Effect Of Menstrual Phase Research Articles

Influence of Menstrual Phase and Symptoms on Sleep Before and After Matches for Professional Footballers.

This study investigated the association of menstrual cycle phase and symptoms with objective and subjective sleep measures from professional footballers before and after matches. Twenty-three non-hormonal contraceptive-using professional footballers (from four clubs) were monitored for up to four menstrual cycles during a domestic league season. Menstrual phases (menstruation, mid-late follicular, luteal) were determined using calendar counting and urinary hormone tests (luteinizing hormone and pregnandiol-3-glucuronide). Players rated the severity of 18 symptoms on the evenings of matches and the following two evenings. Individual daily summed menstrual symptom severity (MSS) scores were calculated. Subjective sleep quality was rated the morning of matches and the following two mornings. Objective sleep (bedtime, waketime, total sleep time [TST], sleep onset latency, wake after sleep onset, sleep efficiency) obtained from actigraphy was measured the night prior to (MN-1), of (MN), and following (MN+1) matches. Linear mixed models were performed for each sleep measure to examine the effects of menstrual phase and symptoms. Bedtime was significantly later for MN (p < 0.001), waketime was significantly earlier for MN+1 (p < 0.001), and TST was significantly longer for MN-1 (p < 0.001). Menstrual phase did not have a significant effect on any sleep variable (p > 0.05). Increased MSS score was associated with increased TST (p = 0.03) and increased waketime (p = 0.03). Increased lower back pain severity and mood changes/anxiety severity were associated with increased waketime (p = 0.048) and TST (p = 0.009), respectively. Overall, bedtime and waketime were affected by the night related to matches, with increased TST the night before a match. Menstrual phase was not related to any objective or subjective sleep variables, whilst increasing menstrual symptom severity was related to later waketime and longer TST.

Influence of Oestradiol Fluctuations in the Menstrual Cycle on Respiratory Exchange Ratio at Different Exercise Intensities: A Systematic Review, Meta-Analysis and Pooled-Data Analysis

Background: Oestradiol has been implicated as a factor in substrate utilisation in male and mouse studies but the effect of acute changes during the menstrual cycle is yet to be fully understood. Objective: To determine the role of oestradiol in respiratory exchange ratio (RER) during exercise at various intensities. Methods: This systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. From inception to November 2023, four online databases (Cochrane, SPORTDiscus, MEDline and Web of Science) were searched for relevant articles. Studies that reported a resting oestradiol measurement in naturally menstruating women with exercise at a percentage of maximal aerobic capacity (%V˙O2max) were included. Mean and standard deviation for oestradiol, RER and exercise intensity were extracted and study quality assessed using a modified Downs and Black checklist. Risk of bias was assessed using I2 measure of heterogeneity and Egger’s regression test, assessment of bias from methodological quality was identified by sensitivity analysis. Eligible datasets were extracted for pairwise comparisons within a meta-analysis and correlation between change in oestradiol and change in RER. Data were also pooled to produce a mean and standard deviation for RER for menstrual stage and for low and high oestradiol groups. Results: Twenty-four articles were identified, over 50% were identified as high quality. Sixteen articles included datasets eligible for meta-analysis. Eleven articles utilised a submaximal constant-load exercise intensity, finding a standardised mean difference of − 0.09 ([CI: −0.35–0.17], p = 0.5) suggesting no effect of menstrual phase on constant-load exercise RER. In six articles using incremental exercise tests to exhaustion, a standardised mean difference of 0.60 ([CI 0.00–1.19], p = 0.05) was identified towards a higher maximal RER attained in follicular compared to luteal phase. There was no correlation (R = −0.26, p = 0.2) between change in oestradiol and change in RER between phases. All 24 articles, totalling 650 participants, were included in pooled analysis. When grouped by menstrual cycle phase or when grouped by oestradiol levels, RER was higher in the follicular phase than the luteal phase at low and high constant load exercise intensities. Discussion: Findings from the pooled-analysis and meta-analysis suggest that there may be menstrual cycle phase differences in RER that are intensity dependent. These differences may be related to sex hormone levels, but this was not supported by evidence of correlation between differences in RER and differences in oestradiol. At present, it remains best practice to assess performance in the same menstrual cycle phase if seeking to assess change from baseline.

Influence of Menstrual Phase and Symptoms on Match Running in Professional Footballers.

