Exercise and Neurovascular Function During Pregnancy
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 64
- 试验地点
- 2
- 主要终点
- Sympathetic Nerve Activity - cold pressor test response
研究概览
简要总结
Maintenance of a healthy pregnancy depends on an appropriate adaptation and responsiveness of blood vessels, to ensure appropriate blood flow to the fetus during everyday stressors. Previous work by the investigators has demonstrated that during pregnancy, the part of the nervous system responsible for cardiovascular function (the sympathetic nervous system) is hyperactive. The investigators also know that in women who develop high blood pressure during pregnancy that sympathetic nervous system activity is even higher. Yet, very little is known about why this occurs and how this might be affected.
Pregnant women are encouraged to be active, yet, less than 15% of women perform sufficient exercise to meet current guidelines. This is important because hyperactivity of the sympathetic nervous system is observed in other inactive populations and has been linked to adverse cardiovascular health outcomes including hypertension, atherosclerosis, heart attack, and stroke. Indeed, in 2011, the American Heart Association stated that inactivity was a risk factor as potent as cigarette smoking for the development of future cardiovascular disease in women.
The investigators' work and others have demonstrated that exercise during pregnancy is beneficial for both the mom and baby; however, the effect of prenatal exercise on neurovascular function is not known. If exercise is effective in controlling the increase in sympathetic activity that occurs during pregnancy, or its effects on the cardiovascular system, this may help prevent the development of high blood pressure or other cardiovascular problems during pregnancy.
详细描述
The objectives of this study are to: 1) examine the impact of exercise on sympathetic and vascular function during pregnancy; 2) examine the role of endothelial function on the vascular effects of exercise during pregnancy.
Study design:
100 women (>18yrs) will be recruited in the first or second trimester (<20 wks). Women with multiple pregnancies will be excluded. Eligible women will be randomized between an aerobic exercise intervention (EXER) or no intervention (CTRL).
Initial testing will take place between 16-20 weeks of pregnancy. Following initial baseline testing, women will be randomly assigned to an exercise intervention or no intervention. Women will receive an opaque sequentially numbered envelop with their allocation. Allocation will be determined using a randomly generated allocation sequence by an individual not associated with the research study. The intervention will consist of aerobic exercise equivalent to 50-70% of heart rate reserve, 3-4 times per week until the end of the study (34-36 weeks). For initial baseline testing (16-20 weeks) and at the end of the intervention (34-36 weeks), participants will visit the laboratory twice
On Day 1, participants will complete a peak exercise test on the treadmill or bike to volitional fatigue to measures fitness and cardiovascular/cerebrovascular responses to exercise.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •>18 years old
- •singleton pregnancy
- •cleared to exercise by health care provider using Par Med X for Pregnancy (CSEP)
排除标准
- •multiple gestation
- •absolute contraindication to exercise (CSEP)
- •<18 years old
- •develops any contraindication during intervention
研究组 & 干预措施
Exercise Intervention
The aerobic exercise intervention will consist of a walking program at 50-70% of individual heart rate reserve. This will begin at 16-20 weeks gestation and continue 3-4 times per week until the end of the study (34-36 weeks). The duration of exercise will increase each week up to a maximum of 40 minutes (5 min warm up, 25 minutes exercise, 5 min cool down). Women will have at least one supervised exercise session per week. The investigators will also monitor other activity using questionnaires and accelerometry. This will occur at baseline (16-20 weeks), mid-intervention (24-26 weeks) and at the end (34-36 weeks).
干预措施: Aerobic exercise (Other)
Control Group
These women will continue regular daily activities. Activity will be monitored periodically with questionnaires and accelerometry. This will occur at baseline (16-20 weeks), mid-intervention (24-26 weeks) and at the end (34-36 weeks).
结局指标
主要结局
Sympathetic Nerve Activity - cold pressor test response
时间窗: 16-20 weeks and 34-36 weeks gestation
Response of the sympathetic nervous system to cold pressor test (% change in activity)
次要结局
- Sympathetic Nerve Activity - breath hold response(16-20 weeks and 34-36 weeks gestation)
- Cerebral blood flow during exercise(16-20 weeks and 34-36 weeks gestation)
- fasted blood sample - blood volume(16-20 weeks and 34-36 weeks gestation)
- fasted blood sample- epigenetics(16-20 weeks and 34-36 weeks gestation)
- Cerebral blood flow at rest(16-20 weeks and 34-36 weeks gestation)
- Respiratory measures - respiratory frequency(16-20 weeks and 34-36 weeks gestation)
- Respiratory measures - lung volume(16-20 weeks and 34-36 weeks gestation)
- Cerebral autoregulation(16-20 weeks and 34-36 weeks gestation)
- fasted blood sample- inflammatory markers(16-20 weeks and 34-36 weeks gestation)
- fasted blood sample- metabolic(16-20 weeks and 34-36 weeks gestation)
- fetal outcomes- NICU(within one month postpartum)
- Endothelial Function- flow mediated dilation(16-20 weeks and 34-36 weeks gestation)
- Respiratory measures - tidal volume(16-20 weeks and 34-36 weeks gestation)
- Respiratory measures - oxygen(16-20 weeks and 34-36 weeks gestation)
- fetal outcomes- birth weight(within one month postpartum)
- Respiratory measures - carbon dioxide(16-20 weeks and 34-36 weeks gestation)
- fasted blood sample - neurotransmitters(16-20 weeks and 34-36 weeks gestation)
- fasted blood sample- sex hormones(16-20 weeks and 34-36 weeks gestation)
- fetal outcomes- length(within one month postpartum)
- fetal outcomes- gestational age(within one month postpartum)
- maternal outcomes- mode of delivery(within one month postpartum)
- maternal outcomes- delivery complications(within one month postpartum)
- maternal outcomes- gestational weight gain(within one month postpartum)
- Endothelial Function - time to peak dilation(16-20 weeks and 34-36 weeks gestation)
- Food log(16-20 weeks and 34-36 weeks gestation)
- maternal outcomes- pregnancy complications(any time during study)
- Depression rating(16-20 weeks and 34-36 weeks gestation)
- fetal outcomes- apgar score(within one month postpartum)
- Endothelial Function - shear stress(16-20 weeks and 34-36 weeks gestation)
- Accelerometry(16-20 weeks and 34-36 weeks gestation)
- Physical Activity Questionnaire(16-20 weeks and 34-36 weeks gestation)
- Sleep Quality(16-20 weeks and 34-36 weeks gestation)