Clinical, Hormonal, and Metabolic Parameters in Women with Subclinical Hypothyroidism and Polycystic Ovary Syndrome: A Cross-Sectional Study

Is thyroid function associated with polycystic ovary syndrome? A bidirectional Mendelian randomization study

OBJECTIVE

Some observational studies have suggested the association between thyroid function and polycystic ovary syndrome (PCOS). However, it remains to be determined whether these associations are causal or not. The aim of this study was to investigate the underlying causal association between different thyroid function status and PCOS.

METHODS

Bidirectional Mendelian randomization (MR) analysis was conducted to explore the impact of different thyroid function statuses on PCOS. The study included 10,074 individuals with PCOS and 103,164 controls for the primary analysis, with validation analysis repeated in the FinnGen R9 and EstBB PCOS cohorts. Female-specific thyroid function GWAS data were obtained from European population, including Hyperthyroidism (22,383 cases and 54,288 controls) and Hypothyroidism (27,383 cases and 54,288 controls) from the UK Biobank, and TSH (54,288 cases and 72,167 controls) and FT4 (49,269 cases and 72,167 controls) within the reference range from the ThyroidOmics Consortium. Inverse variance weighting (IVW) was chosen as the principal method, and sensitivity analysis was conducted to test for the presence of horizontal pleiotropy or heterogeneity.

RESULTS

The IVW analysis indicated nominal significance between normal TSH levels and PCOS after adjusted for age and BMI [OR (95% CI) = 0.78(0.62,0.97), P = 0.029], suggesting that maintaining normal TSH levels might act as a protective factor against the pathogenesis of PCOS. Besides, in order to increase the statistical power, we pooled PCOS GWAS above together by meta-analysis and found PCOS contributed to the occurrence of hyperthyroidism [OR(95%CI) = 1.37(0.73,2.57), P = 0.012]. However, no causal relationship was found after Bonferroni correction (P-value < 0.0031).

CONCLUSION

Although the MR analysis didn't indicate genetic causal association between thyroid function and PCOS after Bonferroni correction. Further efforts are needed to interpret the potential causal relationship between thyroid function and PCOS in different age and BMI subgroup.

The Associations Between Alanine Aminotransferase and Other Biochemical Parameters in Lean PCOS

To explore the associations of alanine aminotransferase in lean women of polycystic ovary syndrome (PCOS) with other biochemical parameters and the potential risk factors. This is a retrospective cohort study with lean PCOS (n = 91) and healthy controls (n = 45); we reviewed the electrical records and databases of the PCOS patients in our infertility clinic between January 2019 and September 2021; independent t-test, linear correlation analysis, and multiple linear regression were used to explore the associations. Higher levels of luteinizing hormone, total testosterone, thyroid stimulating hormone, platelet count, lymphocyte count, homocysteine, alanine aminotransferase (ALT), and uric acid were identified in lean PCOS patients, while follicle-stimulating hormone level was lower in in lean PCOS as expected (P < 0.05). Of note, the linear correlation showed that BMI, total testosterone, white blood cell count, lymphocyte count, aspartate aminotransferase, and uric acid were positively associated with alanine aminotransferase (r = 0.232, 0.318, 0.218, 0.388, 0.602, 0.353 respectively, P < 0.05). After multiple linear regression was performed, total testosterone and aspartate aminotransferase were independently and positively correlated with alanine aminotransferase in lean PCOS (B = 0.251, 0.605 respectively, P < 0.05). Higher level of ALT was identified in the lean PCOS. BMI, white blood cell count, lymphocyte count, aspartate aminotransferase, uric acid, and total testosterone were positively correlated with ALT in lean PCOS. Total testosterone and aspartate aminotransferase were independently and positively associated with ALT in lean PCOS after multiple linear regression. There might exist a potential risk of afflicting liver impairment for the lean PCOS women in the earlier period. Early examination and intervention might be necessary to prevent or delay the progression of the liver disease as soon as the diagnosis of PCOS.

