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Reproductive Biology and Endocrinology... Jan 2023Metformin is the gold standard insulin sensitizer, which is widely used to treat insulin resistance in polycystic ovary syndrome (PCOS). However, metformin may induce... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Metformin is the gold standard insulin sensitizer, which is widely used to treat insulin resistance in polycystic ovary syndrome (PCOS). However, metformin may induce gastrointestinal side effects.
OBJECTIVE
Inositols have long been debated as a potential alternative for metformin in treating PCOS. Therefore, the present systematic review aimed to evaluate the efficacy and safety of inositols in treating PCOS.
METHODS
The present systematic search was performed in CENTRAL, MEDLINE, and Embase from the inception until October 20th, 2021. Eligible randomized controlled trials (RCTs) included women diagnosed with PCOS and compared any inositols with metformin or placebo. Our primary outcome was cycle normalization, whereas secondary outcomes were body mass index (BMI), parameters of carbohydrate metabolism and clinical and laboratory hyperandrogenism. Results are reported as risk ratios or mean differences (MDs) with 95% confidence intervals (CIs).
RESULTS
Twenty-six RCTs were identified, including data of 1691 patients (806 inositol, 311 with placebo, and 509 metformin groups). In patients treated with inositols, the risk (CI: 1.13; 2.85) of having a regular menstrual cycle was found by 1.79 higher than in the case of placebo. Moreover, the inositols showed non-inferiority compared to metformin in this outcome. In the case of BMI (MD = -0.45; CI: -0.89; -0.02), free testosterone (MD = -0,41, CI: -0.69; -0.13), total testosterone (MD = -20.39, CI: -40.12; -0.66), androstenedione (MD = -0.69, CI: -1,16; -0.22), glucose (MD = -3.14; CI: -5.75; -0.54) levels and AUC insulin (MD = -2081.05, CI: -2745.32; -1416.78) inositol treatment induced greater decrease compared to placebo. Inositol increased sex-hormone-binding globulin significantly compared to placebo (MD = 32.06, CI:1.27; 62.85).
CONCLUSION
Inositol is an effective and safe treatment in PCOS. Moreover, inositols showed non-inferiority in most outcomes compared to the gold standard treatment; metformin.
TRIAL REGISTRATION
PROSPERO registration number: CRD42021283275.
Topics: Female; Humans; Polycystic Ovary Syndrome; Inositol; Hypoglycemic Agents; Randomized Controlled Trials as Topic; Metformin; Testosterone; Insulins
PubMed: 36703143
DOI: 10.1186/s12958-023-01055-z -
Sports Medicine (Auckland, N.Z.) Oct 2020Concentrations of endogenous sex hormones fluctuate across the menstrual cycle (MC), which could have implications for exercise performance in women. At present, data... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Concentrations of endogenous sex hormones fluctuate across the menstrual cycle (MC), which could have implications for exercise performance in women. At present, data are conflicting, with no consensus on whether exercise performance is affected by MC phase.
OBJECTIVE
To determine the effects of the MC on exercise performance and provide evidence-based, practical, performance recommendations to eumenorrheic women.
METHODS
This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Four databases were searched for published experimental studies that investigated the effects of the MC on exercise performance, which included at least one outcome measure taken in two or more defined MC phases. All data were meta-analysed using multilevel models grounded in Bayesian principles. The initial meta-analysis pooled pairwise effect sizes comparing exercise performance during the early follicular phase with all other phases (late follicular, ovulation, early luteal, mid-luteal and late luteal) amalgamated. A more comprehensive analysis was then conducted, comparing exercise performance between all phases with direct and indirect pairwise effect sizes through a network meta-analysis. Results from the network meta-analysis were summarised by calculating the Surface Under the Cumulative Ranking curve (SUCRA). Study quality was assessed using a modified Downs and Black checklist and a strategy based on the recommendations of the Grading of Recommendations Assessment Development and Evaluation (GRADE) working group.
RESULTS
Of the 78 included studies, data from 51 studies were eligible for inclusion in the initial pairwise meta-analysis. The three-level hierarchical model indicated a trivial effect for both endurance- and strength-based outcomes, with reduced exercise performance observed in the early follicular phase of the MC, based on the median pooled effect size (ES = - 0.06 [95% credible interval (CrI): - 0.16 to 0.04]). Seventy-three studies had enough data to be included in the network meta-analysis. The largest effect was identified between the early follicular and the late follicular phases of the MC (ES = - 0.14 [95% CrI: - 0.26 to - 0.03]). The lowest SUCRA value, which represents the likelihood that exercise performance is poor, or among the poorest, relative to other MC phases, was obtained for the early follicular phase (30%), with values for all other phases ranging between 53 and 55%. The quality of evidence for this review was classified as "low" (42%).
