Investigating the causal impact of polycystic ovary syndrome on gestational diabetes mellitus: a two-sample Mendelian randomization study

Front Endocrinol (Lausanne). 2024 Feb 5:15:1337562. doi: 10.3389/fendo.2024.1337562. eCollection 2024.

Abstract

Introduction: Determining the causal relationship between polycystic ovary syndrome (PCOS) and gestational diabetes mellitus (GDM) holds significant implications for GDM prevention and treatment. Despite numerous observational studies suggesting an association between PCOS and GDM, it remains unclear whether a definitive causal relationship exists between these two conditions and which specific features of PCOS contribute to increased incidence of GDM.

Methods: The causal relationship between polycystic ovary syndrome (PCOS), its characteristic indices, and gestational diabetes mellitus (GDM) was investigated using a two-sample Mendelian randomization study based on publicly available statistics from genome-wide association studies (GWAS). The inverse-variance weighted method was employed as the primary analytical approach to examine the association between PCOS, its characteristic indices, and GDM. MR Egger intercept was used to assess pleiotropy, while Q values and their corresponding P values were utilized to evaluate heterogeneity. It is important to note that this study adopts a two-sample MR design where PCOS and its characteristic indices are considered as exposures, while GDM is treated as an outcome.

Results: The study results indicate that there is no causal relationship between PCOS and GDM (all methods P > 0.05, 95% CI of OR values passed 1). The IVW OR value was 1.007 with a 95% CI of 0.906 to 1.119 and a P value of 0.904. Moreover, the MR Egger Q value was 8.141 with a P value of 0.701, while the IVW Q value was also 8.141 with a P value of 0.774, indicating no significant heterogeneity. Additionally, the MR Egger intercept was 0.0004, which was close to zero with a P value of 0.988, suggesting no pleiotropy. However, the study did find a causal relationship between several other factors such as testosterone, high-density lipoprotein, sex hormone-binding globulin, body mass index, waist-hip ratio, apolipoprotein A-I, number of children, diabetes illnesses of mother, father and siblings, hemoglobin A1c, fasting insulin, fasting blood glucose, years of schooling, and GDM based on the IVW method.

Conclusion: We observed no association between genetically predicted PCOS and the risk of GDM, implying that PCOS itself does not confer an increased susceptibility to GDM. The presence of other PCOS-related factors such as testosterone, high-density lipoprotein, and sex hormone-binding globulin may elucidate the link between PCOS and GDM. Based on these findings, efforts aimed at preventing GDM in individuals with PCOS should prioritize those exhibiting high-risk features rather than encompassing all women with PCOS.

Keywords: Mendelian randomization study; causal effects; genome-wide association studies; gestational diabetes mellitus; polycystic ovary syndrome.

MeSH terms

  • Child
  • Diabetes, Gestational* / genetics
  • Female
  • Genome-Wide Association Study
  • Humans
  • Lipoproteins, HDL
  • Mendelian Randomization Analysis
  • Polycystic Ovary Syndrome* / complications
  • Polycystic Ovary Syndrome* / genetics
  • Pregnancy
  • Sex Hormone-Binding Globulin
  • Testosterone

Substances

  • Sex Hormone-Binding Globulin
  • Lipoproteins, HDL
  • Testosterone

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was facilitated by funding from the Research on the Intervention Effect of Multidisciplinary Joint Lifestyle on PCOS Patients under the Background of Internet + Medicine, No. F202103—Lianyungang Maternal and Child Health Research Project; Research on the Impact of Environmental and Behavioral Factors on Embryonic Development and Pregnancy Based on Internal and External Exposure Monitoring, SQ2018YFC100274—National Key Program R&D Key Special Project (Research on Reproductive Health and Prevention and Control of Major Birth Defects); Clinical Precision Diagnosis and Treatment of Spermatogenesis and Developmental Disorders Based on Systematic Analysis of Genetic and Environmental Factors in Huaihai Region, KC22096—Xuzhou City 2022 Special Project for Promoting Scientific and Technological Innovation. Research on the cutoff value of anti-β 2-glycoprotein in adverse pregnancy events among women of childbearing age in Lianyungang area (QN202120)---Youth Talent Training Fund Project. None of these funding bodies partook in the design of the research, data collection and analysis, decision to publish, or manuscript preparation.