Influence of Subclinical Hypothyroidism on Women With Polycystic Ovary Syndrome: A Literature Review

Subclinical hypothyroidism (SCH) is a commonly encountered condition in women with polycystic ovary syndrome (PCOS). Nevertheless, it is unclear whether SCH has any potential impact on the metabolic and reproductive profiles of women with PCOS. Hence, this literature review explores and establishes the link between these two conditions. In women with PCOS, SCH was found to aggravate insulin resistance and dyslipidemia. It was also linked to hormonal imbalances leading to higher infertility rates among the PCOS-SCH group. Therefore, women with PCOS must be screened for thyroid function frequently and managed accordingly.

Association of Subclinical Hypothyroidism with Present and Absent Anti-Thyroid Antibodies with PCOS Phenotypes and Metabolic Profile

BACKGROUND

Polycystic ovary syndrome (PCOS) and subclinical hypothyroidism (SCH) often coexist, but implications of the co-occurrence of two disorders have not yet been established. The objective is to conclude whether SCH with present or absent anti-thyroid antibodies (ATA) impacts on the PCOS phenotype and alters biochemical or clinical parameters.

METHODS

A retrospective cohort study was conducted in a tertiary reference center. Clinical and biochemical parameters of women with PCOS were analyzed.

RESULTS

A total of 367 women with PCOS were included in the study, 114 (31.1%) of whom were diagnosed with SCH and 16 (4.4%) with autoimmune thyroiditis (AIT). Among all parameters studied, the strongest relationship with SCH was confirmed for insulin resistance and dyslipidemia. SCH was an independent risk factor for insulin resistance. In SCH the additional presence of ATA did not exacerbate the metabolic disorders. There was no significant association of any PCOS phenotype with SCH, nor with the presence of circulating ATA. There was no significant difference in hormonal parameters and mFerriman-Gallwey scale score between women with PCOS with and without SCH.

CONCLUSIONS

SCH alters metabolic, but not hormonal, parameters in PCOS. The diagnosis of SCH does not exclude the diagnosis of PCOS. The potential effect of positive ATA was insignificant.

Frequency of Subclinical Hypothyroidism in Women With Polycystic Ovary Syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by hyperandrogenism and chronic anovulation. It may also influence thyroid hormones. Increasing evidence suggests that PCOS is linked with an increased prevalence of thyroid diseases such as nodular goiter, autoimmune thyroiditis, and subclinical hypothyroidism (SCH). Due to very limited global and regional data related to the prevalence of SCH in women with PCOS, we will determine the association between the two.

METHODS

This case-control study was conducted in the endocrinology ward of a tertiary care hospital in Pakistan from March 2020 to April 2021. We enrolled 200 females between the ages of 18 and 30 years, with documented evidence of PCOS in the study. Further 200 females without PCOS were enrolled as the case group. After demographics were noted, blood was drawn from their cubital vein via phlebotomy and sent to the laboratory to assess for thyroid-stimulating hormone, free thyroxine, and free triiodothyronine.

RESULTS

SCH was found to be more prevalent in participant with PCOS compared to participants without PCOS (43.5% vs. 20.5%; p-value: <0.00001). Increased weight (65.12 ± 5.62 kg vs. 60.02 ± 4.41 kg; p-value: <0.0001) and BMI (25.12 ± 2.51 kg/m² vs. 22.51 ± 2.01 kg/m²; p-value: <0.0001) was significantly more in participants with PCOS compared to participants without PCOS.

CONCLUSION

Based on our findings, this study demonstrated the strong association of SCH in women with PCOS as compared to their normal counterparts. Therefore, the clinical implication is to maintain a high index of suspicion for signs and symptoms of SCH, and awareness is needed for such women to enhance the reproductive and clinical pregnancy outcomes.