This study examined the effects of menstrual cycle phases and symptoms on match running performance in football (soccer) players. Twenty-one nonhormonal contraceptive using football players from four professional teams were monitored for up to four menstrual cycles during a domestic league season. Menstrual phases, classified as early-follicular phase (EFP), mid-late follicular phase (MFP), and luteal phase (LP), were determined by self-reporting of menstruation and urinary hormone tests (luteinizing hormone and pregnanediol-3-glucuronide). On match day, players completed a menstrual symptom severity questionnaire. In repeated matches, players wore 10 Hz Global Positioning Satellite (GPS) devices to measure relative (/min) total distance, high-speed running distance, very high-speed distance, peak speed, acceleration count, and deceleration count. Linear mixed models were performed for each GPS measure to determine the relationship with phase or symptoms. Data for 7 and 10 players were included for menstrual phase and menstrual symptoms analyses, respectively. A significantly higher total distance was reported during MFP compared to EFP (Δ 5.1 m min-1; p = 0.04) and LP (Δ 5.8 m min-1; p = 0.007). Significantly greater high-speed running was reported during MFP compared to EFP (Δ 1.2 m min-1; p = 0.012) and LP (Δ 1.1 m min-1; p = 0.007). No significant effect of menstrual phase was found for any other GPS measures (p > 0.05). Accelerations declined with increasing symptom severity (p = 0.021, estimate = -0.01count.min-1). Menstrual symptom severity did not affect any other GPS measures (p > 0.05). In conclusion, greater total distance and high-speed running occurred during the MFP. Additionally, accelerations minimally decreased with increasing menstrual symptom severity. Large intra- and inter-variability existed, suggesting individualized monitoring and management of menstrual effects on performance would be beneficial.

Effects of menstrual cycle on hemodynamic and autonomic responses to central hypovolemia.

Estrogen and progesterone levels undergo changes throughout the menstrual cycle. Existing literature regarding the effect of menstrual phases on cardiovascular and autonomic regulation during central hypovolemia is contradictory. This study aims to explore the influence of menstrual phases on cardiovascular and autonomic responses in both resting and during the central hypovolemia induced by lower body negative pressure (LBNP). This is a companion paper, in which data across the menstrual phases from healthy young females, whose results are reported in Shankwar et al. (2023), were further analysed. The study protocol consisted of three phases: (1) 30 min of supine rest; (2) 16 min of four LBNP levels; and (3) 5 min of supine recovery. Hemodynamic and autonomic responses (assessed via heart rate variability, HRV) were measured before-, during-, and after-LBNP application using Task Force Monitor® (CNSystems, Graz, Austria). Blood was also collected to measure estrogen and progesterone levels. In this companion paper, we have exclusively assessed 14 females from the previous study (Shankwar et al., 2023): 8 in the follicular phase of the menstrual cycle (mean age 23.38 ± 3.58 years, height 166.00 ± 5.78 cm, weight 57.63 ± 5.39 kg and BMI of 20.92 ± 1.96 25 kg/m2) and 6 in the luteal phase (mean age 22.17 ± 1.33 years, height 169.83 ± 5.53 cm, weight 62.00 ± 7.54 kg and BMI of 21.45 ± 2.63 kg/m2). Baseline estrogen levels were significantly different from the follicular phase as compared to the luteal phase: (33.59 pg/ml, 108.02 pg/ml, respectively, p < 0.01). Resting hemodynamic variables showed no difference across the menstrual phases. However, females in the follicular phase showed significantly lower resting values of low-frequency (LF) band power (41.38 ± 11.75 n.u. and 58.47 ± 14.37 n.u., p = 0.01), but higher resting values of high frequency (HF) band power (58.62 ± 11.75 n.u. and 41.53 ± 14.37 n.u., p = 0.01), as compared to females in the luteal phase. During hypovolemia, the LF and HF band powers changed only in the follicular phase F(1, 7) = 77.34, p < 0.0001 and F(1, 7) = 520.06, p < 0.0001, respectively. The menstrual phase had an influence on resting autonomic variables, with higher sympathetic activity being observed during the luteal phase. Central hypovolemia leads to increased cardiovascular and autonomic responses, particularly during the luteal phase of the menstrual cycle, likely due to higher estrogen levels and increased sympathetic activity.

