Asymptomatic vertebral deformity as a major risk factor for subsequent fractures and mortality: a long-term prospective study

Abstract

In elderly men and women, asymptomatic vertebral deformity was found to be associated with subsequent risk of symptomatic fractures, particularly vertebral fracture, and increased risk of mortality after a fracture.

Introduction: Vertebral deformity is associated with an increased risk of fracture and mortality. However, it is unclear whether the three events of vertebral deformity, fracture, and mortality are linked with each other and what role BMD plays in these linkages.

Materials and methods: Vertebral deformity was determined from quantitative analysis of thoracolumbar spine X-rays in 300 randomly individuals (114 men and 186 women) 60 years of age (as of mid-1989), who were randomly selected from the prospective Dubbo Osteoporosis Epidemiology Study. Incidence of atraumatic fractures and subsequent mortality were ascertained from 1989 to 2003. Cox's proportional hazards model was used to determine the association between asymptomatic vertebral deformities, osteoporotic fractures, and risk of mortality.

Results: The prevalence of asymptomatic vertebral deformity was 31% in men and 17% in women. During the follow-up period, subjects with vertebral deformity had a significantly higher risk of any fracture than those without vertebral deformity (44% versus 29%; hazards ratio [HR], 2.2; 95% CI, 1.4-3.7), particularly symptomatic vertebral fracture (relative risk [RR], 7.4; 95% CI, 3.2-17.0). Mortality rate was highest after a symptomatic fracture among those with vertebral deformity (HR, 9.0; 95% CI, 3.1-26.0). These associations were independent of age, sex, and BMD.

Conclusion: Vertebral deformity was a strong predictor of subsequent risk of fractures, particularly symptomatic vertebral fracture, and may modify fracture-associated mortality in both elderly men and women.