CONCLUSION
The results from this systematic review and meta-analysis indicate that exercise performance might be trivially reduced during the early follicular phase of the MC, compared to all other phases. Due to the trivial effect size, the large between-study variation and the number of poor-quality studies included in this review, general guidelines on exercise performance across the MC cannot be formed; rather, it is recommended that a personalised approach should be taken based on each individual's response to exercise performance across the MC.
Topics: Athletic Performance; Exercise; Female; Humans; Menstrual Cycle
PubMed: 32661839
DOI: 10.1007/s40279-020-01319-3 -
The Effects of Menstrual Cycle Phase on Elite Athlete Performance: A Critical and Systematic Review.Frontiers in Physiology 2021: In elite athletes, training individualization is widely recommended to optimize competitive performance. Previous studies have evidenced the impact of hormonal... (Review)
Review
: In elite athletes, training individualization is widely recommended to optimize competitive performance. Previous studies have evidenced the impact of hormonal fluctuations on different performance parameters among female athletes. While consideration of menstrual cycle (MC) phases as a parameter in training individualization strategies is necessary, systematic evidence identifying such impacts in elite athletes should be evaluated. : Systematically review publications that have investigated the link between MC phases and performance in elite female athletes. The overarching aim is to identify whether a consensus across studies exists enabling evidence-based recommendations for training individualization depending on menstrual cycle phases. : This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Three major scientific publication databases were searched from inception until November 3, 2020. Studies included focused on the influence of physiological or psychological parameters throughout at least one phase of the menstrual cycle of elite athletes. : A total of 780 search results were yielded and 26 references from a past bibliography were added manually. About 662 papers were reviewed of which 218 studies were assessed for eligibility. Of these, only seven (1%) precisely investigated the influence of a performance or physical parameter during at least one menstrual cycle phase. These seven studies included a total of 314 elite female participants (20.58 ± 1.91 years). Three used interviews, questionnaires or prospective analyses of reports. Four conducted several performance tests or included physical measures although only two performed tests during training or before/during competition. Among the seven studies, five performed hormonal testing through sampling of blood, saliva, or urine. The remaining relied on athletes' menstruation diaries. The current evidence suggests a variable association between menstrual cycle and a few performance-related outcomes, such as endurance or power resistance, ligament stiffness, decision making skills, psychology, or competitiveness. : Different sports performance-related parameters are affected during the menstrual cycle among elite athletes, but the parameters themselves and the magnitude and the direction of the effects are inconclusive. Additional longitudinal and prospective studies to systematically monitor on-field performance parameters are urgently required in order to enable recommendations and training individualization in female elite athletes.
PubMed: 34093223
DOI: 10.3389/fphys.2021.654585 -
International Journal of Environmental... Feb 2023The presence of female athletes has only increased in recent years, as has the incidence of injuries in female sports activities. These injuries are conditioned by... (Review)
Review
The presence of female athletes has only increased in recent years, as has the incidence of injuries in female sports activities. These injuries are conditioned by multiple factors, including hormonal agents. It is estimated that the menstrual cycle may be related to the predisposition to suffer an injury. However, a causal relationship has not yet been established. The aim of this study was to analyse the relationship between the menstrual cycle and injuries in female sports practice. A systematic search of the scientific literature available in PubMed, Medline, Scopus, Web of Science, and Sport Discus was carried out in January 2022. With 138 articles, only eight studies were found that met the selection criteria for this study. Peak estradiol is associated with increased laxity, strength, and poor use of neuromuscular control. Thus, the ovulatory phase is associated with an increased risk of injury. In conclusion, it seems that hormonal fluctuations throughout the menstrual cycle alter values such as laxity, strength, body temperature, and neuromuscular control, among others. This fact causes women to constantly adapt to hormonal variations, which exposes them to a higher risk of injury.