A pilot study of light exposure as a countermeasure for menstrual phase-dependent neurobehavioral performance impairment in women

ObjectiveTo examine effects of menstrual phase and nighttime light exposure on subjective sleepiness and auditory Psychomotor Vigilance Task performance. MethodsTwenty-nine premenopausal women (12 =Follicular; 17 =Luteal) completed a 6.5-hour nighttime monochromatic light exposure with varying wavelengths (420-620 nm) and irradiances (1.03-14.12 µW/cm2). Subjective sleepiness, reaction time, and attentional lapses were compared between menstrual phases in women with minimal (<33%) or substantial (≥33%) light-induced melatonin suppression. ResultsWhen melatonin was not suppressed, women in the follicular phase had significantly worse reaction time (mean difference=145.1 ms, 95% CI 51.8-238.3, p < .001, Cohen’s D=1.9) and lapses (mean difference=12.9 lapses, 95% CI 4.37-21.41, p < .001, Cohen’s D=1.7) compared to women in the luteal phase. When melatonin was suppressed, women in the follicular phase had significantly better reaction time (mean difference=152.1 ms, 95% CI 43.88-260.3, p < .001, Cohen’s D=1.7) and lapses (mean difference=12.3 lapses, 95% CI 1.14-25.6, p < .01, Cohen’s D=1.6) compared to when melatonin was not suppressed, such that their performance was not different (p > .9) from women in the luteal phase. Subjective sleepiness did not differ by menstrual phase (mean difference=0.6, p > .08) or melatonin suppression (mean difference=0.2, p > .4). ConclusionsNighttime light exposure sufficient to suppress melatonin can also mitigate neurobehavioral performance deficits associated with the follicular phase. Despite the relatively small sample size, these data suggest that nighttime light may be a valuable strategy to help reduce errors and accidents in female shift workers.

0120 Menstrual Cycle-Related Changes in Sleep-Dependent Emotional Memory Consolidation

Abstract Introduction Emotional, more than neutral, experiences are preferentially consolidated during sleep. Fluctuating reproductive hormonal levels across the menstrual cycle are associated with changes in sleep features that are implicated in emotional memory consolidation. Yet, the interaction between menstrual cycle phases, sleep, and emotional memory remains unknown. The current study investigates how sleep-dependent emotional memory consolidation changes across the menstrual cycle in both young and midlife women. Methods Thirty-one young (MAge=25.32y, SD=5.69y) and 33 midlife (MAge=47.88y, SD=2.86y) women enrolled in the study. Each woman completed four remote visits at different menstrual phases, estimated from self-reports and measured ovulation: menses (low hormone), late-follicular (high estrogen), mid-luteal (high estrogen and progesterone), and late-luteal (falling hormones). During each visit, participants completed the Emotional Picture Task (EPT) via Pavlovia, a web-based testing platform. Participants completed encoding and immediate test in the evening (Test 1) and retested (Test 2) the following morning. During encoding, participants viewed negative and neutral images (selected from the IAPS). During testing, for each image, participants reported if it was old or new, and rated the arousal (low to high) and valence (neutral to negative). We measured dPrime at each test and calculated a difference score for overnight memory improvement. Sleep was recorded using Oura ring, a multi-sensor wearable sleep tracker. Mixed linear models determined the effect of menstrual phase on EPT, with visit as a covariate, and relevant sleep features. Results Irrespective of age, menstrual cycle phase (p&amp;lt;0.05) predicted overnight dPrime change score for negative images. Specifically, memory improvement was the highest during mid-luteal, while menses showed the most forgetting. In addition, longer time in bed was associated with less forgetting (p&amp;lt;0.01). These effects were not observed for neutral images (ps&amp;gt;0.05). Conclusion Menstrual phases are characterized by specific sex hormone profiles that can interact with both memory and sleep. The current findings indicate that sleep-dependent memory may also be affected by these changes, specifically memories that have negative emotionally content are more resilient to forgetting during the midluteal phase when both estrogen and progesterone are highest. Future studies (e.g., sleep manipulation) are required to reveal the specific sleep features associated with these effects. Support (If Any) RF1AG061355 (Baker/Mednick)

Pain Across the Menstrual Cycle: Considerations of Hydration

Chronic pain – pain that persists for more than 3 months – is a global health problem and is associated with tremendous social and economic cost. Yet, current pain treatments are often ineffective, as pain is complex and influenced by numerous factors. Hypohydration was recently shown to increase ratings of pain in men, but studies in this area are limited (n = 3). Moreover, whether hypohydration also affects pain in women has not been examined. In women, changes in the concentrations of reproductive hormones across menstrual phases may affect pain, as well as the regulation of body water. This indicates potential interactions between the menstrual phase and hypohydration on pain, but this hypothesis has yet to be tested. This review examined the literature concerning the effects of the menstrual phase and hypohydration on pain, to explore how these factors may interact to influence pain. Future research investigating the combined effects of hypohydration and menstrual phase on pain is warranted, as the findings could have important implications for the treatment of pain in women, interpretation of previous research and the design of future studies.

