A case-control study of thallium exposure with the risk of premature ovarian insufficiency in women

Mechanism Exploration of Environmental Pollutants on Premature Ovarian Insufficiency: a Systematic Review and Meta-analysis

As a public health problem, premature ovarian insufficiency leads to infertility or sub-fertility. In addition to premature ovarian insufficiency (POI) increases the lifetime risk of bone fragility, cardiovascular disease, and cognitive impairment. To investigate the effects of environmental pollutants on the occurrence of POI and explore its mechanism, we conducted a computer search for articles published in electronic databases by December 13, 2022. Three reviewers independently examined all included studies and scored the qualities of included studies using the Newcastle-Ottawa Scale criteria. In this meta-analysis, eight clinical studies as well as ten preclinical findings showed a pooled OR of 2.331 and 95% CI of 1.968-2.760. This confirms that environmental pollutants, including POPs, heavy metals, PAEs, PAHs, cosmetic and pharmaceutical products, and cigarette smoke, are indeed significant risk factors for POI. In addition, it is demonstrated from the results of this study that signaling pathway of calcium and PI3K Akt and Xpnpep2, Col1, Col3, Col4, Cx43, Egr3, Tff1, and Ptgs2 genes may all be involved in the process. Environmental pollutants, including POPs, heavy metals, PAEs, PAHs, cosmetic and pharmaceutical products, and cigarette smoke, are indeed significant risk factors for POI.

Heavy Metals and Essential Elements in Association with Oxidative Stress in Women with Polycystic Ovary Syndrome-A Systematic Review

Altered levels of heavy metals and essential elements have been associated with oxidative stress (OS) and metabolic and hormonal changes in women with polycystic ovary syndrome (PCOS). We aimed to summarize the knowledge on the association of heavy metals and essential elements with OS in PCOS. An electronic literature search using PubMed for studies published between January 2008 and April 2023 was conducted. We evaluated heavy metals and essential elements in relation to OS in PCOS in 15 articles. PCOS women had increased antimonium (Sb), cadmium (Cd), lead (Pb), mercury (Hg), arsenic (As), tellurium (Te), thallium (Tl) and osmium (Os) blood levels and decreased zinc (Zn) blood levels; the results of copper (Cu) blood levels were conflicting. Some studies showed a significant correlation between heavy metals (Sb, Cd, Pb, Hg, As, Te and Tl) and essential elements (Se, Zn, Cr, Ca, Mg and Cu) and markers of OS and chronic inflammation. Heavy metals (Sb, Cd, Pb and Hg) and essential elements (Zn, Cr, Se, Ca, Mg and Cu) were associated with metabolic and hormonal characteristics in PCOS. There might be a possible benefit from supplementation therapy in reducing OS and endocrinological problems related to PCOS. Our review confirmed an association between heavy metals and essential elements with OS in PCOS women. This systematic review is registered in PROSPERO under number CRD42023418453.

Anti-Müllerian hormone for the diagnosis and prediction of menopause: a systematic review

BACKGROUND

The early onset of menopause is associated with increased risks of cardiovascular disease and osteoporosis. As a woman's circulating anti-Müllerian hormone (AMH) concentration reflects the number of follicles remaining in the ovary and declines towards the menopause, serum AMH may be of value in the early diagnosis and prediction of age at menopause.

OBJECTIVE AND RATIONALE

This systematic review was undertaken to determine whether there is evidence to support the use of AMH alone, or in conjunction with other markers, to diagnose menopause, to predict menopause, or to predict and/or diagnose premature ovarian insufficiency (POI).

SEARCH METHODS

A systematic literature search for publications reporting on AMH in relation to menopause or POI was conducted in PubMed®, Embase®, and the Cochrane Central Register of Controlled Trials up to 31 May 2022. Data were extracted and synthesized using the Synthesis Without Meta-analysis for diagnosis of menopause, prediction of menopause, prediction of menopause with a single/repeat measurement of AMH, validation of prediction models, short-term prediction in perimenopausal women, and diagnosis and prediction of POI. Risk-of-bias was evaluated using the Tool to Assess Risk of Bias in Cohort Studies protocol and studies at high risk of bias were excluded.

OUTCOMES

A total of 3207 studies were identified, and 41, including 28 858 women, were deemed relevant and included. Of the three studies that assessed AMH for the diagnosis of menopause, one showed that undetectable AMH had equivalent diagnostic accuracy to elevated FSH (>22.3 mIU/ml). No study assessed whether AMH could be used to shorten the 12 months of amenorrhoea required for a formal diagnosis of menopause. Studies assessing AMH with the onset of menopause (27 publications [n = 23 835 women]) generally indicated that lower age-specific AMH concentrations are associated with an earlier age at menopause. However, AMH alone could not be used to predict age at menopause with precision (with estimates and CIs ranging from 2 to 12 years for women aged <40 years). The predictive value of AMH increased with age, as the interval of prediction (time to menopause) shortened. There was evidence that undetectable, or extremely low AMH, may aid early diagnosis of POI in young women with a family history of POI, and women presenting with primary or secondary amenorrhoea (11 studies [n = 4537]).

WIDER IMPLICATIONS

The findings of this systematic review support the use of serum AMH to study the age of menopause in population studies. The increased sensitivity of current AMH assays provides improved accuracy for the prediction of imminent menopause, but diagnostic use for individual patients has not been rigorously examined. Prediction of age at menopause remains imprecise when it is not imminent, although the finding of very low AMH values in young women is both of clinical value in indicating an increased risk of developing POI and may facilitate timely diagnosis.