Reduction in blood pressure after cycle ergometer exercise and its physiological regulators: influence of time and association with hormone variation.

• Register: REBEC
• Last refreshed on: 29 April 2013
• Main ID: RBR-3hkqg9
• Date of registration: 13/02/2012
• Primary sponsor: Escola de Educação Física e Esporte da Universidade de São Paulo - Brazil
• Public title: Reduction in blood pressure after cycle ergometer exercise and its physiological regulators: influence of time and association with hormone variation.
• Scientific title: Post-Aerobic Exercise Hypotension and its Hemodynamic and Neural Mechanisms in Pre-Hypertensives: influence of time and association with circadian endocrine regulation.
• Date of first enrolment: 01/06/2011
• Target sample size: 16
• Recruitment status: not yet recruiting
• URL: http://www.ensaiosclinicos.gov.br/rg/RBR-3hkqg9/
• Study design: Randomized clinical trial, with 2 arms, and conducted with a cross-over design.

Countries of recruitment

Brazil

Contacts

• Name: Claudia Forjaz
• Affiliation: Escola de Educação Física e Esporte da Universidade de São Paulo

• Name: Claudia Forjaz
• Affiliation: Escola de Educação Física e Esporte da Universidade de São Paulo

Key inclusion & exclusion criteria

Inclusion criteria: Men
Aged between 20 and 40 years
Systolic blood pressure between 120-139 mmHg and/or diastolic 80-89 mmHg
No diabetes
Sedentary or insufficiently active (did not perform physical activity more than twice a week)
Non smokers
Do not take any medicine that affects the cardiovascular system

Exclusion criteria: Body Mass Index of equal to or greater than 30kg/m2
Subjects with cardiac diseases (previous diganosis or elatered rest or exercise ECG)
Individuals that are experiencing poor quality sleep (score greater than 5 at Pitsburg Sleep Quality Index)
- Not having chronotype intermediary, or be morning or evening


Age minimum: 20Y
Age maximum: 40Y
Gender: M

Health Condition(s) or Problem(s) studied

Pre-hypertension
R03

Intervention(s)

A single group of pre-hypertensive subjects will undergo 4 experimental sessions: one with exercise (cycle ergometer, 45min, 50% of VO2peak)conducted in the morning (9am), one with exercise (cycle ergometer, 45min, 50% of VO2peak)conducted in the evening (6:30 pm), one without exercise (control - sitting rest) conducted in the morning (9 am) and one without exercise (sitting resting) conducted in the evening (6:30 pm). The order of the execution of these sessions will be randomized for each subject. An interval of at least 48 hours will be garanteed between the sessions.

Primary Outcome(s)

Postexercise hypotension - evaluated by the measurement of clinic (auscultatory) and ambulatory (oscillometric) blood pressure before and after rest and aerobic exercise performed in the morning and evening.

Secondary Outcome(s)

Autonomic modulation - evaluated by measuring heart rate and blood pressure variabilities (spectral analysis) performed before and after rest and aerobic exercise conducted in the morning and evening.

Circadian endocrine regulation - evaluated by plasma levels of norepinephrine, epinephrine, angiotensin II, and vasopressin, besides the urinary melatonin metabolite 6-sulfatoxymelathonin.

Função vascular - avaliada pela medida do fluxo sanguíneo basal e de sua resposta a manobra de hiperemia reativa (pletismografia de oclusão venosa) realizada antes e após o repouso e exercício aeróbico pela manhã e ao final da tarde.

Hemodynamics - evaluated by the measurement of cardiac output (rebreathing of carbon dioxide) and heart rate (ECG) before and after rest and aerobic exercise performed in the morning and evening. From such data, peripheral vascular resistance and stroke volume are going to be calculated.

Secondary ID(s)

CAAE - 0018.0.342.000-11

2011/17

Source(s) of Monetary Support

Conselho Nacional de Desenvolvimento Científico e Tecnológico - Brazil

Secondary Sponsor(s)

Laboratóio de Rins e Hormônios da Escola Paulista de Medicina da Universidade Federal de São Paulo - Brazil

Laboratório de Neurobiologia do Instituto de Ciências Biomédicas da Universidade de São Paulo - Brazil