Associations Of Inflammation, Anxiety, And Exercise Response In The Tiger Study

Abstract

Exercise has been shown to improve anxiety, potentially via effects on adiposity and inflammation. This hypothesis is understudied. PURPOSE: To examine associations between inflammatory markers and anxiety before and after 15-wks of aerobic exercise training and potential variation based on obesity and anxiety status. METHODS: Anxiety (State-Trait Anxiety Inventory; STAI-Y2) and inflammatory markers (CRP, IFN-γ, IL-10, IL-12p70, IL-1β, IL-6, IL-8, and TNF-α) were measured in 177 TIGER Study participants (61 M; 116 F), aged 18-35 (21±3) y, who met the study’s minimum prescribed exercise dose. Regression, adjusted for age, race/ethnicity, psychotropic drug use, and cohort examined associations among outcomes at baseline and 15 wks along with associated change. Change models were adjusted for dose. Stratified models examined differences based on gender, obesity, and high trait anxiety. RESULTS: At baseline ∼18% of participants were obese (14M; 18F); 13% reported STAI-Y2 >1SD above the norm (5M; 18F). Among men: baseline IL-6/TNF-α ratio was inversely associated with anxiety (p<.02); baseline anxiety was positively associated with change in CRP (p<.03); and, change in IL-8 was inversely associated with change in anxiety (p<.02). Associations differed based on obesity. Among non-obese men, IL-6, IL-6/IL-10, and IL-6/TNF-α were inversely associated with anxiety (all p<.05); baseline anxiety was positively associated with change in CRP and inversely associated with change in IL-1β (all p<.01); and, changes in IL-6 and IL-8 were inversely associated with change in anxiety (all p<.04). Among obese men, baseline IL-6/IL-10, and IL-6/TNF-α were positively associated with change in anxiety (all p<.05). Among women, associations varied based on obesity and anxiety status. Among obese women, baseline IL-1β was positively associated with change in anxiety (all p<.03). Among non-high trait anxious women, baseline CRP was positively associated with anxiety (p<.01). Among high trait anxious women, baseline anxiety was inversely associated with change in IL-8 and change in IFN-γ was inversely associated with change in anxiety (all p<.03). CONCLUSION: Preliminary findings support potential links between inflammatory markers, anxiety, and exercise response in young adults which may vary based on gender, obesity, and anxiety severity.