The effects of N-acetylcysteine supplement on metabolic parameters in women with polycystic ovary syndrome: a systematic review and meta-analysis

Objectives

Polycystic ovary syndrome (PCOS) is a common endocrine disease, often accompanied by metabolic disorders. Metformin, as an insulin sensitizer, is widely used to improve the metabolic function of PCOS, but may have gastrointestinal side effects. Emerging evidence suggests that N-acetylcysteine (NAC) improves metabolic parameters in PCOS and may be a potential alternative to metformin.

Methods

We searched four online databases, PubMed, Embase, Web of Science, and Cochrane Library, from inception to April 1, 2023. The I2 statistic and Cochrane's Q test were employed to determine heterogeneity between studies, with an I2 value >50% or p < 0.1 considered significant. The data were expressed as standardized mean differences and corresponding 95% confidence intervals.

Results

A total of 11 randomized controlled trials were included in the final analysis, including 869 women with PCOS. The results showed that NAC caused more changes in body mass index (SMD: -0.16, 95% CI: -0.40 to 0.08), body weight (SMD: -0.25, 95% CI: -0.50 to 0.00), fasting insulin (SMD: -0.24, 95% CI: -0.53 to 0.06), ratio of fasting blood glucose to fasting insulin (SMD: 0.38, 95% CI: -0.33 to 1.08), total cholesterol (SMD: -0.11, 95% CI: -0.39 to 0.17), triglycerides (SMD: -0.18, 95% CI: -0.63 to 0.28), and low-density lipoprotein (SMD: -0.09, 95% CI: -0.51 to 0.33) compared with metformin. Compared with metformin or placebo, NAC significantly reduced fasting blood-glucose levels (SMD: -0.23, 95% CI: -0.43 to -0.04; SMD: -0.54, 95% CI: -1.03 to -0.05, respectively). In addition, NAC significantly reduced total cholesterol (SMD: -0.74, 95% CI: -1.37 to -0.12), and this effect was observed when NAC was compared with placebo. However, NAC reduced HDL levels in women with PCOS compared with metformin (SMD: -0.14, 95% CI: -0.42 to 0.14).

Conclusion

This study suggests that NAC is effective in improving metabolic parameters in PCOS and may be a promising nutritional supplement for the treatment of PCOS.Systematic review registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=415172, identifier CRD42022339171.

Polycystic Ovary Syndrome and Oxidative Stress-From Bench to Bedside

Oxidative stress (OS) is a condition that occurs as a result of an imbalance between the production of reactive oxygen species (ROS) and the body's ability to detoxify and neutralize them. It can play a role in a variety of reproductive system conditions, including polycystic ovary syndrome (PCOS), endometriosis, preeclampsia, and infertility. In this review, we briefly discuss the links between oxidative stress and PCOS. Mitochondrial mutations may lead to impaired oxidative phosphorylation (OXPHOS), decreased adenosine triphosphate (ATP) production, and an increased production of ROS. These functional consequences may contribute to the metabolic and hormonal dysregulation observed in PCOS. Studies have shown that OS negatively affects ovarian follicles and disrupts normal follicular development and maturation. Excessive ROS may damage oocytes and granulosa cells within the follicles, impairing their quality and compromising fertility. Impaired OXPHOS and mitochondrial dysfunction may contribute to insulin resistance (IR) by disrupting insulin signaling pathways and impairing glucose metabolism. Due to dysfunctional OXPHOS, reduced ATP production, may hinder insulin-stimulated glucose uptake, leading to IR. Hyperandrogenism promotes inflammation and IR, both of which can increase the production of ROS and lead to OS. A detrimental feedback loop ensues as IR escalates, causing elevated insulin levels that exacerbate OS. Exploring the relations between OS and PCOS is crucial to fully understand the role of OS in the pathophysiology of PCOS and to develop effective treatment strategies to improve the quality of life of women affected by this condition. The role of antioxidants as potential therapies is also discussed.

The effects of N-acetylcysteine on ovulation and sex hormones profile in women with polycystic ovary syndrome: a systematic review and meta-analysis

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases characterised by unusual levels of sex hormones and dysfunction of the ovaries. The infertility rate is high among patients with PCOS. Unusual hormonal status can lead to the inability of ovaries to release functional and mature follicles. Clinical trials on the effects of N-acetylcysteine (NAC) supplementation on ovulation and sex hormones profile in women with PCOS have been controversial. We performed a systematic review and meta-analysis to evaluate the potential effects of NAC supplementation on ovulation and sex hormones profile. PubMed, Scopus, Embase, Web of Science and Cochrane Central library international databases were searched till September 2021. Meta-analysis was performed using a random-effects approach in case of significant between-study heterogeneity. Eighteen studies, including 2185 participants, were included in the present meta-analysis. NAC significantly reduced total testosterone (TT) levels (standardised mean difference (SMD): −0·25 ng/ml; 95 % CI (−0·39, −0·10); ‘P < 0·001’, I2 = 53·9 %, P = 0·034) and increased follicle-stimulating hormone (FSH) levels (SMD: 0·39 mg/ml; 95 % CI (0·07, 0·71); P = 0·01, I2 = 70·9 %, P = 0·002). Oestrogen levels also increased after correcting publication bias. However, no significant effect was observed on the number of follicles, endometrial thickness, progesterone, serum luteinising hormone levels and sex hormone-binding globulin. The results indicated that NAC supplementation decreased TT levels and increased FSH levels. Overall, NAC supplementation might be effective in the improvement of reproductive system function in patients with PCOS.

