Influences Of An Acute Exercise Bout On Insulin-like Growth Factor-1 In Major Depressive Disorder

Insulin-like growth factor-1 (IGF-1) has important neurological functions (e.g., hippocampal neurogenesis) that may be altered in Major Depressive Disorder (MDD). Acute exercise can increase peripheral and central IGF-1 that, when completed over time, may lead to decreased depression symptomology. However, IGF-1 changes to acute exercise may be moderated by a variety of depression-relevant factors. PURPOSE: To determine potential moderation of changes in IGF-1 following maximal exercise by depression severity, antidepressant usage and regular physical activity behaviors. METHODS: Data was collected from adults between the ages of 18-65 in Berlin, Germany (n = 147). Demographics, blood draws pre- and post-maximal exercise, depression severity (Hamilton Rating Scale for Depression), antidepressant usage and moderate-to-vigorous physical activity (MVPA; International Physical Activity Questionnaire) were reported. Depression severity was categorized: mild (8-16) and moderate (17-23) using the HAM-D. MVPA was categorized using standard IPAQ rules. Linear regressions modeled associations between severity (mild, moderate, healthy control), antidepressant use (yes, no, healthy control) and MVPA (inactive, minimally active, health-enhancing physical activity) with post-exercise IGF-1, controlling for baseline IGF-1, age and sex; group mean changes were compared via Cohen’s d. RESULTS: Depression severity was not a significant predictor of post-exercise IGF-1 (p > 0.05) with small mean change differences between groups (all d < 0.05). Antidepressant usage was not a significant predictor of post-exercise IGF-1 (p > 0.05) with small mean change differences between groups (all d < 0.15). Activity level was not a significant predictor of post-exercise IGF-1 (p > 0.05), although there was a moderate difference in IGF-1 change between inactive and minimally active (d = 0.58). CONCLUSION: Increases in IGF-1 occurred similarly in both healthy individuals and those with MDD. Depression severity, antidepressants and chronic physical activity did not influence these changes; adults with MDD are likely to have a favorable exercise-induced IGF-1 increase, regardless of major clinical and behavioral differences which supports the broad recommendation of exercise during treatment for adults with MDD. This work was supported by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG, grant HE7464/2-1). Work by SK and JM was partially supported by NIMH grant #1R61MH129407-01A1.