Menstrual Phase Affects Coagulation and Hematological Parameters during Central Hypovolemia.

Background: It has been reported that women have a higher number of heart attacks in the “follicular phase” of the menstrual cycle. We, therefore, tested the hypothesis that women in the follicular phase exhibit higher coagulability. As lower body negative pressure (LBNP) has been used previously to assess coagulation changes in whole blood (WB) samples in men and women, effects of menstrual phase on coagulation was assessed during LBNP. Methods: Seven women, all healthy young participants, with no histories of thrombotic disorders and not on medications, were tested in two phases of the menstrual cycle (early follicular (EF) and mid-luteal (ML)). LBNP was commenced at −10 mmHg and increased by −10 mmHg every 5 min until a maximum of −40 mmHg. Recovery up to 10 min was also monitored. Blood samples were collected at baseline, at end of LBNP, and at end of recovery. Hemostatic profiling included comparing the effects of LBNP on coagulation values in both phases of the menstrual cycle using standard coagulation tests, calibrated automated thrombogram, thrombelastometry, impedance aggregometry, and markers of thrombin formation. Results: LBNP led to coagulation activation determined in both plasma and WB samples. During both phases, coagulation was affected during LBNP, as reflected in their decreased partial thromboplastin time (PTT) and elevated coagulation factor VIII FVIII, F1 + 2, and thrombin-antithrombin (TAT) levels. Additionally, during the ML phase, greater PT [%] and shorter time to peak (ttPeak) values (implying faster maximum thrombin formation) suggest that women in the ML phase are relatively hypercoagulable compared to the early follicular phase. Conclusions: These results suggest that thrombosis occurs more during the midluteal phase, a finding with substantial medical implications.

Effect of menstrual cycle on resting metabolism: A systematic review and meta-analysis.

BackgroundThe need to control for the potential influence of menstrual cycle phase on resting metabolism (RMR) places a burden on research participants who must self-report onset of menstruation and researchers who must schedule metabolic testing accordingly.PurposeTo systematically review and analyze existing research to determine the effect of menstrual cycle on RMR.MethodsWe searched PubMed, CINAHL, MEDLINE, SPORTDiscus, and Scopus databases using the search terms “menstrual cycle and metabolic rate” and “menstrual cycle and energy expenditure.” Eligibility criteria were English language, single-group repeated measures design, and RMR as either a primary or secondary outcome. Risk of bias was assessed based on study sample, measurement, and control of confounders. Differences between the follicular and luteal phases of the menstrual cycle were analyzed using the standardized mean difference in effect size.ResultsThirty English-language studies published between 1930 and December 2019 were included in the systematic review, and 26 studies involving 318 women were included in the meta-analysis. Overall, there was a small but significant effect favoring increased RMR in the luteal phase (ES = 0.33; 95% CI = 0.17, 0.49, p < 0.001).DiscussionLimitations include risk of bias regarding measurement of both menstrual cycle and RMR. Sample sizes were small and studies did not report control of potential confounders. Sub-group analysis demonstrated that in more recent studies published since 2000, the effect of menstrual phase was reduced and not statistically significant (ES = 0.23; 95% CI = -0.00, 0.47; p = 0.055). Until larger and better designed studies are available, based on our current findings, researchers should be aware of the potential confounding influence of the menstrual cycle and control for it by testing consistently in one phase of the cycle when measuring RMR in pre-menopausal women.

Physical, Biochemical, and Neuromuscular Responses to Repeated Sprint Exercise in Eumenorrheic Female Handball Players: Effect of Menstrual Cycle Phases.

