Bone density and depression in premenopausal South African women: a pilot study

Abstract

Objective: It is posited that the effect of depression on BMD is dependent on the severity of depression. Conflicting evidence exists regarding this possible association. This study investigated the association between depression and low bone mineral density (BMD). Methods: The hypothesis was investigated in a random sample of volunteers (n=40) and in premenopausal female psychiatric patients (n=5) diagnosed with recurrent severe major depression. The outcome measures were BMD (DEXA); depression (Beck Depression Inventory and Psychological General Well-being Scale) and 24-hour saliva cortisol levels (ELISA). In a comparison of women (4 of the 40 i.e. “control” subjects) with negligible symptoms of depression and the five patients with severe recurrent major depression- BMD, depression, saliva cortisol and bone turnover markers were measured and compared. Pro-inflammatory status (IL-1 and TNF-alpha) was investigated in the psychiatric patients only. Results: In the random – non clinical - sample of women (n=40), 26 exhibited normal BMD and 14 exhibited low BMD. Depressive symptoms and cortisol levels
were not significantly different between these two groups. Women with severe recurrent major depression(n=5) exhibited lower median BMD T-scores, higher overall bone turnover and higher 24-hour cortisol levels compared to “control” subjects (n=4). The psychiatric patients also exhibited elevated IL-1 levels. Conclusion: The effect of depression on BMD may be dependent on the depression severity. IL-1 and cortisol are possible mediators in depression-induced BMD loss.

Key words: Bone mineral density; Cortisol; Depression; Pro-inflammatory cytokines