RESUMO
Post-exercise hypotension (PEH) is the phenomenon of lowered blood pressure after a single bout of exercise. Only a fraction of people develops PEH but its occurrence correlates well with long-term effects of sports on blood pressure. Therefore, PEH has been suggested as a suitable predictor for the effectivity of exercise as therapy in hypertension. Local vascular bioactive lipids might play a potential role in this context. We performed a cross-over clinical pilot study with 18 healthy volunteers to investigate the occurrence of PEH after a single short-term endurance exercise. Furthermore, we investigated the plasma lipid profile with focus on arachidonic acid (AA)-derived metabolites as potential biomarkers of PEH. A single bout of ergometer cycling induced a significant PEH in healthy volunteers with the expected high inter-individual variability. Targeted lipid spectrum analysis revealed significant upregulation of several lipids in the direct post-exercise phase. Among these changes, only 15- hydroxyeicosatetranoic acid (HETE) correlated significantly with the extent of PEH but in an AA-independent manner, suggesting that 15-HETE might act as specific PEH-marker. Our data indicate that specific lipid modulation might facilitate the identification of patients who will benefit from exercise activity in hypertension therapy. However, larger trials including hypertonic patients are necessary to verify the clinical value of this hypothesis.
Assuntos
Ácido Araquidônico/sangue , Exercício Físico , Ácidos Hidroxieicosatetraenoicos/sangue , Hipotensão Pós-Exercício/sangue , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/sangue , Adulto , Variação Biológica da População , Pressão Sanguínea/fisiologia , Estudos Cross-Over , Dinoprostona/sangue , Feminino , Voluntários Saudáveis , Frequência Cardíaca/fisiologia , Humanos , Hipertensão/fisiopatologia , Hipertensão/terapia , Metabolismo dos Lipídeos/fisiologia , Masculino , Projetos Piloto , Tromboxanos/sangueRESUMO
BACKGROUND: Passive hyperthermic exposure causes an acute hypotensive response following the cessation of heat stress. Chronic heat stress is well documented in animal studies to instigate metabolic and lipid alterations. However, it is unknown if exercise-heat acclimation also causes favorable chronic blood pressure, lipid, and immune responses in humans. PURPOSE: This project tested the hypothesis that 10-day exercise-heat acclimation (HA) would cause greater post-exercise reductions in arterial blood pressure and favorable metabolic, lipid, and immune responses compared to 10-day exercise under neutral conditions (CON). METHODS: Thirteen healthy sedentary participants (8M/5F, 28⯱â¯6y, 78⯱â¯17â¯kg), completed a 10-day (90â¯min/day exercise bout) clamped hyperthermia HA (increase internal temperature 1.5⯰C, in 42⯰C, 28% Rh) and control (CON: 23⯰C, 42% Rh) protocols in a counterbalanced design with a 2 month washout. Pre- and post-exercise HA/CON blood pressures were taken 1-h post-exercise on exercise days 1 and 10. Metabolic, lipid and immune panels were taken pre-post HA/CON. RESULTS: Exercise under heat stress had greater post-exercise hypotension (systolic; -6â¯mmHg, diastolic; -8â¯mmHg; and mean arterial pressure; -7â¯mmHg) on both days 1 and 10 compared to exercise under neutral conditions (main effect for condition, Pâ¯≤â¯0.004). Only from pre-to-post HA, total cholesterol (168⯱â¯19 to 157⯱â¯15; Pâ¯<â¯0.03) and triglycerides (137⯱â¯45 to 111⯱â¯30; Pâ¯<â¯0.03) were reduced, while absolute lymphocytes (-26%), monocytes (-22%), and basophils (-49%) significantly decreased (each Pâ¯≤â¯0.04). Relative values of neutrophils increased (18%) and lymphocytes decreased (-20%) only after HA (Pâ¯≤â¯0.04). CONCLUSION: These data indicate that exercise in the heat (regardless of acclimation status) causes a profound post-exercise hypotensive response, while HA causes favorable lipid, and immune profile changes. Further examination of exercise-heat acclimation on vascular, metabolic, and immune responses will offer insight for benefits in other clinical populations with vascular, metabolic and immune dysfunction.
Assuntos
Aclimatação , Exercício Físico/fisiologia , Temperatura Alta , Hipotensão Pós-Exercício/sangue , Hipotensão Pós-Exercício/imunologia , Adulto , Pressão Sanguínea , Temperatura Corporal , Colesterol/sangue , Estudos Cross-Over , Feminino , Frequência Cardíaca , Humanos , Contagem de Leucócitos , Masculino , Triglicerídeos/sangue , Adulto JovemRESUMO
UNLABELLED: Antioxidants can decrease oxidative stress and combined with acute exercise they may lead to further decreases in blood pressure. The purpose of this study was to investigate the effects of 2 weeks of antioxidant supplementation on vascular distensibility and cardiovascular hemodynamics during postexercise hypotension. METHODS: Twenty young subjects were randomized to placebo (n = 10) or antioxidant supplementation (n = 10) for two weeks. Antioxidant status, vascular distensibility, and hemodynamics were obtained before, immediately, and 30 minutes after an acute bout of aerobic exercise both before and after supplementation. RESULTS: Two weeks of antioxidant supplementation resulted in a greater systolic blood pressure (SBP) decrease during postexercise hypotension (PEH) and significant decreases in augmentation index versus placebo (12.5% versus 3.5%, resp.). Also ferric-reducing ability of plasma (FRAP) increased significantly (interaction P = 0.024) after supplementation. CONCLUSION: Supplementation showed an additive effect on PEH associated with increased FRAP values and decreases in systolic blood pressure and augmentation index.