Graja, A, Kacem, M, Hammouda, O, Borji, R, Bouzid, MA, Souissi, N, and Rebai, H. Physical, biochemical, and neuromuscular responses to repeated sprint exercise in eumenorrheic female handball players: effect of menstrual cycle phases. J Strength Cond Res 36(8): 2268-2276, 2022-Very few studies have been interested in the relationship between ovarian hormones and physiological function in female athletes. The aim of this study was to assess the effect of menstrual phases (MP) on physical, neuromuscular, and biochemical responses after repeated sprint exercise (RSE) in female handball players. Ten eumenorrheic athletes (22.5 ± 1.5 years, 1.70 ± 0.04 m) participated in 3 study visits (follicular phase [FP], luteal phase [LP], and premenstrual phase [PMP]). During each MP, they performed 20 × 5-second cycle sprints interspersed with 25 seconds of rest. Maximal voluntary contraction (MVC) tests of the knee extensor muscles at 90° of knee flexion were performed before and after RSE. Peak force and electromyography (EMG) signals were measured during the MVC tests. Blood samples were collected before and 3 minutes after each session. The percentage of decrement in peak power output over the 20 × 5-second cycle test (i.e., fatigue index) calculated between sprints 1 and 20 decreased significantly during PMP (-43.3% ± 5.7%) but not in LP (-39.2% ± 7.7%) compared with FP (-32.44% ± 6.3%) ( p < 0.05). Moreover, no significant difference was found between MP in all frequency components of EMG before RSE ( p > 0.05). Maximal voluntary contraction, neuromuscular efficiency, and median frequency values of vastus lateralis and rectus femoris were significantly decreased in PMP compared with FP and LP ( p < 0.05). Creatine kinase (CK) levels were significantly higher in PMP compared with FP and LP after RSE ( p < 0.05). These findings suggest that RSE induces more peripheral fatigue associated with muscle damage in PMP. This might be attributable to hormonal variation across MP. Therefore, FP seems to be the right time for intense training to improve strength performance.

Effect of exogenous progesterone administration on cigarette smoking-related symptomology in oral contraceptive users who smoke

Cigarette smoking-related symptomatology (e.g., craving; SRS) is linked to relapse after a quit attempt. SRS varies by menstrual phase, possibly due to variations in sex hormones (e.g., progesterone), though much of the research to-date has relied on observations from the menstrual cycle acting as a proxy for hormone levels. The goal of this study was to examine the effect of exogenous progesterone on SRS during ad libitum smoking and following overnight abstinence.Oral contraceptive users who smoked completed two 9-day crossover testing periods (7 days of ad libitum smoking and 2 days following overnight abstinence) while taking double-blind active/placebo exogenous progesterone. Participants completed questionnaires to measure SRS. The effect of exogenous progesterone and endogenous hormones (progesterone, estradiol, and progesterone-to-estradiol [P/E2] ratio) on SRS was assessed with paired t-tests and linear mixed effect models.Participants (n = 53) were, on average, 24 years old and smoked 11 cigarettes per day. During ad libitum smoking, a doubling of the P/E2 ratio was associated with 0.09 points lower anticipated relief from negative affect (95% confidence interval [CI]: 0.03–0.15 points lower; p = 0.008) and 0.11 points lower psychological reward (95% CI: 0.03–0.18 points lower; p = 0.006). After correction for multiple testing, these associations were not statistically significant: anticipated relief from negative effect (p = 0.10) and psychological reward (p = 0.09). No other significant associations were observed.Although substantial previous literature indicates that progesterone influences SRS, exogenous progesterone administration did not alter SRS here. Additional research is needed to elucidate alternative mechanisms involved in menstrual phase effects on SRS.

Effect of Menstrual Cycle on Aerodynamic Measures among Singers and Nonsingers

Singer’s vocal apparatus is comprised of her entire body and mind and is easily influenced by hormonal variations. The hormonal changes may have adverse effects on a singer’s vocal performance. There is very little understanding about the aerodynamic measures among singers especially during the different phases of menstrual cycle in Indian population. Aims and objectives: To study the effect of menstrual cycle on aerodynamic measures among singers and nonsingers. The objectives of the study were to profile aerodynamic measures in singers and nonsingers, to compare the aerodynamic measures between the singers and nonsingers, and to study the effect of menstrual phase on aerodynamic measures between singers and nonsingers. Materials and methods: The participants in group I comprised of 30 nonsingers in the age range of 18–25 years. Group II comprised of 15 trained singers (received training formally more than 3 years), and group III had 15 untrained singers in the age range of 18–25 years. The forced vital capacity (FVC), forced expiratory volume in first second (FEVl), and peak expiratory airflow (PEF) were recorded. Descriptive statistics and repeated measure of ANOVA were done to study the effect of menstrual cycle on aerodynamic measures among singers and nonsingers using SPSS 16.0. Results: In the present study, the overall mean scores obtained for all the aerodynamic measures were reduced during menstrual phase as compared to the aerodynamic measures obtained during the follicular phase among both singers and nonsingers.

