Associations between Sex Hormones and Circulating Growth Differentiation Factor-15 in Male Patients with Major Depressive Disorder

The interaction between the endocrine system and inflammation is crucial pathogenesis of depression. Our study aimed at exploring the possible relationship between sex hormones and growth differentiation factor-15 (GDF-15), a common indicator of inflammation in male patients with major depressive disorder (MDD). Methods: GDF-15 levels of 121 male MDD patients were compared with 105 healthy subjects with the help of a Cobas 8000 automatic chemiluminescence immunoanalyzer. Results: (1) MDD patients showed higher GDF-15 levels, a lower testosterone (T) level and testosterone/estradiol ratio (T/E2 ratio) than healthy subjects (all p < 0.05). (2) Serum T levels and the T/E2 ratio were inversely associated with GDF-15 serum levels (all p < 0.05). (3) HAMD-24 scores were positively correlated with the levels of GDF-15 (p < 0.01), but not with T levels, estradiol (E2) levels, and the T/E2 ratio (all p > 0.05). Conclusion: The high level of GDF-15 was correlated with a low T/E2 ratio and T deficiency in male MDD patients. The above results demonstrate that up-regulation of serum GDF-15 and down-regulation of T and T/E2 ratio may be correlated with the occurrence and severity of depression. So, changing the level of GDF-15 by regulating the proportion of sex hormones may play a key role in the prognosis and treatment of depression.