Abstract
OBJECTIVE: Certain psychiatric disorders, including depression, appear to impact adversely on bone health. Anxiety disorders are highly prevalent but few studies have examined their effects on bone tissue. This study investigated the effect of anxiety disorders on bone mineral density (BMD). METHODS: This prospective cohort study used data from the Geelong Osteoporosis Study. Participants were women and men aged ≥20 years randomly selected from the electoral roll and followed up for a mean of 14.7 and 11.0 years, respectively. Participants were assessed for a lifetime history of an anxiety disorder using the Structured Clinical Interview for DSM-IV-TR. BMD in the lumbar spine and femoral neck was measured using dual-energy x-ray absorptiometry. RESULTS: Eight hundred and ninety women and 785 men participated in the study. Adjusting for sociodemographic, biometric and lifestyle factors, medical comorbidities and medication use, anxiety disorders were associated with reduced BMD at the lumbar spine (partial η(2) = 0.006; p = 0.018) and femoral neck (partial η(2) = 0.006; p = 0.003) in men. These associations became non-significant when men with a history of comorbid mood disorders were excluded from the analysis. There was no significant association between anxiety disorders and BMD in women (p ≥ 0.168). CONCLUSIONS: Anxiety disorders are associated with reduced BMD in men. This effect may be mediated by comorbid depression.