Frandsen Jacob, Pistoljevic Nina, Quesada Julia Prats, Amaro-Gahete Francisco José, Ritz Christian, Larsen Steen, Dela Flemming, Helge Jørn W
Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Department of Physiology, University of Granada, Granada, Spain.
J Appl Physiol (1985). 2020 Mar 1;128(3):681-687. doi: 10.1152/japplphysiol.00774.2019. Epub 2020 Feb 20.
Female sex hormones fluctuate in a predictable manner throughout the menstrual cycle in eumenorrheic women. In studies conducted in both animal and humans, estrogen and progesterone have been found to exert individual metabolic effects during both rest and exercise, suggesting that estrogen may cause an increase in fat oxidation during exercise. However, not all studies find these metabolic changes with the natural physiological variation in the sex hormones. To date, no studies have investigated whether whole body peak fat oxidation rate (PFO) and maximal fat oxidation intensity (FAT) are affected at different time points [mid-follicular (MF), late-follicular (LF), and mid-luteal (ML)] in the menstrual cycle, where plasma estrogen and progesterone are either at their minimum or maximum. We hypothesized that an increased plasma estrogen concentration together with low progesterone concentration in LF would result in a modest but significant increase in PFO. We found no differences in body weight, body composition, or peak oxygen uptake (V̇o) between any of the menstrual phases in the 19 healthy, young eumenorrheic women included in this study. PFO [MF: 0.379 (0.324-0.433) g/min; LF: 0.375 (0.329-0.421) g/min; ML: 0.382 (0.337-0.442) g/min; mean ± (95% CI)] and resting plasma free fatty acid concentrations [MF: 392 (293-492) µmol/l; LF: 477 (324-631) µmol/l; ML: 396 (285-508) µmol/L] were also similar across the menstrual cycle phases. Contrary to our hypothesis, we conclude that the naturally occurring fluctuations in the sex hormones estrogen and progesterone do not affect the whole body PFO and FAT in young eumenorrheic women measured during a graded exercise test. Menstrual cycle phase does not affect the peak fat oxidation rate during a graded exercise test. Natural physiological fluctuations in estrogen do not increase peak fat oxidation rate. FAT is not influenced by menstrual cycle phase in healthy, young eumenorrheic women.
在月经周期正常的女性中，女性性激素会以可预测的方式波动。在针对动物和人类的研究中，已发现雌激素和孕激素在休息和运动期间都会产生各自的代谢影响，这表明雌激素可能会导致运动期间脂肪氧化增加。然而，并非所有研究都发现性激素的自然生理变化会带来这些代谢变化。迄今为止，尚无研究调查在月经周期的不同时间点[卵泡中期（MF）、卵泡晚期（LF）和黄体中期（ML）]，当血浆雌激素和孕激素处于最低或最高水平时，全身峰值脂肪氧化率（PFO）和最大脂肪氧化强度（FAT）是否会受到影响。我们假设，在卵泡晚期，血浆雌激素浓度升高且孕激素浓度较低会导致PFO适度但显著增加。在本研究纳入的19名健康、年轻且月经周期正常的女性中，我们发现任何月经周期阶段之间的体重、身体成分或峰值摄氧量（V̇o）均无差异。PFO[MF：0.379（0.324 - 0.433）克/分钟；LF：0.375（0.329 - 0.421）克/分钟；ML：0.382（0.337 - 0.442）克/分钟；平均值±（95%置信区间）]以及静息血浆游离脂肪酸浓度[MF：392（293 - 492）微摩尔/升；LF：477（324 - 631）微摩尔/升；ML：396（285 - 508）微摩尔/升]在月经周期各阶段也相似。与我们的假设相反，我们得出结论，在分级运动测试期间测量时，雌激素和孕激素的自然波动不会影响年轻月经周期正常女性的全身PFO和FAT。月经周期阶段不会影响分级运动测试期间的峰值脂肪氧化率。雌激素的自然生理波动不会增加峰值脂肪氧化率。在健康、年轻的月经周期正常女性中，FAT不受月经周期阶段的影响。