Comparison of melatonin, oxytetracycline, and N-acetylcysteine pre-treatments in autologous intraperitoneal ovarian transplantation in rats

This study was aimed at investigating the effects of melatonin, oxytetracycline and N-acetylcysteine on the ovarian follicle reserves and surface epithelium in autologous intraperitoneal ovarian transplantation in rats. Thirty adult female Wistar Albino were selected and randomly divided into six groups (n = 5). Group 1, which was the control group, only had their abdomens opened and closed while Group 2 underwent ovarian transplantation. Group 3, 4, 5 and 6 received 20 μg/kg/IM melatonin, 10 mg/kg/IM oxytetracycline, 150 mg/kg/IP N-Asetil sistein (NAC) and 1% ethanol respectively 15 min before the ovarian transplantation. Vaginal cytology was performed to monitor the estrus phase and the follicle reserve and changes in the surface epithelium were histopathologically evaluated during the preparations. Moreover, cellular apoptosis in tissues was evaluated with immunofluorescence staining of Bcl-2 and Bax. The Bax/Bcl-2 ratio was then calculated as the mean fluorescence intensity (MFI) of Bax and Bcl-2 MFI. Dysplastic change was found only significantly higher in the transplantation group (G2) (p < 0.01). Histopathologically, it was found that the follicle reserve was preserved significantly in the oxytetracycline and melatonin treated group (G3, G4) (p < 0.01). It was also observed that the oxytetracycline treated group (G4) were able to show better preventive effects against dysplastic changes of the surface epithelium. Moreover, the melatonin treated group depicted a low Bax/Bcl-2 ratio compared to the group that only underwent transplantation (G2) (p < 0.01). This study indicated that oxytetracycline and melatonin might be more effective than N-acetylcysteine in protecting against oxidative stress during ovarian transplantation.

Metformin Therapy for Acne in Patients with Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis

BACKGROUND

Acne is one of the cutaneous manifestations of polycystic ovary syndrome (PCOS). There is limited evidence on metformin use for treatment of acne in PCOS patients.

OBJECTIVE

Our aim was to conduct a systematic review and meta-analysis to evaluate the efficacy of metformin for treatment of PCOS-related acne.

METHODS

On November 23, 2019, we searched PubMed, the Cochrane Library, and Embase databases for human clinical studies in any language. The keywords included 'acne' and 'polycystic ovary syndrome' combined with 'metformin,' 'biguanide,' or 'glucophage.' We included randomized controlled trials (RCTs), non-randomized controlled trials (NRCTs), and open-label studies on patients with PCOS treated with metformin. We calculated standardized mean differences (SMDs) for acne scores and odds ratios (ORs) for presence of acne, with 95% confidence intervals (CIs). Quality assessment was performed using the Cochrane Collaboration risk of bias instrument for RCTs. NRCTs and open-label studies were assessed using the adapted methodological index for nonrandomized studies (MINORS).

RESULTS

We included 51 studies on 2405 PCOS patients. Metformin as adjuvant therapy led to greater improvement of acne scores than the same therapy without metformin (SMD - 0.256; 95% CI - 0.439 to - 0.074). Pooling pre- and post-metformin therapy data showed significant decrease of acne scores after metformin use (SMD - 0.712; 95% CI - 0.949 to - 0.476). Presence of acne decreased significantly after metformin treatment (OR 0.362; 95% CI 0.271 to 0.485).

LIMITATIONS

There was heterogeneity across some studies due to different acne assessment scales, metformin dosages, and treatment durations.

CONCLUSIONS

For PCOS patients, metformin as stand-alone or adjuvant therapy was associated with improvement of acne. More randomized controlled trials are needed to validate these results.

REGISTRATION

PROSPERO registration number CRD42020159656.

N-acetyl-cysteine as adjuvant therapy in female infertility: a systematic review and meta-analysis

OBJECTIVES

The objective of this study is to explore the efficacy and safety of N-acetyl-cysteine (NAC) as adjuvant therapy in female infertility.

