Effect of cigarette smoking on serum anti-Mullerian hormone and antral follicle count in women seeking fertility treatment: a prospective cross-sectional study

The Concentration of Follistatin and Activin A in Serum and Selected Biochemical Parameters in Women with Polycystic Ovary Syndrome: Stratification by Tobacco Smoke Exposure, Insulin Resistance, and Overweight/Obesity

Background/Objectives: The aim of the study was to investigate the concentrations of follistatin and activin A in the serum of women with polycystic ovary syndrome (PCOS) and to assess their relationship with selected biochemical parameters, specifically stratifying the analysis based on tobacco smoke, insulin resistance, and abnormal weight. Methods: The research was carried out within a cohort of 88 women (60 women with and 28 without PCOS). Results: We observed significant differences (p < 0.05) in follistatin concentrations between women with PCOS stratified by homeostatic model assessment for insulin resistance (HOMA-IR) values. These differences were consistent across both smoking and non-smoking subgroups with PCOS. Similar results were observed when comparing normal-weight women with PCOS to those with overweight or obesity. Additionally, activin A concentrations were significantly increased by higher body mass index (BMI) and HOMA-IR values in non-smoking women with PCOS. Moreover, we identified a negative correlation (r = -0.30; p < 0.023) between cotinine levels and Anti-Müllerian hormone. Among smoking women with PCOS, we noted decreased concentrations of sex hormone-binding globulin and high-density lipoproteins, alongside increased fasting glucose, insulin, HOMA-IR, and free androgen index values. Conclusions: Our findings suggest that activin A and follistatin concentrations are more strongly influenced by disruptions in glucose metabolism and BMI than by tobacco smoke exposure. The observed changes were more pronounced in follistatin than in activin A level.

A systematic review of the association between modifiable lifestyle factors and circulating anti-Müllerian hormone

BACKGROUND

Levels of anti-Müllerian hormone (AMH) are known to be associated with lifestyle determinants such as smoking and oral contraception (OC) use. When measuring AMH in clinical practice, it is essential to know which factors may influence circulating levels or ovarian reserve in general.

OBJECTIVE AND RATIONALE

To date, there is no systematic review or summarizing consensus of the nature and magnitude of the relation between AMH and modifiable lifestyle factors. The purpose of this review was to systematically assess the evidence on association of lifestyle behaviors with circulating AMH levels.

SEARCH METHODS

We performed a pre-registered systematic review of publications in Embase and PubMed on the lifestyle factors BMI, smoking, OC use, alcohol consumption, caffeine consumption, physical activity, and waist-hip ratio (WHR) in relation to circulating AMH levels up to 1 November 2023. The search strategy included terms such as 'Anti-Mullerian hormone', 'lifestyle', and 'women'. Studies were considered eligible if the association between at least one of the lifestyle factors of interest and AMH was assessed in adult women. The quality of included studies was assessed using the Study Quality Assessment Tools of the National Heart, Lung, and Blood Institute. The results were presented as ranges of the most frequently used association measure for studies that found a significant association in the same direction.

OUTCOMES

A total of 15 072 records were identified, of which 65 studies were eligible for inclusion, and 66.2% of the studies used a cross-sectional design. The majority of studies investigating BMI, smoking, OC use, and physical activity reported significant inverse associations with AMH levels. For WHR, alcohol, and caffeine use, the majority of studies did not find an association with AMH. For all determinants, the effect measures of the reported associations were heterogeneous. The mean difference in AMH levels per unit increase in BMI ranged from -0.015 to -0.2 ng/ml in studies that found a significant inverse association. The mean difference in AMH levels for current smokers versus non-smokers ranged from -0.4 to -1.1 ng/ml, and -4% to -44%, respectively. For current OC use, results included a range in relative mean differences in AMH levels of -17% to -31.1%, in addition to a decrease of 11 age-standardized percentiles, and an average decrease of 1.97 ng/ml after 9 weeks of OC use. Exercise interventions led to a decrease in AMH levels of 2.8 pmol/l to 13.2 pmol/l after 12 weeks in women with polycystic ovary syndrome or a sedentary lifestyle.

WIDER IMPLICATIONS

Lifestyle factors are associated with differences in AMH levels and thus should be taken into account when interpreting individual AMH measurements. Furthermore, AMH levels can be influenced by the alteration of lifestyle behaviors. While this can be a helpful tool for clinical and lifestyle counseling, the nature of the relation between the observed differences in AMH and the true ovarian reserve remains to be assessed.

REGISTRATION NUMBER

PROSPERO registration ID: CRD42022322575.

Factors affecting the distribution of serum anti-müllerian hormone levels among infertile Asian women: a multi-nation, multi-centre, and multi-ethnicity prospective cohort study

STUDY QUESTION

How do age, ethnicity, and other characteristics affect serum anti-mullerian hormone (AMH) levels in Asian women undergoing fertility treatment?

