The Association Among Serum Growth Differentiation Factor 15 Level and Suicidal Ideation is Dependent on Testosterone Deficiency in Depressive Patients

Rui Peng, Di Li, Si-Qing Mei, Yan Li Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, 430060, People’s Republic of ChinaCorrespondence: Yan LiDepartment of Clinical Laboratory, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, People’s Republic of ChinaTel +86 27 88071553Email pengruiwec@163.comBackground: Elevated levels of growth differentiation factor (GDF)-15 and reduced levels of testosterone have been linked to depressive disorder, but whether they are also linked to suicidal ideation in patients with depression is unclear.Methods: This retrospective study involved 301 patients ≥ 22 years old hospitalized for depression between July 2018 and November 2020 at Renmin Hospital of Wuhan University, of whom 120 had suicidal ideation. Serum levels of GDF-15 and testosterone were compared between patients with or without suicidal ideation.Results: GDF-15 levels were significantly higher among patients with suicidal ideation than among those without, regardless of whether testosterone levels were above or below the median of 314 ng/dL. In multivariate logistic regression involving all patients, serum GDF-15 level was associated with low testosterone level (P=0.001). Among patients with testosterone < 314 ng/dL, an increase of 1 standard deviation in serum GDF-15 level translated to a 1.3-fold increase in the risk of suicidal ideation (P=0.007). This relationship was not observed in all population or patients with testosterone levels ≥ 314 ng/dL.Conclusion: High serum GDF-15 level may be associated with an increased risk of suicidal ideation in patients with depression, and this association appears to be partly mediated by low testosterone levels.Keywords: growth differentiation factor-15, testosterone, suicidal ideation, major depressive disorder