Influência do ciclo menstrual e o uso de contraceptivos no controle autonômico cardíaco durante o repouso e na transição repouso-exercício

• Autor(a) principal: Teixeira, André Luiz da Silva
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/8251
• topic: Autonomic nervous system; Heart rate variability; Contraceptive agents; Estrogen; Progesterone; Sistema nervoso autônomo; Variabilidade da frequência cardíaca; Agentes contraceptivos; Estrogênio; Progesterona; Exercícios físicos Aspectos fisiológicos; Ciclo menstrual; Variabilidade do batimento cardíaco; Anticoncepcionais orais; CNPQ::CIENCIAS DA SAUDE::EDUCACAO FISICA

The menstrual cycle (MC) has a cyclical nature that lasts approximately 28 days in wich variations female sex hormones, particularly estrogen and progesterone, determine its three phases: follicular, ovulatory and luteal. The use of oral contraceptive pills (OCP) is a strategy often used by women to prevent pregnancy, in which a constant dosage of female hormones attenuates these cyclical variations. Due the cardiovascular effects related to female hormones, several studies were performed in order to assess the influence of MC on cardiac autonomic control at rest. In this sense, the present study aims to determine the influence of CM and the use of OCP on cardiac autonomic control at rest and rest to exercise transition. For this, three specific studies have been developed (one systematic review and two original papers). The results of systematic review showed that the different phases of MC may modify the heart rate variability (HRV) in non-users of OCP, wherein follicular phase is characterized by an increase in cardiac vagal activity and the luteal phase by an increase in sympathetic activity (Study 1). Through this review research, we observed that most studies used only women who did not use OCP, and the influence of OCP use in cardiovascular control needs to be further explored. Accordingly, we recruited 17 volunteers aged 19-31 years who were OCP users for at least six consecutives months, and analyzed the HRV during two phases: active phase of OCP use and placebo phase without the use of OCP. The results demonstrates that the HRV is not modified by the administration of OCP. We also seek to verify the influence of CM and the use of OCP on cardiac autonomic control at the onset of dynamic exercise (Study 3). For this, 13 non-OCP users and 17 OCP users were evaluated by the 4-seconds exercise test during three different phases of the MC (follicular, ovulatory and luteal). The results showed that the MC or OCP use does not modify the cardiac vagal withdrawal at the onset of dynamic exercise. These results allow us to conclude that the CM may modify the resting HRV in women not using OCP, and this change does not occur in OCP users. In addition, the cardiac vagal withdrawal at rest to exercise transition is not influenced by the different phases of the MC regardless of the use of OCP