Topics: Female; Humans; Sports; Menstrual Cycle; Athletes; Estradiol; Adaptation, Physiological; Athletic Injuries
PubMed: 36833966
DOI: 10.3390/ijerph20043264 -
Journal of Applied Physiology... Dec 2023Hormonal changes around ovulation divide the menstrual cycle (MC) into the follicular and luteal phases. In addition, oral contraceptives (OCs) have active (higher... (Meta-Analysis)
Meta-Analysis Review
Hormonal changes around ovulation divide the menstrual cycle (MC) into the follicular and luteal phases. In addition, oral contraceptives (OCs) have active (higher hormone) and placebo phases. Although there are some MC-based effects on various physiological outcomes, we found these differences relatively subtle and difficult to attribute to specific hormones, as estrogen and progesterone fluctuate rather than operating in a complete on/off pattern as observed in cellular or preclinical models often used to substantiate human data. A broad review reveals that the differences between the follicular and luteal phases and between OC active and placebo phases are not associated with marked differences in exercise performance and appear unlikely to influence muscular hypertrophy in response to resistance exercise training. A systematic review and meta-analysis of substrate oxidation between MC phases revealed no difference between phases in the relative carbohydrate and fat oxidation at rest and during acute aerobic exercise. Vascular differences between MC phases are also relatively small or nonexistent. Although OCs can vary in composition and androgenicity, we acknowledge that much more work remains to be done in this area; however, based on what little evidence is currently available, we do not find compelling support for the notion that OC use significantly influences exercise performance, substrate oxidation, or hypertrophy. It is important to note that the study of females requires better methodological control in many areas. Previous studies lacking such rigor have contributed to premature or incorrect conclusions regarding the effects of the MC and systemic hormones on outcomes. While we acknowledge that the evidence in certain research areas is limited, the consensus view is that the impact of the MC and OC use on various aspects of physiology is small or nonexistent.
Topics: Female; Humans; Contraceptives, Oral; Menstrual Cycle; Hormones; Progesterone; Hypertrophy
PubMed: 37823207
DOI: 10.1152/japplphysiol.00346.2023 -
International Journal of Environmental... Dec 2022This study aimed to identify factors associated with the prevalence and severity of menstrual-related symptoms. The protocol was registered in PROSPERO (CRD42021208432).... (Meta-Analysis)
Meta-Analysis Review
This study aimed to identify factors associated with the prevalence and severity of menstrual-related symptoms. The protocol was registered in PROSPERO (CRD42021208432). We conducted literature searches of PubMed and Ichushi-Web and used the Jonna Briggs Institute critical appraisal checklist to assess the quality. Of the 77 studies included in the meta-analysis, significant odds ratios (ORs) were obtained for eight factors associated with primary dysmenorrhea (PD): age ≥ 20 years (OR: 1.18; 95% confidence interval [CI]: 1.04−1.34), body mass index (BMI) < 18.5 kg/m2 (OR: 1.51; 95% CI: 1.01−2.26), longer menstrual periods (OR: 0.16; 95% CI: 0.04−0.28), irregular menstrual cycle (OR: 1.28; 95% CI: 1.13−1.45), family history of PD (OR: 3.80; 95% CI: 2.18−6.61), stress (OR: 1.88; 95% CI: 1.30−2.72), sleeping hours < 7 h (OR: 1.19; 95% CI: 1.04−1.35), and bedtime after 23:01 (OR: 1.30; 95% CI: 1.16−1.45). Two factors were associated with severity of PD (moderate vs. severe): BMI < 18.5 kg/m2 (OR: 1.89; 95% CI: 1.01−3.54) and smoking (OR: 1.94; 95% CI: 1.08−3.47). PD severity (mild vs. severe) and prevalence of premenstrual syndrome were associated with BMI < 18.5 kg/m2 (OR: 1.91; 95% CI: 1.04−3.50) and smoking (OR: 1.86; 95% CI: 1.31−2.66), respectively. The identified risk factors could be utilized to construct an appropriate strategy to improve menstrual symptoms and support women’s health.
Topics: Female; Humans; Young Adult; Adult; Dysmenorrhea; Prevalence; Menstruation Disturbances; Premenstrual Syndrome; Menstruation
PubMed: 36612891
DOI: 10.3390/ijerph20010569 -
Fertility and Sterility Oct 2022To synthesize the published literature to better understand the association between cesarean scar defects (CSDs) and abnormal uterine bleeding (AUB). In particular, we... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To synthesize the published literature to better understand the association between cesarean scar defects (CSDs) and abnormal uterine bleeding (AUB). In particular, we aimed to evaluate the risk and pattern(s) of CSD-associated AUB in addition to exploring the relationship between defect morphology with bleeding symptoms.
DESIGN
Systematic review and meta-analysis.
SETTING
Not applicable.
PATIENTS
Patients with CSD and reports of uterine bleeding as an outcome were identified in 60 studies from database searches.
INTERVENTIONS
Studies that investigated CSD (as defined by investigators) and reported uterine bleeding, menstrual bleeding, or AUB as an outcome were included.
