Abstract 4088: Dynamic Exercise Can Acutely Increase Circulating Adiponectin
Introduction: Physical exercise has been associated with significant cardiovascular benefits. One of the proposed benefits of exercise training is the improvement of endothelial function and reduction in inflammatory activation as evidenced by a decrease in circulating C-reactive protein or a rise of the anti-inflammatory factor adiponectin. This protective factor is primarily released by the fat tissue and it is not fully understood how exercise training can enhance its release. We were interested in examining if even a single bout of treadmill exercise would be able to raise adiponectin levels in humans.
Methods: Human volunteer subjects (n=7, body mass index 26.3±0.96) underwent a treadmill exercise test and blood was drawn before, immediately after and one hour after exercise. Circulating plasma adiponectin levels and norepinephrine levels as well as clinical data were collected on all subjects. Norepinephrine data is presented as mean±s.e.m. picograms/ml (pg/ml) and adiponectin levels are shown as mean±s.e.m. micrograms/ml (mcg/ml). Statistical analysis was performed with a Friedman test with Dunns corrections for multiple comparisons.
Results: As anticipated, norepinephrine levels increased significantly (p=0.003)with norepinephrine levels rising from baseline levels of 426±70 pg/ml to 936±144 pg/ml and then returned to 347±44 pg/ml. Adiponectin levels did not increase immediately after exercise (17.2±2.0 mcg/ml to 18.1±2.2 mcg/ml), but then increased significantly after 1 hour to 43.0±3.0 mcg/ml (p<0.05). There was no correlation between body mass index and exercise induced adiponectin release.
Conclusions: While it has previously been shown that exercise training can increase circulating plasma levels of the vasculoprotective factor adiponectin, we now demonstrate that even a single bout of exercise can significantly increase circulating adiponectin levels. One mechanism that could potentially drive this effect could be the sympathetic activation that occurs with acute exercise. Future studies need to identify the the mechansims underlying this increase in adiponectin, as this may lead to novel therapies that utilize endogenous vasculoprotective factors.