Urinary 6-sulfatoxymelatonin excretion in hyperandrogenic women with polycystic ovary syndrome: the effect of ethinyl estradiol-cyproterone acetate treatment

Circadian rhythm disruption and polycystic ovary syndrome: a systematic review and meta-analysis

Objective

The aim of our systematic review and meta-analysis was to determine if circadian rhythm disruption (CRD) is associated with polycystic ovary syndrome (PCOS). Our objective was to pool the overall mean differences in biomarkers of CRD (including melatonin levels, morning and evening cortisol levels, and sleep efficiency) between PCOS patients and controls. We hypothesized that CRD will be more prominent in patients with PCOS.

Data sources

A systematic search of PubMed, Scopus, Embase, ClinicalTrials.Gov, and the Cochrane Database of Systematic Reviews was conducted from inception until 2024 using the following MeSH terms "circadian rhythm" OR "sleep disturbance" OR "melatonin" AND "polycystic ovary syndrome." Citation search supplemented the systematic database search.

Study eligibility criteria

Inclusion criteria were women with PCOS, original case-control, cross-sectional, and cohort studies that identify parameters of CRD (melatonin, cortisol, and sleep disturbance). Exclusion criteria were women with endocrine and metabolic co-morbidities, menopausal women, case reports, review studies, animal studies, abstracts, and conference presentations. There was no time restriction for year of publication.

Study appraisal and synthesis methods

Two investigators (T.H. and P.R.) assessed the quality of the studies included using the Newcastle-Ottawa Scale. Forest plots were created using the Open Meta Analyst software. Publication bias was assessed in Egger's and Begg's tests.

Results

A total of 16 studies were included in the systematic review and 12 studies were included in the meta-analysis (N=1,100 women [531 PCOS patients and 569 controls]). Pooled analysis showed that the mean difference in melatonin levels between PCOS patients and controls was 14.294 pg/mL, 95% CI [6.895, 21.693]. The overall mean difference in morning and evening cortisol between PCOS patients and controls was 1.103 pg/mL, 95% CI [-1.058, 3.265], and 3.574 pg/mL, 95% CI [1.741, 5.407], respectively. Pooled difference in mean sleep efficiency scores between PCOS patients and controls was -4.059, 95% CI [-6.752, -1.366]. Risk of bias assessment showed that NOS scores ranged from 7 to 9.

Conclusions

Our meta-analysis provides evidence that circadian rhythm disruption is positively associated with polycystic ovary syndrome. This is substantiated by differences in parameters indicative of circadian rhythm disruption, including melatonin levels, evening cortisol, and sleep efficiency.

Women with polycystic ovary syndrome (PCOS) have reduced melatonin concentrations in their follicles and have mild sleep disturbances

Background

Polycystic ovary syndrome (PCOS) is a common gynecologic disorder related to abnormal circadian rhythm. Therefore, we aimed to find whether the level of melatonin, a rhythm regulating hormone changed in the ovarian microenvironment in this disease.

Methods

The melatonin concentrations in follicular fluid (FF) were measured in 35 PCOS and 36 non-PCOS women undergoing in vitro fertilization (IVF) treatment.

Results

The FF melatonin concentration was significantly lower in PCOS women than non-PCOS women (p = 0.045) and it was found positively correlated with serum basal FSH level (r = 0.308, p = 0.013). In IVF procedures, there was no significant difference in the fertilization rate of oocytes between the two groups, but the high-quality embryogenesis rate on the third day of the PCOS group was significantly lower than that of the control group (p = 0.042), which showed a weak positive correlation with the FF melatonin concentration (r_s = 0.240, p = 0.044). Furthermore, there was no significant difference in overall pregnancy outcome. The PSQI questionnaire showed that sleep disorders were more likely to exist in the PCOS group, though there was no significant difference.

Conclusion

The obtained results suggested PCOS women had lower melatonin concentrations in the ovarian microenvironment.

