Abstract
PURPOSE: The current study examined the relationship between exercise-induced changes in stress hormones (epinephrine, norepinephrine, and cortisol) and vascular inflammatory markers (soluble intracellular adhesion molecule-1 [sICAM-1], soluble endothelial selectin [sE-selectin], and soluble vascular adhesion molecule-1 [sVCAM-1]) in obese men over a 24-hour period following exercise at lower and higher intensity. PATIENTS AND METHODS: Fifteen physically inactive, obese, college-aged men performed a single bout of cycling exercise at lower and higher intensities (lower intensity: 50% of maximal heart rate, and higher intensity: 80% of maximal heart rate) in random order. Overnight fasting blood samples were collected at baseline, immediately postexercise (IPE), 1-hour PE (1-h PE), and 24-hour PE. Changes in stress hormones and inflammatory markers were analyzed with a repeated-measures analysis of variance using Bonferroni multiple comparisons and a linear regression analysis (p<0.05). RESULTS: sICAM-1, sVCAM-1, epinephrine, and norepinephrine did not change over time, while sE-selectin was significantly lower at 1-h PE (10.25±1.07 ng/mL, p=0.04) than at baseline (12.22±1.39 ng/mL). Cortisol and sICAM-1 were negatively related at 1-h PE following lower-intensity exercise (r(2)=0.34, p=0.02), whereas cortisol and sVCAM-1 were positively related at IPE following higher-intensity exercise (r(2)=0.36, p=0.02). CONCLUSION: Regardless of intensity, an acute bout of aerobic exercise may lower sE-selectin in sedentary obese men. Responses of cortisol are dependent on exercise intensity, and cortisol may be a key stress hormone playing a major role in regulating sICAM-1 and sVCAM-1.