CONTENT

We performed a systematic literature search of PubMed, Cochrane Library, Embase, and Ovid databases through April 2019 for Randomized Controlled Trials (RCTs) evaluating the effectiveness and safety of NAC as adjuvant therapy in female infertility. The outcomes assessed were rates of ovulation, pregnancy, miscarriage and multiple pregnancy, presented as pooled odds ratio with 95% confidence interval (CI) using the random-effects model. Heterogeneity and inconsistency of the measurements were identified through Cochrane's Q statistic and I2 statistic. We also performed a sensitivity analysis, publication bias (using funnel plot and Begg's test), and subgroup analysis.

SUMMARY

Fifteen RCTs recruiting 2330 female receiving NAC were included. The pooled estimate showed the statistically insignificant improvement in outcomes; clinical pregnancy rate 1.55 (95% CI 0.98-2.47; I2=68%; p<0.01), ovulation rate 1.77 (95% CI 0.76-4.14; I2=90%; p<0.01), multiple pregnancy rate 0.83 (95% CI 0.34-1.99; I2=10%; p=0.31) and miscarriage rate 0.76 (95% CI= 0.37, 1.53; I2=0%; p=0.69) . NAC was found less efficacious and safe than metformin in all outcomes. Overall, NAC showed statistically insignificant (OR=0.98-2.47).

OUTLOOK

NAC can be an effective adjuvant in PCOS related and unexplained female infertility. The effect could be more profound in women with high BMI, insulin resistance, and oxidative stress. However, the findings need further confirmation in well-designed randomized controlled trials to examine clinical outcomes such as live birth rate in more extended follow-up periods.

Pathophysiological roles of chronic low-grade inflammation mediators in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common hormonal imbalance disease in reproductive-aged women. Its basic characteristics are ovulatory dysfunction and ovarian overproduction of androgens that lead to severe symptoms such as insulin resistance, hirsutism, infertility, and acne. Notwithstanding the disease burden, its underlying mechanisms remain unknown, and no causal therapeutic exists. In recent years, further studies showed that inflammation processes are involved in ovulation and play a key role in ovarian follicular dynamics. Visceral adipose tissue can cause inflammatory response and maintenance of the inflammation state in adipocytes by augmented production of inflammatory cytokines, monocyte chemoattractant proteins, and recruitment of the immune cell. Therefore, the PCOS can be related to a low-grade inflammation state and inflammatory markers. Investigating the inflammatory processes and mediators that contribute to the commencement and development of PCOS can be a critical step for better understanding the pathophysiology of the disease and its treatment through inhibition or control of related pathways. In the present review, we discuss the pathophysiological roles of chronic low-grade inflammation mediators including inflammasome-related cytokines, interleukin-1β (IL-1β), and IL-18 in PCOS development.

Comparison of the efficacy between NAC and metformin in treating PCOS patients: a meta-analysis

Our aim is to evaluate the clinical effectiveness and safety by comparing N-acetyl-cysteine (NAC) with metformin administrated by polycystic ovary syndrome (PCOS) patients. Systematic review and meta-analysis of randomized clinical trials (RCTs). MEDLINE, EMBASE, Web of Science and China National Knowledge Infrastructure were searched for studies. 10 studies were considered eligible for inclusion. NAC significantly reduced BMI and total testosterone, there was no significant difference in pregnancy rate, serum LH level, fasting insulin, and LH/FSH ratio. In conclusions, NAC may be considered as an alternative supplement to metformin, but large-scale randomized controlled trials are needed to assess the efficacy and safety of NAC in PCOS patients.

Oxidative stress and cardiovascular complications in polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is a complex endocrine condition which is associated with metabolic and cardiovascular complications. It is elevated to a metabolic disorder with significant long term health ramification due to the high prevalence of insulin resistance (IR), impaired glucose tolerance, type 2 diabetes (T2D), dyslipidemia and numerous cardiovascular risk factors in PCOS women. This article concentrates on the recent developments in the regulation of oxidative stress (OS) in PCOS and on the association between PCOS and CVD outcomes. The prognostic events that define the severity of PCOS and involvement of cardiovascular risk in PCOS include endothelial dysfunction (ED) and impaired cardiac structure. Fact is that, in PCOS women, the circulating biomarkers of OS are in abnormal levels that are independent of overweight, which depicts the participation of OS in the pathophysiology of this common derangement. In addition, hyperglycemia (HG) per se, promotes reactive oxygen species (ROS) generation in PCOS. When the destructive ROS outbalances the concentration of physiological antioxidants, OS occurs. The resultant OS, directly stimulates hyperandrogenism and causes extensive cellular injury, DNA damage and/or cell apoptosis. To further the burden, the total serum antioxidant level in PCOS women is compromised, which diminishes the body's defense against an oxidative milieu. Thus, it is evident that OS regulates several cellular mechanisms in PCOS. Improving our understanding about the regulation of OS, critical role of ROS and protein biomarkers in PCOS should lead to novel therapeutic strategies in addressing PCOS-induced CVD. Besides, it is possible that the beneficial effects of dietary or therapeutic antioxidants have significant clinical relevance in PCOS.