MAIN OUTCOME MEASURES
The prevalence and risk of AUB (intermenstrual, postmenstrual, and unscheduled bleeding) in patients with confirmed CSD.
RESULTS
Nine studies reported on the prevalence of AUB in patients with a confirmed CSD. Patients with CSD were more likely to experience AUB, compared with those without CSD (relative risk, 3.47; 95% confidence interval [CI], 2.02-5.97; 6 studies, 1,385 patients; I = 67%). In a population of patients with at least 1 cesarean delivery, the prevalence of AUB in those with CSD was 25.5% (95% CI, 14.7-40.5; 6 studies, 667 patients, I = 93%). However, symptom prevalence was much higher in patients presenting for imaging for a gynecologic indication where the prevalence of AUB in the presence of a CSD was 76.4% (95% CI, 67.8-83.3; 5 studies, 505 patients; I = 71%). The mean menstrual duration in symptomatic patients with CSD was 13.4 days (95% CI, 12.6-14.2; 19 studies, 2,095 patients; I = 96%), and the mean duration of early-cycle intermenstrual bleeding was 6.8 days (95% CI, 5.7-7.8 days; 9 studies, 759 patients; I = 93%). The most common descriptor of CSD-associated AUB was "brown discharge". Patients with larger CSD experienced more bleeding symptoms.
CONCLUSION
There is a strong and consistent association between patients with CSD and AUB. These patients experience a unique bleeding pattern, namely prolonged menstruation and early-cycle intermenstrual bleeding. These data should provide impetus for including CSD as a distinct entity in AUB classification systems. High heterogeneity in our results calls for standardization of nomenclature and outcome reporting for this condition.
Topics: Cesarean Section; Cicatrix; Female; Humans; Metrorrhagia; Pregnancy; Uterine Diseases; Uterine Hemorrhage
PubMed: 35985862
DOI: 10.1016/j.fertnstert.2022.06.031 -
PloS One 2020The 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... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The 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.
PURPOSE
To systematically review and analyze existing research to determine the effect of menstrual cycle on RMR.
METHODS
We 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.
RESULTS
Thirty 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).
DISCUSSION
Limitations 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.
Topics: Basal Metabolism; Female; Humans; Menstrual Cycle; Rest
PubMed: 32658929
DOI: 10.1371/journal.pone.0236025 -
The Cochrane Database of Systematic... Sep 2019Exercise has a number of health benefits and has been recommended as a treatment for primary dysmenorrhoea (period pain), but the evidence for its effectiveness on...
BACKGROUND
Exercise has a number of health benefits and has been recommended as a treatment for primary dysmenorrhoea (period pain), but the evidence for its effectiveness on primary dysmenorrhoea is unclear. This review examined the available evidence supporting the use of exercise to treat primary dysmenorrhoea.
OBJECTIVES
To evaluate the effectiveness and safety of exercise for women with primary dysmenorrhoea.
SEARCH METHODS
We searched the Cochrane Gynaecology and Fertility specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, AMED and CINAHL (from inception to July 2019). We searched two clinical trial databases (inception to March 2019) and handsearched reference lists and previous systematic reviews.
SELECTION CRITERIA
We included studies if they randomised women with moderate-to-severe primary dysmenorrhoea to receive exercise versus no treatment, attention control, non-steroidal anti-inflammatory drugs (NSAIDs) or the oral contraceptive pill. Cross-over studies and cluster-randomised trials were not eligible for inclusion.
DATA COLLECTION AND ANALYSIS
Two review authors independently selected the studies, assessed eligible studies for risk of bias, and extracted data from each study. We contacted study authors for missing information. We assessed the quality of the evidence using GRADE. Our primary outcomes were menstrual pain intensity and adverse events. Secondary outcomes included overall menstrual symptoms, usage of rescue analgesic medication, restriction of daily life activities, absence from work or school and quality of life.