[Analysis of melatonin concentration and its correlation with ovarian disfunction among obese women of reproductive age]

Одним из новых направлений в изучении нарушений репродуктивной функции у женщин с ожирением являются влияние и рецепторная чувствительность мелатонина на гонадотропную функцию гипофиза и овариогенез с учетом хронологии «светового загрязнения». На современном этапе литературы по влиянию аспектов «светового загрязнения» на проблему ожирения и нарушений репродуктивной функции в отечественной и зарубежной литературе крайне мало. Данный обзор является попыткой объединить вышеуказанную проблему в рамках аспектов влияния «светового загрязнения» и уровня рецепторной чувствительности мелатонина у женщин репродуктивного возраста с ожирением. Поиск литературы проводили в отечественных (eLibrary, CyberLeninka.ru) и международных (PubMed, Cochrane Library) базах данных на русском и английском языках. Приоритетным являлся свободный доступ к полному тексту статей. Выбор источников был приоритетен периодом с 2015 по 2019 гг. Однако с учетом недостаточной изученности выбранной темы выбор источников датировался с 1992 г. Работа выполнена в рамках Государственного задания «Центральные и периферические патофизиологические механизмы развития болезней жировой ткани с учетом клинических и гормональных характеристик», 2020–2022 гг.

The role of melatonin in polycystic ovary syndrome: A review

Background

Polycystic ovary syndrome (PCOS) is a widespread endocrine disorder, affecting approximately 20% of women within reproductive age. It is associated with hyperandrogenism, obesity, menstrual irregularity, and anovulatory infertility. Melatonin is the main pineal gland hormone involved in the regulation of the circadian rhythm. In recent years, it has been observed that a reduction in melatonin levels of follicular fluid exists in PCOS patients. Melatonin receptors in the ovary and intra-follicular fluid adjust sex steroid secretion at different phases of ovarian follicular maturation. Moreover, melatonin is a strong antioxidant and an effective free radical scavenger, which protects ovarian follicles during follicular maturation.

Objective

In this paper, we conducted a literature review and the summary of the current research on the role of melatonin in PCOS.

Materials and Methods

Electronic databases including PubMed/MEDLINE, Web of Science, Scopus, and Reaxys were searched from their inception to October 2018 using the keywords “Melatonin” AND “Polycystic ovary syndrome” OR “PCOS.”

Results

Based on the data included in our review, it was found that the administration of melatonin can improve the oocyte and embryo quality in PCOS patients. It may also have beneficial effects in correcting the hormonal alterations in PCOS patients.

Conclusion

Since metabolic dysfunction is the major finding contributing to the initiation of PCOS, melatonin can hinder this process via its improving effects on metabolic functions.

Pathogenesis and Consequences of Disordered Sleep in PCOS

Polycystic ovary syndrome (PCOS) is a common hormonal disorder that is characterized by hyperandrogenism and menstrual irregularity. Affected women have a high prevalence of insulin resistance and related metabolic complications. The frequency of sleep disturbances appears to be increased in women with PCOS, although most studies so far have included more severely affected obese women with PCOS who are referred to tertiary care clinics and may not represent the general population of women with PCOS. This article provides an overview of sleep disturbances in PCOS with the focus on obstructive sleep apnea (OSA), the most commonly reported sleep disturbance among these women. The pathogenesis and risk factors for OSA in PCOS and its association with metabolic disorders is discussed in detail.

Steroidogenesis-related gene expression in the rat ovary exposed to melatonin supplementation

OBJECTIVE

To analyze steroidogenesis-related gene expression in the rat ovary exposed to melatonin supplementation.

METHODS

Thirty-two virgin adult female rats were randomized to two groups as follows: the control group GI received vehicle and the experimental group GII received melatonin supplementation (10 µg/night per animal) for 60 consecutive days. After the treatment, animals were anesthetized and the collected ovaries were immediately placed in liquid nitrogen for complementary deoxyribonucleic acid microarray analyses. A GeneChip(®) Kit Rat Genome 230 2.0 Affymetrix Array was used for gene analysis and the experiment was repeated three times for each group. The results were normalized with the GeneChip(®) Operating Software program and confirmed through analysis with the secondary deoxyribonucleic acid-Chip Analyzer (dChip) software. The data were confirmed by real-time reverse transcription polymerase chain reaction analysis. Genes related to ovarian function were further confirmed by immunohistochemistry.

RESULTS

We found the upregulation of the type 9 adenylate cyclase and inhibin beta B genes and the downregulation of the cyclic adenosine monophosphate response element modulator and cytochrome P450 family 17a1 genes in the ovarian tissue of GII compared to those of the control group.

CONCLUSION

Our data suggest that melatonin supplementation decreases gene expression of cyclic adenosine monophosphate, which changes ovarian steroidogenesis.