SAT-207 The Effects of the Menstrual Cycle and Caloric Restriction on Sleep in Young Women

Background: Dynamic changes in reproductive hormone levels across the menstrual cycle have been hypothesized to disrupt normal sleep patterns. While some studies reported increased sleep disruption in the luteal phase, others did not. In addition, metabolic hormones including ghrelin and cortisol are linked to both sleep regulation and the reproductive axis. However, studies have focused on the responses of these hormones to sleep, rather than their effects on sleep. The purpose of this study was to evaluate the effects of hormonal changes across the menstrual cycle and decreased energy availability on Actigraphy-defined objective sleep measures in an in-home setting in young, regularly-cycling women. Methods: As a part of a larger study, reproductive hormones were collected from 10 healthy, regularly-cycling women aged 18-28 years over the course of two menstrual cycles. Daily Actigraphic sleep data (n=578 sleep episodes) and urinary concentrations of LH, estrone-3-glucuronide (E1G), and pregnanediol-3-glucuronide (PDG) were collected. Subjects completed two 5-day diet interventions (neutral versus decreased energy availability) during the early follicular phases (EFP) of separate cycles. Cycles were centered on day of ovulation and standardized to 14-day follicular and 14-day luteal phases. Sleep data were analyzed using linear mixed models by menstrual phase, diet interventions, and reproductive hormones, adjusting for weekday vs weekend. Results: Hormonal measurements confirmed ovulation in both cycles in all subjects (age 24.5 ± 2.5, BMI 22.2 ± 2.1). There was an effect of menstrual phase on sleep efficiency (SE, p=0.005), wake after sleep onset (WASO, p=0.04), number of awakenings per night (p=0.02), and sleep fragmentation index (SFI, p=0.06), consistent with increased sleep disruption in the late luteal phase (LLP). In comparison with the EFP, SE decreased by 3.3% (p=0.0002), WASO increased by 15 minutes (p=0.001), and number of awakenings increased by 3 (p=0.04) in the LLP. Decreased energy availability increased sleep disruption, as indicated by decreased SE (p<0.05), increased WASO (p=0.03), and increased SFI (p=0.07). With decreased energy availability, post-hoc analyses showed increased sleep disruption in both the late follicular phase (LFP) and LLP. E1G was associated with an increase in number of awakenings (p=0.007), such that an increase of E1G by 50 mcg/g Cr increased the number of awakenings by 2.4. PDG was associated with a trend toward increased SFI (p=0.07). Conclusions: Among healthy, young women, objective sleep varies across the menstrual cycle, marked by decreased SE, increased WASO, and increased number and duration of awakenings in the LLP. In addition, decreased energy availability in the EFP increases sleep disruption, with greatest effects in the LFP and LLP.

Effects of Caffeine and Menstrual Phase on Performance of Female Athletes during Heat Stress

The effects of menstrual phase on athletic performance are controversial, but commonly ascribed to temperature‐related impairments in physical and cognitive performances. Caffeine stimulates the CNS to enhance endurance performance, and while effects persist for men exercising in the heat, little work has been done with women. Moreover, many female athletes use oral contraceptive steroids (OCS) to regulate their menstrual cycles, which may pronounce the effects of caffeine. The purpose of this study was to evaluate the effects of menstrual phase and caffeine supplementation on physical and cognitive performances of women exercising in the heat. Six recreationally active female subjects (20.3 ± 1.6 yr, 1.67 ± 0.05 m, 69.3 ± 5.5 kg, 49.8 ± 3.3 ml·kg−1·min−1) concurrently taking monophasic OCS volunteered for this study. Each subject completed four trials: in the early follicular (EF, days 3–5) and midfollicuar (MF, days 19–21) phases of the menstrual cycle, after administration of either a placebo (P, corn starch) or caffeine (C, 5.5 mg/kg). Placebo and caffeine were administered in 355 mL “diet” cranberry drink (0 kcal), 1 hour prior to performing a self‐paced 5km time trial (TT) in the heat (29.6 ± 0.1°C, 55.8 ± 1.5 % relative humidity). Heart rate was recorded continuously and RPE was collected at 1‐km intervals. Oral temperature, Profile of Mood States (POMS) questionnaires and 2 tests of reaction and cognition (FitLight) were performed immediately prior to and following exercise. Time trial performance was improved in the EF‐C trial vs. EF‐P, ML‐C and ML‐P (1883 ± 203 vs. 1918 ± 224, 1898 ± 196, 1907 ± 205 seconds). Oral temperature tended to be elevated post‐TT in EF‐C vs. all other trials (37.4 vs. ~37.0 °C), while HR AUC tended to be decreased in the EF trials (5404 ± 167 vs. 5544 ± 181 beats, p = 0.09). The POMS Fatigue index was significantly higher post‐TT in the ML‐C trial (15.0 ± 1.9 vs 12.7 ± 0.4, 10.8 ± 1.1, ±11.2 ± 1.0). RPE and cognitive test responses were not different between trials. In heat stress, caffeine improves time trial performance in the EF phase despite an increased post‐exercise oral temperature. While heart rate response tended to be lower in the EF phase, no differences were observed in any other physical or cognitive performance measure between trials.Support or Funding InformationScotia Scholars Award, Nova Scotia Health Research FoundationThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Differences in mood and cortisol by menstrual phase during acute smoking abstinence: A within-subject comparison.

