Decreased osteoprotegerin and increased bone turnover in young female patients with major depressive disorder and a lifetime history of anorexia nervosa

Low bone mineral density (BMD) is a frequent, often persistent complication in patients with major depressive disorder (MDD) and anorexia nervosa (AN) that increases the risk of pathologic fractures. The pathogenetic process underlying osteopenia in MDD and AN is still unclear, although several factors, including a dysbalance of cytokines, are associated with loss of bone mass. Alterations in the serum levels of cytokines have been observed in patients with MDD, AN, and other psychiatric disorders. Therefore, we examined serum levels of cytokines, markers of bone turnover, and BMD in 13 patients with MDD and a lifetime history of AN. Bone turnover markers (osteocalcin and C-terminal degradation products of type I collagen) and tumor necrosis factor alpha (TNF-alpha) in patients were significantly increased compared with those of the control group. Osteoprotegerin (OPG) in patients was significantly decreased. Eight of 13 patients (62%) displayed osteopenia at the lumbar spine. TNF-alpha correlated significantly with C-terminal degradation products of type I collagen, an osteoclastic marker, but significantly negatively with OPG. Our data suggest that TNF-alpha and OPG may play a role in the pathogenetic process underlying osteopenia in these patients.