Melatonin and its correlation with testosterone in polycystic ovarian syndrome

CONTEXT

Polycystic ovarian syndrome (PCOS) is considered to be the most common endocrine disorder affecting women. Melatonin, a small lipophilic indoleamine, and reproductive hormones may be interrelated. Melatonin influences sex steroid production at different stages of ovarian follicular maturation as melatonin receptors have been demonstrated at multiple sites in ovary and in intrafollicular fluid. It plays role as an antioxidant and free radical scavanger which protects follicles from oxidative stress, rescuing them from atresia, leading to complete follicular maturation and ovulation.

AIMS

To study the role of melatonin in PCOS and to investigate its correlation with testosterone in patients suffering from PCOS.

SETTINGS AND DESIGN

A total of 50 women with PCOS (Rotterdam criteria, 2003) and 50 age and weight matched healthy controls were selected and serum melatonin estimation was done in both the groups and correlated with serum total testosterone levels.

MATERIALS AND METHODS

In a case-control study, detailed history, clinical examination and hormonal evaluation [basal levels of leutinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, prolactin, insulin, total testosterone, progesterone and melatonin] were carried out in all the participants including both cases and controls. For melatonin estimation, blood samples were collected between 12:00 am and 04:00 am on day 2(nd) of menstrual cycle and analyzed by using commercially available enzyme-linked immunosorbent assay kit.

STATISTICAL ANALYSIS

Student's t-test was used to compare the significant difference in mean values between cases and control groups. Chi-square test was used to test the significant association between the qualitative variables. Linear correlation coefficient and regression analysis were done to see the amount and direction of relationship between quantitative variables.

RESULTS

The mean melatonin level was observed to be significantly increased in patients (63.27 ± 10.97 pg/mL) than in controls (32.51 ± 7.55 pg/mL). Melatonin was found to be raised in all the cases of PCOS (above cut-off value of ≥45 pg/mL, P < 0.001). Total testosterone level was also raised in 72% of patients. Melatonin levels were found to be positively associated with increased testosterone (P < 0.001). In regression analysis using melatonin as dependent variable and testosterone as an independent variable, the value of R2 Χ 100 (percent variation) was found to be 72.1%.

CONCLUSIONS

Women with PCOS have significantly raised serum melatonin levels and hyperandrogenemia along with increased number of atretic follicles. Further studies are required to establish a definite role of melatonin in PCOS cases with disturbed hormonal milieu. This could open up the way for therapeutic role of melatonin in treatment of patients suffering from PCOS.

Poor sleep in PCOS; is melatonin the culprit?

STUDY QUESTION

Are daily cycles in urinary melatonin and oxidative stress marker levels (8-hydroxydeoxyguanosine) altered in PCOS, and is this associated with changes in sleep quality?

SUMMARY ANSWER

There is an association between elevated nighttime melatonin and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels, and poor sleep quality in our PCOS study group.

WHAT IS KNOWN ALREADY

Women with PCOS are known to have poorer sleep. However, there have been few studies examining the possible association between melatonin levels and sleep quality in women with polycystic ovarian syndrome (PCOS).

STUDY DESIGN, SIZE, DURATION

This is a case-control study of PCOS (n = 26) and non-PCOS control (n = 26) subjects recruited from a tertiary gynaecological centre.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The participants were requested to complete sleep questionnaires for a month. In a subgroup from these cohorts (PCOS, n = 15; controls, n = 18), urine samples were also collected at various time points over a 24-h period. In addition, their sleep patterns and lighting environment were monitored for 3 consecutive days and nights using a wrist-mounted Actiwatch device.

MAIN RESULTS AND THE ROLE OF CHANCE

PCOS women had significantly elevated night-time urinary levels of the melatonin metabolite 6-sulfatoxymelatonin (aMT6s) and of 8-OHdG (both at P < 0.05), as well as significantly reduced sleep quality (P < 0.05), compared with the controls.

LIMITATIONS, REASONS FOR CAUTION

Due to the small sample size of the study, further studies will be required to confirm our findings.

WIDER IMPLICATIONS OF THE FINDINGS

Our preliminary work provides a possible new insight into the interactions between melatonin, increased oxidative stress and sleep in women with PCOS.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Faculty of Medicine, University of Southampton.