SUMMARY ANSWER

Age, ethnicity, obesity (BMI ≥ 30 kg/m2), and polycystic ovarian syndrome (PCOS) significantly impacted serum AMH levels, with the rate of decrease accelerating as age increased; a concentration of 4.0 ng/ml was the optimal cut-off for diagnosis of PCOS.

WHAT IS KNOWN ALREADY

There are significant differences in ovarian reserve among women from different races and ethnicities, and Asian women often have poorer reproductive outcomes during assisted reproductive treatment cycles.

STUDY DESIGN, SIZE, DURATION

A population-based multi-nation, multi-centre, multi-ethnicity prospective cohort study of 4613 women was conducted from January 2020 to May 2021. Infertile women of 20-43 years of age were enrolled. The exclusion criteria included: age <20 or >43, non-Asian ethnicity, and missing critical data.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were Asian women of Chinese, Japanese, Korean, Thai, Vietnamese, Malay, Indian, and Indonesian ethnicities from 12 IVF centres across Asia. These women were all naïve to ovarian stimulation cycles and attended IVF centres for fertility assessment. The AMH measurement was performed using an AMH automated assay on a clinically validated platform.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 4556 infertile Asian women were included in the final analyses. The mean ± SD for serum AMH concentrations (ng/ml) across specific age groups were: overall, 3.44 ± 2.93; age <30, 4.58 ± 3.16; 30-31, 4.23 ± 3.23; 32-33, 3.90 ± 3.06; 34-35, 3.21 ± 2.65; 36-37, 2.74 ± 2.44; 38-39, 2.30 ± 1.91; 40 and above, 1.67 ± 2.00. The rate of AMH decrease was ∼0.13 ng/ml/year in patients aged 25-33 and 0.31 ng/ml/year in women aged 33-43. The highest rates of PCOS were found in Indians (18.6%), Malays (18.9%), and Vietnamese (17.7%). Age (P < 0.001), ethnicity (P < 0.001), obesity (P = 0.007), PCOS (P < 0.001), and a history of endometrioma cystectomy (P = 0.01) were significantly associated with serum AMH values. Smoking status, pretreatment with GnRH agonist (GnRHa) or the oral contraceptive pill (OCP), freezing-thawing of blood samples, and sampling on Day 2 to Day 5 of the menstrual cycle or randomly did not appear to affect serum AMH levels. An AMH concentration of 4.0 ng/ml was the optimal cut-off for PCOS diagnosis with a sensitivity of 71.7% and specificity of 75.8% (AUC = 0.81, CI 95%: 0.79-0.83; P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

The incidence of PCOS was supposedly high in this cohort as some IVF clinics were tertiary referral centres for managing specific fertility issues encountered by women with PCOS. Treatment with GnRHa or OCP before AMH testing was regionally and ethnically confined, mostly in Hong Kong SAR and Japan. Moreover, this reference for serum AMH value is limited to Asian women of the ethnicities examined and may not apply to other ethnicities not included in the study.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to collate and construct age-specific reference ranges for serum AMH levels using the same bioassay on Asian women of different ethnicities. The findings of this investigation can assist clinicians to counsel and prognosticate about Asian women's ovarian reserve and reproductive potential, thus providing better strategies for personalized fertility interventions.

STUDY FUNDING/COMPETING INTEREST(S)

This study was technically supported by Ferring Pharmaceuticals and received no specific grant from any funding agency. All authors have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

NCT04203355.

Systematic review of acupuncture to improve ovarian function in women with poor ovarian response

OBJECTIVE

To determine the effect of acupuncture in treating poor ovarian response (POR).

METHODS

We searched MEDLINE (via PubMed), EMBASE, Allied and Complementary Medicine Database, CNKI, CBM, VIP database, Wanfang Database, and relevant registration databases from inception to January 30, 2023. In this review, both Chinese and English peer-reviewed literature were included. Only randomized controlled trials (RCTs) using acupuncture as an intervention for POR patients undergoing in vitro fertilization were considered.

RESULTS

Seven clinical randomized controlled trials (RCTs) were eventually included for comparison (516 women). The quality of included studies was generally low or very low. For the meta-analysis, seven studies showed that compared with controlled ovarian hyperstimulation (COH) therapy, acupuncture combined with COH therapy could significantly increase the implantation rate (RR=2.13, 95%CI [1.08, 4.21], p=0.03), the number of oocytes retrieved (MD=1.02, 95%CI [0.72, 1.32], p<0.00001), the thickness of endometrium (MD=0.54, 95%CI [0.13, 0.96], p=0.01), and the antral follicle count (MD=1.52, 95%CI [1.08, 1.95], p<0.00001), reduce follicle-stimulating hormone (FSH) levels (MD=-1.52, 95%CI [-2.41, -0.62], p=0.0009) and improve estradiol (E₂) levels (MD=1667.80, 95%CI [1578.29, 1757.31], p<0.00001). Besides, there were significant differences in the duration of Gn (MD=0.47, 95%CI [-0.00, 0.94], p=0.05) between the two groups. However, no statistical variation was observed in improving clinical pregnancy rate (CPR), fertilization rate, high-quality embryo rate, luteinizing hormone (LH) value, anti-mullerian hormone (AMH) value, or reducing the dose of gonadotropin (Gn) values between the acupuncture plus COH therapy group and the COH therapy group.

