Circulating myokines IL-6, IL-15 and FGF21 response to training is altered by exercise type but not by menopause in women with obesity.

To examine the effects of a time-matched endurance vs. concurrent training on circulating IL-6, IL-13, IL-15, IL-15Ra, FGF21 levels in postmenopausal women with obesity, and to determine these myokines response to endurance training pre- and postmenopause. Thirty-five sedentary postmenopausal women with obesity were randomly divided into endurance training (EN1, N = 10), concurrent training (CON, N = 13) or no training group (CT, N = 12). Additionally, twelve sedentary premenopausal women with obesity were added to an endurance training group (EN2, N = 12). Participants took part in a 12-week supervised intervention, performing 3 sessions/week of 60 min/session. Before and after the interventions, body composition and fitness were assessed, and blood samples obtained to measure serum myokines levels. Total fat mass decreased in all exercised groups (CON,-5.2%; EN1,-5.3%; EN2,-5.6%). In postmenopausal women, serum IL-6, IL-15 and IL-15Ra decreased after training (P<0.01), finding a pronounced reduction in IL-6 (-42% vs. -16%) and IL-15 (-50% vs. -31%) when comparing EN1 to CON (P<0.05). Serum FGF21 was only reduced in the EN1 (-27%; P=0.012). While EN1 and EN2 comparison, reported differences for IL-15Rα concentration (-28% vs. -40%; P=0.023). Finally, in EN2, the delta change of fat mass and IL-6, IL-15 and IL-15Rα were associated (r = 0.605; r = 0.546; r = 0.515; P<0.05). IL-13 showed undetected concentrations. Circulating IL-6, IL-15 and FGF21 response to training is altered by exercise type but not by menopause in women with obesity. Endurance training promotes a higher reduction of these myokines, potentially activating their intricate immune and fat mass regulation roles in postmenopausal women with obesity.