Exercise Intensity, Sex, And Obesity, But Not Ghrelin Affect Post Exercise Endothelial Function

INTRODUCTION: Ghrelin changes with acute exercise improve endothelial function (EF), although the relationship between exercise intensity, obesity status, sex, ghrelin, and EF is unclear. PURPOSE: To examine intensity, obesity status, and sex on the ghrelin and EF response to acute exercise. METHODS: 11 males (age: 40.72 ± 11.81 yrs; VO2peak 29.96 ml/kg/min; BMI 27.0 ± 6.0 kg/m2; 8 lean, 3 obese) and 9 females (age: 35.11 ± 10.40 yrs; VO2peak: 27.68 ± 5.90 ml/kg/min BMI: 25.24 ± 5.96 kg/m2, 7 lean, 2 obese) completed a maximal graded cardiopulmonary VO2peak/lactate threshold (LT) test on a cycle ergometer. These data were used to determine the exercise intensity for 2 subsequent randomized calorically matched cycle exercise bouts: a) MOD, the power output at LT; b) HIGH, the power output associated with 75% of the difference between LT and VO2peak; c) CON, no exercise. The timing of each visit was standardized and occurred at 0800 h. Brachial artery flow mediated dilation (FMD) was assessed at baseline (pre-exercise), and at 30 min, 60 min, 90 min, and 120 min post-exercise. Blood was collected at the same timepoints (n = 15) to measure total ghrelin (TG), acylated ghrelin (AG), and deacylated ghrelin (DAG). A linear mixed model to examine the response of FMD to exercise was used, with subject as a random factor and sex, obesity status, condition, and time as fixed factors. An ANOVA was then used to compare fixed effects. Pearson correlations were used to determine the relationship between each ghrelin and FMD. RESULTS: A main effect on ΔFMD was found for condition (MOD: 7.02 ± 1.67, HIGH, 7.13 ± 1.70 significantly higher than CON = 6.06 ± 1.28; p < 0.05). There was an interaction between condition and sex for ΔFMD in females and males between CON and both exercise conditions (MOD & HIGH; p < 0.01). Additionally, an interaction was found between exercise condition and BMI in lean individuals, with CON ΔFMD different from MOD and HIGH (all; p < 0.01). DG was correlated with ΔFMD (r = -0.219, p = 0.003). CONCLUSIONS: Exercise intensity, sex and obesity status affect post exercise endothelial function. These changes do not appear to be modulated by changes in ghrelin. UVA School of Education and Human Development and NIH NIDDK (R01 DK129510)