Association of Physical Activity and Bone Mineral Density in Adults with Depressive Symptoms.

Depression affects a significant proportion of adults in the United States. Studies exploring the association between depression and bone mineral density (BMD) have shown mixed results. Moreover, the relationship between BMD and physical activity (PA) in individuals with depressive symptoms is unknown. In this paper, we evaluated the association of depressive symptoms and PA with BMD, as well as difference in BMD among females with depressive symptoms before and after menopause.Data from the 2011-2018 National Health and Nutrition Examination Survey were used. Multivariable linear regression was used to explore the relationship between BMD and exposure variables.The study included 9,238 participants, of whom 766 had depressive symptoms. The presence and severity of depressive symptoms were significantly associated with lower BMD (aCoef.=-0.0200 for depressive symptoms, -0.0017 for depressive symptom severity; p<0.001). Vigorous PA intensity was positively correlated with BMD, with and without controlling for depressive symptoms (aCoef.=0.0006; CI=[0.0003, 0.0008]; p<0.001). Additionally, high levels of vigorous PA showed a significant positive relationship with BMD (aCoef.=0.0141; CI=[0.0078, 0.0205]; p<0.001). Postmenopausal status was significantly associated with lower BMD. No significant interaction effects were observed between depressive symptoms and PA or menopausal status on BMD.Our study demonstrated the an association between depressive symptoms and low BMD, as well as a positive association between high-intensity vigorous PA and BMD. Future studies should aim to replicate our findings and evaluate the underlying mechanisms.