Blood pressure responses during resistance exercise in hypertensive patients: influence of beta-blockers

• Grant number: 06/06356-8
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2007
• End date: April 30, 2009
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Cláudia Lúcia de Moraes Forjaz
• Grantee: Cláudia Lúcia de Moraes Forjaz
• Host Institution: Escola de Educação Física e Esporte (EEFE). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Recently, resistance exercise has been included, as a complementary training modality for skeletal and muscle improvement, in the exercise program recommended for hypertensive patients. Nevertheless, the few studies that analyzed intraarterial blood pressure responses during resistance exercise observed an exacerbated increase that might represent a risk to the patient. However, theses studies are conducted in patients without anti-hypertensive treatment, which might reduce blood pressure increase during exercise. Among the anti-hypertensive drugs, beta-blockers are used by many hypertensive patients, produce significant decreases in blood pressure responses to aerobic exercise, and might also reduce blood pressure increase during resistance exercise by the reduction of heart rate that is responsible for part of the blood pressure increase during this kind of exercise. Besides these comments, another important aspect in this area of investigation is that blood pressure measurement during resistance exercise should be performed by the intra-arterial method, since other methods are not validated for this condition. Since intra-arterial measurements are invasive, this aspect limits a lot knowledge production in this scientific field, being important to evaluate other methods for blood pressure measurement in this condition. Based on these aspects, the present study was designed to evaluate blood pressure response during resistance exercise of different intensities in hypertensive subjects with and without beta-blockers use, and to compare blood pressure values and response measured with intraarterial and plethismographic techniques. Ten essential level 1 and 2 (blood pressure lower than 160/105 mmHg) hypertensive patients without end-organ damage will be investigated in two occasions: receiving placebo and receiving atenolol (25 or 50 mg twice a day) for 6 weeks in a blind way. In each experimental session, intraarterial blood pressure will be measured in the radial artery of one arm, while indirect plethismographyc beat-by-beat blood pressure (Finometer) will be measured in the medium finger of the other arm. Blood pressure will be measured before and during 3 leg-extension exercise protocols (in a random order): a) 1 repetition at 100% of 1 repetition maximum (RM); b) 3 sets until exhaustion at 40% of 1RM; and c) 3 sets until exhaustion at 80% of 1 RM. In multiple sets exercises, an interval of 90 seconds will be maintained between sets. Moreover, between exercises there will be an interval until blood pressure values return to pre-exercise level, and this interval will last for at least 10 minutes. In each phase of the study (placebo and atenolol), before the experimental protocol, subjects will undergo familiarization sessions to the resistance exercise and also a 1RM test. Data measured before and during exercise in the 2 phases will be compared by a two-way ANOVA for repeated measures. Data from intraarterial and plethismographic measurements will be compared by Pearson correlation, t test and the agreement limits. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

GOMIDES, RICARDO S.; COSTA, LUIZ A. R.; SOUZA, DINOELIA R.; QUEIROZ, ANDREIA C. C.; FERNANDES, JOAO R. C.; ORTEGA, KATIA C.; MION JUNIOR, DECIO; TINUCCI, TAIS; FORJAZ, CLAUDIA L. M.. Atenolol blunts blood pressure increase during dynamic resistance exercise in hypertensives. BRITISH JOURNAL OF CLINICAL PHARMACOLOGY, v. 70, n. 5, p. 664-673, NOV 2010. (06/06356-8)