A study in Australia found that men with anxiety disorders tended to have reduced bone mineral density in their lumbar spine and femoral neck bones. This association was found even when controlling for sociodemographic, biometric and lifestyle factors, other diseases, and medication use, but disappeared when participants with a history of mood disorders were excluded from the sample. The study was published in Acta Psychiatrica Scandinavica.
Bone mineral density refers to the quantity of minerals, primarily calcium and phosphorus, present in a segment of bone. It serves as an indicator of bone strength and density.
Studies have shown that certain psychiatric disorders might negatively impact bone health. These include unipolar depression, bipolar disorder, schizophrenia and anorexia nervosa. A meta-analytic review of 21 studies conducted in 2016 reported a very clear link between depression and reduced bone mineral density in several regions.
Strong evidence also exists for the link between anorexia nervosa and reduced bone mineral density. Anorexia nervosa is an eating disorder characterized by an intense fear of gaining weight and a distorted body image. This leads those suffering from it to eat very little, often literally starving themselves.
Study author Gregory Roebuck and his colleagues wanted to investigate the relationship between anxiety disorders and bone mineral density in women and men, while taking other factors that could influence this relationship into account. Given that anxiety disorders and depression often occur together, these researchers expected that having an anxiety disorder would be associated with lower bone mineral density and an increased rate of bone loss over time in both women and men.
This study used data from the Geelong Osteoporosis Study, a large research project launched back in 1993 with the intent to investigate the epidemiology of osteoporosis in Australia. The aims of the study have been expanding as time progressed.
Participants were drawn from the general population of the Barwon Statistical Division in Victoria, Australia. They were assessed when they joined the study and at regular intervals after that. This study used data from the start of the Geelong Osteoporosis study and from 10-year and 15-year assessments for women. For men, it was the start of the study, 5-year, and 15-year assessments. Data from 890 women and 785 were included in this study. Of these, 231 women and 93 men had anxiety disorders. Women were, on average, followed for 15 years and men for 11.
The researchers used data on the bone mineral density at the lumbar spine (L2-L4 sections) and femoral neck measures using dual energy X-ray absorptiometry. Dual energy X-ray absorptiometry (DXA) is a medical imaging technique that uses low-dose X-rays to measure bone mineral density and assess body composition.
The researchers also measured weight and height of participants, and collected demographic and lifestyle data using self-report questionnaires. In addition, they conducted structured clinical interviews in order to assess participants’ lifetime history of anxiety disorders.
Results showed that panic disorder was the most common anxiety disorder in both men and women. Women with anxiety disorders tended to be younger than those without it, more likely to smoke and to use antidepressant medication. They also tended to have higher bone mineral density at both lumbar spine and femoral neck compared to women without anxiety disorders.
Men with anxiety disorders were younger, taller, more likely to smoke, and more likely to use antidepressant medication. However, they had lower bone mineral density at the lumbar spine at the start of the study compared to men without anxiety disorders. Analysis of data from different time points showed that anxiety disorders were not associated with differences in the rate of change of bone mineral density over time.
When participants who, aside from anxiety disorders, also had mood disorders (primarily depression) were excluded from the study, the association between anxiety disorders and lumbar spine and femoral neck bone mineral density in men disappeared. This made researchers hypothesize that depression might be mediating the link between anxiety disorders and bone mineral density.
“In summary, this study found that men with a lifetime history of a DSM-IV-TR anxiety disorder had lower bone mineral density in the lumbar spine and femoral neck compared with healthy controls. These associations may have been mediated by comorbid depressive disorders, as they became non-significant when participants with a history of a mood disorder were excluded from the analysis,” the study authors concluded.
The study makes an important contribution to the scientific understanding of the links between psychiatric disorders and physiological changes. However, it also has limitations that need to be taken into account. Notably, some of the data about lifetime history of psychiatric disorders was based on participants’ recall of previous events. Additionally, there were potentially important factors, such as vitamin D levels, that were not taken into account.
The study, “Anxiety disorders are associated with reduced bone mineral density in men: Findings from the Geelong Osteoporosis Study”, was authored by Gregory Roebuck, Michael Mazzolini, Mohammadreza Mohebbi, Julie A. Pasco, Amanda L. Stuart, Malcolm Forbes, Michael Berk, and Lana Williams.