The Impact of Subclinical Hypothyroidism on Patients with Polycystic Ovary Syndrome: A Meta-Analysis

The association between subclinical hypothyroidism (SCH) and polycystic ovary syndrome (PCOS) has been shown in many studies. These findings are still controversial, however. It is unclear whether the co-incidence of subclinical hypothyroidism and polycystic ovary syndrome will affect the severity of metabolism. Therefore, we performed this meta-analysis to investigate the association. A comprehensive search strategy was developed to obtain all relevant studies published in PubMed, EMBASE, Cochrane Library, and Chinese Academic Journal Full-text Database (CNKI) up to 31 December 2020. We adopted the standardized mean difference (SMD) with 95% confidence intervals (CI) for evaluation, and sensitivity analysis was performed. Publication bias was analyzed and represented by a funnel plot, and funnel plot symmetry was assessed with Egger's test. Twenty-seven studies with 4821 participants (1300 PCOS patients with SCH, 3521 PCOS patients without SCH) were included in the present meta-analysis,among which 71.31% chinese patients out of the total. The results showed that PCOS patients with SCH had higher levels of HOMA-IR, TG, TC, LDL, FBG, FCP, PRL and lower levels of HDL, LH and T. It also recognized the limitation of the lack of a consistent definition of hypothyroidism in the 27 studies included. The results of this study indicated that SCH may aggravate lipid and glucose metabolism in patients with PCOS.

Genetic Susceptibility to Joint Occurrence of Polycystic Ovary Syndrome and Hashimoto's Thyroiditis: How Far Is Our Understanding?

Polycystic ovary syndrome (PCOS) and Hashimoto’s thyroiditis (HT) are endocrine disorders that commonly occur among young women. A higher prevalence of HT in women with PCOS, relative to healthy individuals, is observed consistently. Combined occurrence of both diseases is associated with a higher risk of severe metabolic and reproductive complications. Genetic factors strongly impact the pathogenesis of both PCOS and HT and several susceptibility loci associated with a higher risk of both disorders have been identified. Furthermore, some candidate gene polymorphisms are thought to be functionally relevant; however, few genetic variants are proposed to be causally associated with the incidence of both disorders together.

The Influence of Treated and Untreated Subclinical Hypothyroidism on Metabolic Profile in Women with Polycystic Ovary Syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) and hypothyroidism are the most common endocrinological disorders among women of reproductive age. Since hypothyroidism occurs more frequently in PCOS patients, it is vital to explain its clinical impact.

AIM

To evaluate the impact of subclinical hypothyroidism (SCH) and its treatment on the metabolic profile of patients with PCOS.

METHODS

190 women with PCOS phenotype A were enrolled in the case-control study. They were divided into three groups: 38 women with PCOS and subclinical hypothyroidism, 76 women with PCOS and SCH under thyroid replacement therapy, and 76 women with PCOS and normal thyroid function (control group). Serum lipids, fasting glucose, and insulin, as well as oral glucose tolerance tests were performed.

RESULTS

In the analyzed parameters, there were no statistic differences between the groups in relation to thyroid function. BMI turned out to be the main factor dividing the patients in terms of serum lipids, fasting glucose, fasting insulin, and oral glucose tolerance test. TSH was associated with total cholesterol and LDL cholesterol levels, whereas BMI has a dominant impact on HDL cholesterol, triglycerides, glucose, and insulin resistance.

CONCLUSIONS

SCH is associated with mild lipid serum alterations in women with PCOS, but it is BMI to have a dominant impact on glucose and insulin. It seems that treatment of SCH in PCOS does not significantly alter lipid and glucose metabolism.

Risk of Cardiovascular and Cerebrovascular Events in Polycystic Ovarian Syndrome Women: A Meta-Analysis of Cohort Studies