There is evidence that smoking-cessation success differs by menstrual phase and sex hormone levels; however, the biological mechanisms underlying these differences are not clear. One possibility is that variation in cortisol throughout the menstrual cycle and early smoking abstinence may be partly responsible. The goal of this secondary-data analysis was to conduct a within-subject examination of the effects of menstrual phase and smoking abstinence on salivary cortisol and mood. Data are from a controlled crossover trial, in which participants completed 2 testing weeks during their follicular and luteal phases. During each testing week, they smoked ad libitum during the first 2 days and then abstained from smoking during the next 4 days. Salivary cortisol and self-reported mood were collected 5 times on the day before abstinence (D0) and the first (D1) and third (D3) days of abstinence. Participants (n = 125) were, on average (mean ± SE), 29.4 ± 0.6 years old and smoked 12.6 ± 0.5 cigarettes/day. Whereas salivary cortisol varied significantly by time of day (p < .0001) and smoking abstinence (D0 to D1: β = -0.06 ± 0.02 log[ng/ml], p = .0074 and D3: β = -0.05 ± 0.02 log[ng/ml], p = .0117). no significant differences by menstrual phase were observed. Craving increased from D0 to D1 during the follicular phase but decreased in the luteal phase (+0.31 vs. -0.15, β = 0.46 ± 0.19, p = .0162). This work builds on prior observations in demonstrating a decrease in cortisol in acute smoking abstinence and menstrual phase differences in craving. The results provide further evidence that cortisol levels do not vary by menstrual phase in the first few days of abstinence. (PsycINFO Database Record

The effect of sex and menstrual phase on memory formation during a nap

Memory formation can be influenced by sleep and sex hormones in both men and women, and by the menstrual cycle in women. Though many studies have shown that sleep benefits the consolidation of memories, it is not clear whether this effect differs between men and women in general or according to menstrual phase in women. The present study investigated the effect of sex and menstrual cycle on memory consolidation of face-name associations (FNA) following a daytime nap. Recognition memory was tested using a face-name paired associates task with a polysomnographic nap between morning and evening testing. Seventeen healthy women (age: 20.75 (1.98) years) were studied at two time points of their menstrual cycles, defined from self-report and separated by 2weeks (perimenses: −5days to +6days from the start of menses, and non-perimenses: outside of the perimenses phase), and compared with eighteen healthy men (age: 22.01 (2.91) years). Regardless of menstrual phase, women had better pre-nap performance than men. Further, menstrual phase affected post-nap memory consolidation, with women showing greater forgetting in their perimenses phase compared with their non-perimenses phase and men. Interestingly, post-nap performance correlated with electrophysiological events during sleep (slow oscillations, spindles, and temporal coupling between the two), however, these correlations differed according to menstrual phase and sex. Men’s performance improvement was associated with the temporal coupling of spindles and slow oscillations (i.e., spindle/SO coincidence) as well as spindles. Women, however, showed an association with slow oscillations during non-perimenses, whereas when they were in their perimenses phase of their cycle, women appeared to show an association only with sleep spindle events for consolidation. These findings add to the growing literature demonstrating sex and menstrual phase effects on memory formation during sleep.

Oral Contraceptive Pill Alters Acute Dietary Protein-Induced Thermogenesis in Young Women.

There is much interest in the role of dietary protein for weight control. However, there remains a need to characterize individual determinants of the thermogenic effects of protein. This study aimed to investigate the influence of menstrual cycle phase and the combined, monophasic oral contraceptive pill on the thermogenic response to a standardized high-protein (HP) versus normal-protein (NP) meal. Following an overnight fast, resting energy expenditure (EE) was measured in 16 healthy young women (8 taking and 8 not taking the pill) and 8 men for 30 minutes pre ingestion and 3 hours post ingestion of a NP (11%) or HP (24%) meal. There was no effect of menstrual phase or contraceptive pill use on fasting EE or NP response. However, HP increased EE significantly more than NP in women not taking the oral contraceptive pill and in men, but not in women taking the pill. This study shows an absence of the greater thermic effect of HP versus NP in women taking the oral contraceptive pill and has important implications regarding the effectiveness of HP for body weight regulation in women. With current obesity treatment/prevention strategies remaining largely ineffective, understanding the relationship between oral contraceptive pill use and protein-induced thermogenesis may enable the successful recalibration of existing dietary recommendations.

