Author(s): LI, J., JIN, Z., THACKRAY, A., KING, J., MOULD, C., MIYASHITA, M., STENSEL, D., Institution: LOUGHBOROUGH UNIVERSITY, Country: UNITED KINGDOM, Abstract-ID: 2052

INTRODUCTION:
Growth differentiation factor 15 (GDF15) is a cellular stress-induced cytokine elevated in disease states and associated with appetite suppression. Acute moderate-to-high-intensity exercise transiently suppresses appetite, but its effects on GDF15 and the relationship between exercise-induced GDF15 and appetite or energy intake remain unclear. This study aimed to examine the effects of acute exercise on GDF15, appetite, and energy intake, and their associations.
METHODS:
Twenty healthy-weight adults (10 men, 10 women; age 24.9 ± 4.2 years; body mass index 22.2 ± 2.0 kg·m-2) completed a randomized crossover study involving a 60-min run at 70% VO2peak and a resting control trial. After an overnight fast, plasma GDF15 and subjective appetite (hunger, fullness, satiety, prospective food consumption) were assessed pre- and post-exercise/control (t = 0 and 60 min), during recovery (t = 90 and 120 min; the latter immediately before the ad libitum meal), and at t = 150 (immediately after the meal), 180, and 210 min. Linear mixed models were used to examine trial effects on energy intake, fasting and incremental area under curve (iAUC) for GDF15 (0-120 and 0-210 min), adjusting for age, sex, and body mass index. Time-dependent responses were assessed using trial × time interactions. Associations between GDF15 and appetite perception iAUCs (0-120 and 0-210 min), and energy intake were examined using Spearman correlations. Statistical significance was set at P < 0.05.
RESULTS:
No trial effect was observed on energy intake (exercise minus control mean difference [95% CI]: 167.0 [-342.0, 675.0] kJ, P = 0.501). Baseline GDF15 concentrations were similar between trials (control: 339.0 [288.0, 390.0] pg·mL⁻¹; exercise: 354.0 [303.0, 406.0] pg·mL⁻¹; exercise minus control: 15.1 [-28.6, 58.8] pg·mL⁻¹, P = 0.478). Exercise significantly increased GDF15 iAUC both before the meal and across the entire trial (58.0 [34.6, 81.4] and 102.0 [57.7, 147.0] pg∙mL-1∙h-1, respectively; both P < 0.001). Baseline appetite perceptions did not differ between trials (all P ≥ 0.098), and no trial effects were observed for appetite iAUCs (0-120 and 0-210 min; all P ≥ 0.061), except that pre-meal satiety iAUC was significantly higher during the exercise trial (exercise minus control: 5.6 [1.1, 10.1] mm∙h-1, P = 0.018). A significant trial × time interaction was observed for GDF15 (P < 0.001), with higher concentrations in the exercise trial from 60 to 210 min (all P ≤ 0.005). No significant associations were observed between GDF15 iAUC and appetite iAUCs (all P ≥ 0.101), except for a positive association between pre-meal iAUCs for GDF15 and satiety (r = 0.56, P = 0.023).
CONCLUSION:
GDF15 increased after 1 h of moderate-to-vigorous intensity exercise in healthy individuals and remained elevated during the subsequent 2.5-h recovery period. Exercise-induced increase in GDF15 is not correlated with energy intake but is correlated with increased pre-meal satiety.