Aim: This systematic review and meta-analysis aimed to investigate the risk of cardiovascular disease (CVD) and cerebrovascular disease (CeVD) events in women with polycystic ovary syndrome (PCOS). Methods: We searched the literatures in Pubmed, Embase, and Web of Science to identify cohort studies reporting the association between PCOS and CVD/CeVD events from 1964 to June 1, 2020. Outcome variables, such as all-cause mortality, cardiovascular death, any cardiovascular diseases, myocardial infarction, ischemic heart disease, and stroke, were extracted from the identified literatures, and we reported the outcomes of the association in hazard ratios (HR) and odds ratios (OR). Results: Ten cohort studies comprising 166,682 samples are included in the review. Compared to non-PCOS women, the pooled risk of CVD events in PCOS women (OR: 1.66, 95% CI: 1.32-2.08). In addition, the risk of myocardial infarction (OR: 2.57, 95% CI: 1.37-4.82), ischemic heart disease (OR: 2.77, 95% CI: 2.12-3.61), and stroke (OR: 1.96, 95% CI: 1.56-2.47) are higher in the PCOS group. However, no significant difference in the overall mortality (HR: 1.04, 95% CI: 0.57-1.86) and CVD-related death (HR: 1.49, 95% CI: 0.99-2.23) was observed. Funnel plots of all outcomes are roughly symmetric, and no significant publication bias was found. Conclusion: Though this study identified an increased risk of CVD and CeVD among women with PCOS, including occurrence of myocardial infarction, ischemic heart disease, and stroke, there was no difference in the all-cause or CVD-related mortality observed. Further large-scale studies are warranted to strengthen the association between PCOS and CV events. Our study may require a larger sample size to further verify the conclusions.

Correlation of Subclinical Hypothyroidism With Polycystic Ovary Syndrome (PCOS)

Aim The correlation of subclinical hypothyroidism (SCH) and polycystic ovary syndrome (PCOS) is a still insufficiently explored entity. The aim of this study was to determine the correlation between SCH and PCOS along with the impact of SCH on metabolic and hormonal parameters in women with PCOS. Methodology This cross-sectional study was conducted at the Gynecology Outpatient Department of Ziauddin Hospital Kemari, Karachi, Pakistan, from June 2019 to December 2019. A total of 90 diagnosed cases of PCOS were enrolled in the study. A non-probability consecutive sampling technique was used. After taking informed consent, participants were evaluated through clinical interviews, a questionnaire, and anthropometric measurements. The participants underwent the following assessments, i.e., transabdominal ultrasonography, hormonal profile (free testosterone, follicle-stimulating hormone, luteinizing hormone), and fasting blood sugar. Participants were divided into two groups based on thyroid-stimulating hormone (TSH) into the euthyroid group and subclinical hypothyroid (SCH) group. The Mann-Whitney test was used for comparing the two groups. Results Our results showed a significant difference in weight, body mass index (BMI), insulin, homeostatic model assessment of insulin resistance (HOMA-IR), and TSH were found in the SCH group as compared to the euthyroid group. A significant correlation of TSH with waist-hip ratio (WHR), weight, body mass index (BMI), insulin, and the homeostatic model assessment of insulin resistance (HOMA-IR) in PCOS patients. Conclusion This study showed a significant correlation of subclinical hypothyroidism with polycystic ovary syndrome. We found subclinical hypothyroidism may aggravate the insulin resistance; therefore, PCOS patients must be screened with a thyroid profile.

Subclinical Hypothyroidism in Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Background: The association between subclinical hypothyroidism (SCH) and polycystic ovary syndrome (PCOS) has been reported in several studies, but it is not well-recognized. The aim of this study was to evaluate the prevalence of SCH in women with PCOS. Methods: An extensive literature search was conducted in PubMed, Embase, Web of Science, and Cochrane Library databases. All articles published before May 2018 was considered for eligibility. No language restrictions were implemented. The prevalence of SCH in PCOS was calculated by the meta-analysis to produce an odds ratio (OR) with 95% confidence interval (CI). Results: A total of 6 studies including 692 PCOS patients and 540 controls were eligible for the meta-analysis. The combined odds ratio (OR) of SCH risk for women with PCOS compared with controls was 2.87 (95% CI = 1.82-9.92; P < 0.000001). The OR increased to 3.59 when limiting thyroid stimulating hormone (TSH) cut-off to ≥4 mIU/L. Conclusions: Women with PCOS are more likely to develop SCH.