Agerelated hyperkyphosis independent of spinal o

Authors: W B Katzman E Vittinghoff D M Kado

Publish Date: 2010/05/18

Volume: 22, Issue: 1, Pages: 85-90

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Abstract

While many assume hyperkyphosis reflects underlying spinal osteoporosis and vertebral fractures our results suggest hyperkyphosis is independently associated with decreased mobility Hyperyphosis is associated with slower Timed Up and Go performance times and may be a useful clinical marker signaling the need for evaluation of vertebral fracture and falling riskWhile multiple studies have demonstrated negative effects of hyperkyphosis on physical function none have disentangled the relationship between hyperkyphosis impaired function and underlying spinal osteoporosis The purpose of this study is to determine whether kyphosis independent of spinal osteoporosis is associated with mobility on the Timed Up and Go and to quantify effects of other factors contributing to impaired mobilityWe used data for 3108 communitydwelling women aged 5580 years in the Fracture Intervention Trial All participants had measurements of kyphosis mobility time on the Timed Up and Go test height weight total hip bone mineral density BMD grip strength and vertebral fractures at baseline visits in 1993 Demographic characteristics included age and smoking status We calculated mean Timed Up and Go time by quartile of kyphosis Using multivariate linear regression we estimated the independent association of kyphosis with mobility time and quantified effects of other covariates on mobilityMean mobility time increased from 93 s in the lowest to 101 s in the highest quartile of kyphosis In a multivariateadjusted model mobility time increased 011 s p = 002 for each standard deviation 119° increase in kyphosis Longer performance times were significantly associated with increasing age decreasing grip strength vertebral fractures body mass index ≥25 and total hip BMD in the osteoporotic rangeKyphosis angle is independently associated with decreased mobility on the Timed Up and Go which is in turn correlated with increased fall risk Hyperkyphosis may be a useful clinical marker signaling the need for evaluation of vertebral fracture and falling riskThis research was supported by the UCSFKaiser Building Interdisciplinary Research Careers in Women’s Health BIRCWH and cofunded by the National Institute of Child Health and Human Development NICHD and the Office of Research on Women’s Health ORWH 5 K12 HD052163Agerelated hyperkyphosis is an exaggerated anterior curvature of the thoracic spine Older adults with hyperkyphosis are at increased risk for impaired physical function 1 2 3 4 5 6 falls 7 and fractures 8 While multiple studies have demonstrated a negative effect of hyperkyphosis on physical function 1 3 5 6 9 10 none have been able to disentangle whether the impaired function might be explained by another associated predictor underlying spinal osteoporosis 11 Furthermore these studies have been limited by small sample sizes 3 qualitative measures of kyphosis 1 5 or lack of control of confounding variables 1 3 9 10As impaired physical function itself is associated with fall risk and fractures further examination of the relationship between kyphosis and measured physical function might inform other treatment strategies to forestall or even prevent functional decline Currently physicians often will refer patients to physical therapy for problems with balance and gait but there are few referrals for hyperkyphosis The association between hyperkyphosis and advanced age decreased grip strength low bone mineral density and vertebral compression fractures 1 5 12 13 14 15 16 that themselves can impact on physical function may serve to downplay the importance of agerelated postural change As an example even though only 3637 of older persons with the worst degrees of kyphosis have underlying vertebral fractures 13 17 most clinicians assume vertebral fractures are the cause of hyperkyphosis and may therefore consider it an incidental finding rather than an important clinical condition worthy of treatment itself 18 19 Establishing hyperkyphosis as a significant predictor of impaired mobility independent of other significant predictors likely to impair mobility could help justify intervention to reduce or delay progression of hyperkyphosis Currently interventions targeting easily modifiable impairments that contribute to kyphosis progression 20 21 22 23 24 25 26 27 including exercise and bracing are not widely used

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