CONCLUSION

Acupuncture combined with COH therapy is doubtful in improving the pregnancy outcome of POR patients. Secondly, acupuncture can also improve the sex hormone level of POR women, and improve ovarian function. Furthermore, more RCTs of acupuncture in POR are needed to be incorporated into future meta-analyses.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42020169560.

Association between cigarette smoking and ovarian reserve among women seeking fertility care

INTRODUCTION

This study examined the association of smoking with ovarian reserve in a cross-sectional study of 207 women enrolled in the Louisville Tobacco Smoke Exposure, Genetic Susceptibility, and Infertility (LOUSSI) Study and assessed effect modification by NAT2 acetylator phenotype.

METHODS

Information on current smoking status was collected using a structured questionnaire and confirmed by cotinine assay. Serum anti-Müllerian hormone (AMH) levels were used to assess ovarian reserve. Diminished ovarian reserve (DOR) was defined as AMH <1ng/mL. Single nucleotide polymorphisms in the NAT2 gene, which metabolizes toxins found in cigarette smoke, were analyzed to determine NAT2 acetylator status. Linear and logistic regression were used to determine the effects of smoking on ovarian reserve and evaluate effect modification by NAT2. Regression analyses were stratified by polycystic ovary syndrome (PCOS) status and adjusted for age.

RESULTS

Current smoking status, either passive or active as measured by urinary cotinine assay, was not significantly associated with DOR. For dose-response assessed using self-report, the odds of DOR increased significantly for every additional cigarette currently smoked (Odds ratio, OR:1.08; 95% confidence interval, 95%CI:1.01-1.15); additionally, every 1 pack-year increase in lifetime exposure was associated with an increased odds of DOR among women without PCOS (OR: 1.08 95%CI: 0.99-1.18). These trends appear to be driven by the heavy or long-term smokers. Effect modification by NAT2 genotype was not established.

CONCLUSION

A history of heavy smoking may indicate increased risk of diminished ovarian reserve.

Ovarian Reserve Disorders, Can We Prevent Them? A Review

The ovarian reserve is finite and begins declining from its peak at mid-gestation until only residual follicles remain as women approach menopause. Reduced ovarian reserve, or its extreme form, premature ovarian insufficiency, stems from multiple factors, including developmental, genetic, environmental exposures, autoimmune disease, or medical/surgical treatment. In many cases, the cause remains unknown and resulting infertility is not ultimately addressed by assisted reproductive technologies. Deciphering the mechanisms that underlie disorders of ovarian reserve could improve the outcomes for patients struggling with infertility, but these disorders are diverse and can be categorized in multiple ways. In this review, we will explore the topic from a perspective that emphasizes the prevention or mitigation of ovarian damage. The most desirable mode of fertoprotection is primary prevention (intervening before ablative influence occurs), as identifying toxic influences and deciphering the mechanisms by which they exert their effect can reduce or eliminate exposure and damage. Secondary prevention in the form of screening is not recommended broadly. Nevertheless, in some instances where a known genetic background exists in discrete families, screening is advised. As part of prenatal care, screening panels include some genetic diseases that can lead to infertility or subfertility. In these patients, early diagnosis could enable fertility preservation or changes in family-building plans. Finally, Tertiary Prevention (managing disease post-diagnosis) is critical. Reduced ovarian reserve has a major influence on physiology beyond fertility, including delayed/absent puberty or premature menopause. In these instances, proper diagnosis and medical therapy can reduce adverse effects. Here, we elaborate on these modes of prevention as well as proposed mechanisms that underlie ovarian reserve disorders.

The Aftermath of Long-Term Cigarette Smoking on Telomere Length and Mitochondrial DNA Copy Number in Human Cumulus Cells Prior to In Vitro Fertilization-A Pilot Study

Cigarette smoking among women of reproductive age is known to take a toll on systemic health and fertility potential by severely impacting ovarian tissues and cells, such as granulosa and cumulus cells (CCs). The purpose of this study was to determine the potential damage caused by tobacco smoke at a molecular level in the CCs of females who had undergone in vitro fertilization. The level of intracellular damage was determined by estimating the average telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN), as well as the expression profile of telomere maintenance genes TERF1, TERF2, POT1 and microRNAs miR-155, miR-23a and miR-185. Western blotting analysis was performed to detect consequent protein levels of TERF1, TERF2 and POT1. Our results evidenced significantly lower relative TL and mtDNA-CN and a down-regulation pattern for all three described genes and corresponding proteins in the CCs of smokers compared with controls (p < 0.05). No significant differences were found in the miRNAs’ modulation. Combined, our data add another piece to the puzzle of the complex regulatory molecular networks controlling the general effects of tobacco smoke in CCs. This pilot study extends the until now modest number of studies simultaneously investigating the mtDNA-CN and TL pathways in the human CCs of smoking women.