Effect of menstrual phase on the surgical treatment of ovarian cysts

This study aimed to determine whether the menstrual cycle affects operative bleeding and postoperative ovarian reserve in patients undergoing laparoscopic ovarian cystectomy. A total of 155 patients who had undergone laparoscopic ovarian cystectomy were classified into the follicular phase (n = 84) and luteal phase (n = 71) of the menstrual cycle. The primary outcome measures were operative blood loss and the rate of decline in ovarian reserve, as calculated by measuring serial serum anti-Müllerian hormone (AMH) levels preoperatively and 3 months postoperatively. No significant difference in the baseline demographics, operative blood loss (p = .984), the rate of decline in ovarian reserve (p = .945), and other surgical outcomes were observed between both the groups. These results demonstrate that the menstrual cycle had no influence on the operative blood loss and ovarian reserve during laparoscopic ovarian cystectomy. Therefore, the menstrual cycle is not an important factor to determine the optimal timing of ovarian cystectomy.Impact statementWhat is already known on this subject?: The menstrual cycle results in periodic changes in haemostasis and blood flow in the reproductive organs.What do the results of this study add?: These results demonstrate that the menstrual cycle had no influence on the operative blood loss and ovarian reserve during laparoscopic ovarian cystectomy.What are the implications of these findings for clinical practice and/or further research?: The menstrual cycle is not an important factor to determine the optimal timing of ovarian cystectomy.

The effects of menstrual phase on orthodontic pain following initial archwire engagement.

To explore the effects of menstrual cycle on orthodontic pain following initial archwire engagement. Female participants with regular menstrual cycles were recruited and assigned into follicular group or luteal group. Demographical and baseline variables were collected: age, education, menstrual duration, anxiety, oral health impact profile-14 (OHIP-14), and index of complexity outcome and need (ICON). Following initial archwire engagement, orthodontic pain was determined through visual analogue scale (VAS) on 1st day, 2nd day, and 3rd day. Demographical and baseline variables were compared between the two groups. Two-way repeated-measures anova was used to examine the effects of menstrual phase, time, and their interactions on orthodontic pain. Multivariate linear regression was employed to examine the independent effect of each variable on orthodontic pain. Finally, 37 and 39 were assigned to the follicular and luteal groups, respectively, with balanced demographical and baseline data. Orthodontic pain was significantly affected by menstrual phase and time (both P<0.001), but there was no interaction (P>0.05). Moreover, orthodontic pain was independently predicted by menstrual phase, OHIP, education level, and anxiety (all P<0.05). We suggest that practitioners arrange female patients to receive initial archwire engagement during their follicular phases to relieve orthodontic pain.

The Effects of the Menstrual Cycle on Vibratory Characteristics of the Vocal Folds Investigated With High-Speed Digital Imaging

This study investigated the effect of menstrual cycle on vocal fold vibratory characteristics in young women using high-speed digital imaging. This study examined the menstrual phase effect on five objective high-speed imaging parameters and two self-rated perceptual parameters. The effects of oral birth control use were also investigated. Thirteen subjects with no prior voice complaints were included in this study. All data were collected at three different time periods (premenses, postmenses, ovulation) over the course of one menstrual cycle. For five of the 13 subjects, data were collected for two consecutive cycles. Six of 13 subjects were oral birth control users. From high-speed imaging data, five objective parameters were computed: fundamental frequency, fundamental frequency deviation, harmonics-to-noise ratio, harmonic richness factor, and ratio of first and second harmonics. They were supplemented by two self-rated parameters: Reflux Severity Index and perceptual voice quality rating. Analysis included mixed model linear analysis with repeated measures. Results indicated no significant main effects for menstrual phase, between-cycle, or birth control use in the analysis for mean fundamental frequency, fundamental frequency deviation, harmonics-to-noise ratio, harmonic richness factor, first and second harmonics, Reflux Severity Index, and perceptual voice quality rating. Additionally, there were no interaction effects. Hormone fluctuations observed across the menstrual cycle do not appear to have direct effect on vocal fold vibratory characteristics in young women with no voice concerns. Birth control use, on the other hand, may have influence on spectral richness of vocal fold vibration.