MAIN RESULTS
We included a total of 12 trials with 854 women in the review, with 10 trials and 754 women in the meta-analysis. Nine of the 10 studies compared exercise with no treatment, and one study compared exercise with NSAIDs. No studies compared exercise with attention control or with the oral contraceptive pill. Studies used low-intensity exercise (stretching, core strengthening or yoga) or high-intensity exercise (Zumba or aerobic training); none of the included studies used resistance training.Exercise versus no treatmentExercise may have a large effect on reducing menstrual pain intensity compared to no exercise (standard mean difference (SMD) -1.86, 95% confidence interval (CI) -2.06 to -1.66; 9 randomised controlled trials (RCTs), n = 632; I= 91%; low-quality evidence). This SMD corresponds to a 25 mm reduction on a 100 mm visual analogue scale (VAS) and is likely to be clinically significant. We are uncertain if there is any difference in adverse event rates between exercise and no treatment.We are uncertain if exercise reduces overall menstrual symptoms (as measured by the Moos Menstrual Distress Questionnaire (MMDQ)), such as back pain or fatigue compared to no treatment (mean difference (MD) -33.16, 95% CI -40.45 to -25.87; 1 RCT, n = 120; very low-quality evidence), or improves mental quality of life (MD 4.40, 95% CI 1.59 to 7.21; 1 RCT, n = 55; very low-quality evidence) or physical quality of life (as measured by the 12-Item Short Form Health Survey (SF-12)) compared to no exercise (MD 3.40, 95% CI -1.68 to 8.48; 1 RCT, n = 55; very low-quality evidence) when compared to no treatment. No studies reported on any changes in restriction of daily life activities or on absence from work or school.Exercise versus NSAIDsWe are uncertain if exercise, when compared with mefenamic acid, reduced menstrual pain intensity (MD -7.40, 95% CI -8.36 to -6.44; 1 RCT, n = 122; very low-quality evidence), use of rescue analgesic medication (risk ratio (RR) 1.77, 95% CI 1.21 to 2.60; 1 RCT, n = 122; very low-quality evidence) or absence from work or school (RR 1.00, 95% CI 0.49 to 2.03; 1 RCT, n = 122; very low-quality evidence). None of the included studies reported on adverse events, overall menstrual symptoms, restriction of daily life activities or quality of life.
AUTHORS' CONCLUSIONS
The current low-quality evidence suggests that exercise, performed for about 45 to 60 minutes each time, three times per week or more, regardless of intensity, may provide a clinically significant reduction in menstrual pain intensity of around 25 mm on a 100 mm VAS. All studies used exercise regularly throughout the month, with some studies asking women not to exercise during menstruation. Given the overall health benefits of exercise, and the relatively low risk of side effects reported in the general population, women may consider using exercise, either alone or in conjunction with other modalities, such as NSAIDs, to manage menstrual pain. It is unclear if the benefits of exercise persist after regular exercise has stopped or if they are similar in women over the age of 25. Further research is required, using validated outcome measures, adequate blinding and suitable comparator groups reflecting current best practice or accounting for the extra attention given during exercise.
Topics: Dysmenorrhea; Exercise; Fatigue; Female; Humans; Menstruation; Quality of Life; Randomized Controlled Trials as Topic
PubMed: 31538328
DOI: 10.1002/14651858.CD004142.pub4 -
Revista Colombiana de Obstetricia Y... Jun 2020To conduct a systematic review of the literature and assess the acceptability and safety of the menstrual cup as a feminine hygiene product.
OBJECTIVES
To conduct a systematic review of the literature and assess the acceptability and safety of the menstrual cup as a feminine hygiene product.
MATERIALS AND METHODS
A search was conducted in the PubMed, Cochrane Library, Scopus, PopLine and Google Scholar databases for publications be- tween 1966 and July 2019. The terms ("Menstrual" AND "Cup") OR ("Copa" AND "Menstrual") were used. Quantitative, qualitative and mixed studies were included, as well as case series and case reports published in English and Spanish assessing the menstrual cup in women in childbearing age. The studies were selected and the data extracted by two reviewers working independently. Acceptability and safety were assessed as the primary result. The summary of the information is presented in narrative form.
RESULTS
Overall, 737 titles were found for initial review and, in the end, 38 studies were included in this work. The acceptability of the menstrual cup ranges between 35 % and 90 %. Between 10 to 45 % of women found it difficult to use. It was described as more comfortable when compared to tampons and pads. Continued use of the cup ranges between 48 and 94 %. In terms of safety, there was one case of toxic shock syndrome, one case of mechanical entrapment, and another case of allergy; and a higher risk of expulsion was found among intrauterine device users.
CONCLUSION
The menstrual cup appears to be a comfortable, safe and efficient option for menstrual hygiene. Further randomized controlled studies and long-term prospective cohort studies are needed in order to determine the risk of complications due to excess bacterial colonization or retrograde menstruation.
Topics: Adolescent; Adult; Cross-Sectional Studies; Equipment Contamination; Equipment Design; Female; Humans; Menstrual Hygiene Products; Middle Aged; Patient Acceptance of Health Care; Prospective Studies; Randomized Controlled Trials as Topic; Shock, Septic; Young Adult
PubMed: 32770872
DOI: 10.18597/rcog.3425