appeared symptoms suggestive of a fracture.


 


At baseline, 12% had prevalent fractures (vertebral, 9% or long bones, 3%), 18% had osteoporosis, 23% had osteoarthritis (based on the Kellgren–Lawrence score), and 4% suffered from rheumatoid arthritis. During the observation period, 23% developed a fracture without a high-energy trauma, mostly (78%) at the spine. A multivariate Cox regression analysis which included age, bone mineral density, pre-existing vertebral fracture and back pain as risk factors, demonstrated an independent contribution to the risk of future fractures for all the above factors that were included in the model. Osteoporosis by a bone mineral density testing was associated with a hazard ratio of 2.3 (95% confidence interval (CI) 1.23–1.50), and the values for a prevalent vertebral fracture and back pain were 1.92 (95% CI 1.20–3.06) and 1.62 (95% CI 1.16–2.27), respectively.

Comment

Women complain of back pain more often than men [2]. This very common symptom is usually attributed to spine deformity, a degenerative or an inflammatory process, and, in the absence of evidence of clinical or subclinical vertebral fracture, it is not considered a marker for bone fragility. In my clinic as a general practitioner, I often tell my patients that osteoporosis does not ache unless a fracture has occurred and that back pain has nothing to do with decisions on the need to treat osteoporosis. Now I am in doubt, since the study by Kuroda and colleagues [1] showed that back pain is an independent risk factor (after adjustments for age, bone mineral density and pre-existing fractures) that may predict future vertebral fractures. However, in a previous study by Nevitt and colleagues [3], no association between back pain during the year prior to recruitment and future incident vertebral fracture risk was recorded in a population-based cohort of volunteers. It is noteworthy that the cohort of Kuroda and colleagues [1] had different characteristics since it consisted of patients visiting their practitioner and complaining of back pain. The etiology of back pain is multifactorial and complex and there is no clear explanation for its association with vertebral fractures in non-osteoporotic patients. Recent studies have demonstrated a decrease in intervertebral disc height as a result of postmenopausal estrogen deficiency. Such changes may increase the likelihood of fractures because the buffering effect of the discs on forces applied to the spine become smaller. Nevertheless, regardless of pathophysiology, if further studies point at the same association, back pain should be accounted as an additional parameter in the therapeutic decision model when considering the prevention of osteoporotic fractures.

Comentario

Amos Pines
Department of Medicine T, Ichilov Hospital, Tel-Aviv, Israel

    References

  1. Kuroda T, Shiraki M, Tanaka S, Shiraki Y, Narusawa K, Nakamura T. The relationship between back pain and future vertebral fracture in postmenopausal women. Spine 2009;34:1984-9. Published August 15, 2009.
    http://www.ncbi.nlm.nih.gov/pubmed/19680106

  2. Hartvigsen J, Christensen K, Frederiksen H. Back and neck pain exhibit many common features in old age: a population-based study of 4,486 Danish twins 70102 years of age. Spine 2004;29:576-80.
    http://www.ncbi.nlm.nih.gov/pubmed/15129076

  3. Nevitt MC, Cummings SR, Stone KL, et al. Risk factors for a first-incident radiographic vertebral fracture in women > or = 65 years of age: the study of osteoporotic fractures. J Bone Miner Res 2005;20:131-40.
    http://www.ncbi.nlm.nih.gov/pubmed/15619679