Effects of Oral Contraceptive Consumption Timing on Cognition and Metabolism
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 16
- 试验地点
- 1
- 主要终点
- Verbal Fluency
研究概览
简要总结
The aim of this randomised-controlled trial is to examine whether the timing of oral contraceptive administration affects cognitive function, substrate metabolism and exercise performance.
Participants will attend the laboratory for a familiarisation session, followed by two main trials in which cognition and exercise metabolism and performance are measured. In one trial they will be given their oral contraceptive 60 minutes before testing begins, in the other they will be given a placebo. Following testing (~60 minutes), participants will consume the alternative pill.
详细描述
Reproductive hormones, such as oestrogen and progesterone, are known to affect cognitive function (i.e. thinking, learning and processing information) and substrate metabolism (i.e. how the body uses carbohydrates and fats). Oral contraceptives contain synthetic versions of reproductive hormones and are used by approximately half of women of reproductive age. When oral contraceptives are ingested, the concentrations of these synthetic hormones spike in the blood for several hours, yet no research has explored the effect of this spike on how the body works, especially with regards to cognitive function and substrate metabolism. If this spike in synthetic hormone concentrations affects cognition or metabolism, this could influence the way in which women use oral contraceptives, such as altering the timing of ingestion to improve performance and health outcomes.
The proposed study will use participants that currently use a specific preparation of oral contraceptive (30micrograms ethinyl estradiol and 150mg Levonorgestrel) and compare cognitive function and substrate metabolism on an occasion when a placebo is consumed (lactose - no hormones), to an occasion when their oral contraceptive is consumed. It takes approximately 60-90 minutes for concentrations of hormones to peak in the blood following ingestion, therefore measurements of cognitive function and substrate metabolism will be taken at this time. Cognitive function will be measured using a battery of tests administered orally or via a laptop and substrate metabolism will be measured by collecting expired air via a mouthpiece at rest and during exercise on a treadmill, during which time perceived difficulty of the exercise (rate of perceived exertion) and feelings (felt arousal) will be measured. Venous blood samples will be drawn at baseline (immediately before consumption of first pill/placebo) and 90 minutes following this. The participants will consume either the placebo or oral contraceptive (whichever was not initially consumed) following the testing protocol to ensure that their contraceptive protection is maintained.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Other
- 盲法
- Double (Participant, Investigator)
盲法说明
Random number generator, via technicians, concealed allocation
入排标准
- 年龄范围
- 18 Years 至 35 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Aged 18-35 years
- •The use of the same oral contraceptive (30 micrograms ethinyl estradiol and 150mg levonorgestrel) for at least 6 months
- •Physically active and able to take part in treadmill-based exercise
- •Speak fluent English
排除标准
- •Use of any other type of hormonal contraception
- •Aged < 18 or > 35 years
- •Poly-cystic ovarian syndrome
- •Endometriosis
- •Child birth or lactation in the previous 6 months
- •Body mass index < 18.5 or > 30 kg.m2
- •Any disorder known to affect metabolic health
- •History of head injury/neurological disorders
- •Use of any steroid-based medication or medications known to influence the central nervous system
- •History of psychiatric disorders such as major depression or an anxiety disorder
- •Suffer from (or have suffered from) a heart complaint
- •Advised by medical professional to refrain from high intensity exercise
- •Current muscle or joint injury
研究组 & 干预措施
Oral contraceptive
Participants existing oral contraceptive to be ingested at 8am on a day between 3 to 21 of pill consumption. Placebo consumed ~2 hours later
干预措施: Combined oral contraceptive pill (Drug)
Placebo
Placebo ingested at 8am on a day between 3 to 21 of pill consumption. Participants existing oral contraceptive consumed ~2 hours later
干预措施: Combined oral contraceptive pill (Drug)
结局指标
主要结局
Verbal Fluency
时间窗: 60-90 minutes post oral contraceptive/placebo ingestion
Words said
Rey Auditory Verbal Test Performance
时间窗: 60-90 minutes post oral contraceptive/placebo ingestion
Acquisition, Learning rate, Proactive Interference, Retroactive interference, Forgetting
Mental Rotation test
时间窗: 60-90 minutes post oral contraceptive/placebo ingestion
Accuracy, Response time
Stroop test
时间窗: 60-90 minutes post oral contraceptive/placebo ingestion
Accuracy, Response time
Corsi blocks
时间窗: 60-90 minutes post oral contraceptive/placebo ingestion
Correct sequences, longest sequence
Feeling scale
时间窗: During final minute of of 6 minutes exercise at both 70 and 90% lactate threshold. Exercise takes place approximately 90 minutes post oral contraceptive/placebo ingestion
Feeling scale -5 to +5. Higher value indicates more positive feeling.
Heart rate
时间窗: During final minute of of 6 minutes exercise at both 70 and 90% lactate threshold. Exercise takes place approximately 90 minutes post oral contraceptive/placebo ingestion
beats per minute
Rapid Visual Information Processing
时间窗: 60-90 minutes post oral contraceptive/placebo ingestion
Proportion correct, Response time
Rating of perceived exertion
时间窗: During final minute of of 6 minutes exercise at both 70 and 90% lactate threshold. Exercise takes place approximately 90 minutes post oral contraceptive/placebo ingestion
Borg rating of perceived exertion (RPE) scale from 6-20. Higher value indicates greater exertion
Felt arousal
时间窗: During final minute of of 6 minutes exercise at both 70 and 90% lactate threshold. Exercise takes place approximately 90 minutes post oral contraceptive/placebo ingestion
Felt arousal scale from 1-6. Higher value indicates greater level of arousal
Maximal oxygen consumption (VO2max)
时间窗: During maximal exercise test which occurs approximately 110 minutes post oral contraceptive/placebo ingestion
Maximal rate of oxygen used
Maximal heart rate
时间窗: During maximal exercise test which occurs approximately 110 minutes post oral contraceptive/placebo ingestion
Maximal heart rate achieved
Carbohydrate oxidation
时间窗: During final minute of of 6 minutes exercise at both 70 and 90% lactate threshold. Exercise takes place approximately 90 minutes post oral contraceptive/placebo ingestion
Rate of carbohydrate use
Respiratory exchange ratio
时间窗: During final minute of of 6 minutes exercise at both 70 and 90% lactate threshold. Exercise takes place approximately 90 minutes post oral contraceptive/placebo ingestion
Ratio of carbohydrate and fat metabolism
Fat oxidation
时间窗: During final minute of of 6 minutes exercise at both 70 and 90% lactate threshold. Exercise takes place approximately 90 minutes post oral contraceptive/placebo ingestion
Rate of fat use
Breathing frequency
时间窗: During final minute of of 6 minutes exercise at both 70 and 90% lactate threshold. Exercise takes place approximately 90 minutes post oral contraceptive/placebo ingestion
breaths per minute
Time to exhaustion
时间窗: During maximal exercise test which occurs approximately 110 minutes post oral contraceptive/placebo ingestion
Time before test termination
次要结局
- Seum ethinyl estradiol(Baseline and immediately post cognitive function tests)
- Serum Levonorgestrel(Baseline and immediately post cognitive function tests)