title: Interleukin-6 and depressive symptom severity in response to physical exercise.
abstract: Elevated IL-6 has been implicated in depression. The anti-inflammatory effects of exercise may be associated with its clinical efficacy for depression. We determined if serum IL-6 levels were altered by 12 weeks of physical exercise, and if IL-6 levels were associated with baseline depression severity and change in depression severity in response to exercise. Data from 116 adults (42.7±11.5y) with mild-to-moderate depression (Patient Health Questionnaire >9) who participated in the physical exercise arm of the Regassa RCT (www.regassa.se) were analyzed. Participants were requested to complete three 60-min exercise sessions weekly for 12 weeks. Blood samples were provided at baseline and post-intervention following an overnight fast and were analyzed for serum levels of IL-6 using ELISA. IL-6 values were logarithm-transformed. Higher baseline serum IL-6 levels were significantly associated with reduced depression severity after exercise. Reduced IL-6 levels following exercise were significantly associated with parallel reductions in depression severity. These findings are consistent with a previously reported association between reduced serum IL-1β levels and reduced depression severity following 12 weeks of physical exercise in 105 depressed adults. Findings support associations between IL-6, depressive symptoms, and exercise response, and provide support for the plausible involvement of IL-6 in the antidepressive effect of exercise.
authors.affiliation: Department of Molecular Medicine and Surgery, Neurogenetics Unit, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Catharina
authors.initials: C
authors.lastname: Lavebratt
authors.affiliation: Department of Physical Education and Sport Sciences, University of Limerick, Ireland; Health Research Institute, University of Limerick, Ireland. Electronic address: matthew.herring@ul.ie.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Herring
authors.affiliation: Department of Molecular Medicine and Surgery, Neurogenetics Unit, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Jia Jia
authors.initials: JJ
authors.lastname: Liu
authors.affiliation: Department of Molecular Medicine and Surgery, Neurogenetics Unit, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Ya Bin
authors.initials: YB
authors.lastname: Wei
authors.affiliation: Department of Statistics, University of Padua, Padua, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Bossoli
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Hallgren
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Forsell
mesh_terms: D000328:Adult; D003863:Depression / Q000097:blood* / Q000628:therapy*; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D053583:Interleukin-1beta / Q000097:blood; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: C508600:IL6 protein, human; D053583:Interleukin-1beta; D015850:Interleukin-6
keywords: Cytokine; Depression; Exercise intervention; Inflammation; MADRS; Regassa