Age-Adjusted Prevalence and Characteristics of Women with Polycystic Ovarian Syndrome in Korea: A Nationwide Population-Based Study (2010-2019)

Prospective risk of Type 2 diabetes in 99 892 Nordic women with polycystic ovary syndrome and 446 055 controls: national cohort study from Denmark, Finland, and Sweden

STUDY QUESTION

What is the prospective risk of Type 2 diabetes (T2D) in Nordic women with polycystic ovary syndrome (PCOS) compared to controls?

SUMMARY ANSWER

A diagnosis of PCOS and BMI ≥30 kg/m2 is a high-risk phenotype for a prospective risk of T2D diagnosis across Nordic countries.

WHAT IS KNOWN ALREADY

The risk of T2D in women with PCOS is increased. The risk of T2D is related to BMI and the magnitude of risk in normal weight women with PCOS has been discussed. However, prospective data regarding risk of T2D in population-based cohorts of women with PCOS are limited.

STUDY DESIGN, SIZE, DURATION

This national register-based study included women with PCOS and age-matched controls. The main study outcome was T2D diagnosis occurring after PCOS diagnosis. T2D was defined according to ICD-10 diagnosis codes and/or filled medicine prescriptions of anti-diabetic medication excluding metformin.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study cohort included women originating from Denmark (PCOS Denmark, N = 27 016; controls, N = 133 994), Finland (PCOS Finland, N = 20 467; controls, N = 58 051), and Sweden (PCOS Sweden, N = 52 409; controls, N = 254 010). The median age at cohort entry was 28 years in PCOS Denmark, Finland, and Sweden with a median follow-up time (interquartile range) in women with PCOS of 8.5 (4.0-14.8), 9.8 (5.1-15.1), and 6.0 (2.0-10.0) years, respectively. Cox regression analyses were adjusted for BMI and length of education.

MAIN RESULTS AND THE ROLE OF CHANCE

The crude hazard ratio (HR, 95% CI) for T2D diagnosis in women with PCOS was 4.28 (3.98-4.60) in Denmark, 3.40 (3.11-3.74) in Finland, and 5.68 (5.20-6.21) in Sweden. In adjusted regression analyses, BMI ≥30 vs <25 kg/m2 was associated with a 7.6- to 11.3-fold risk of T2D. In a combined meta-analysis (PCOS, N = 99 892; controls, N = 446 055), the crude HR for T2D in PCOS was 4.64 (3.40-5.87) and, after adjustment for BMI and education level, the HR was 2.92 (2.32-3.51).

LIMITATIONS, REASONS FOR CAUTION

Inclusion of more severe cases of PCOS in the present study design could have lead to an overestimation of risk estimates in our exposed population. However, some women in the control group would have undiagnosed PCOS, which would lead to an underestimation of T2D risk in women with PCOS. BMI data were not available for all participants. The present study should be repeated in study cohorts with higher background risks of T2D, particularly in populations of other ethnicities.

WIDER IMPLICATIONS OF THE FINDINGS

The prospective risk for diagnosis of T2D is increased in women with PCOS, and the risk is aggravated in women with BMI ≥30 kg/m2.

STUDY FUNDING/COMPETING INTEREST(S)

Funding in Denmark was from the Region of Southern Denmark, Overlægerådet, Odense University Hospital. Funding in Finland was from Novo Nordisk Foundation, Finnish Research Council and Sigrid Juselius Foundation, the National Regional Fund, Sakari Alhopuro Foundation and Finnish Diabetes Research Foundation. E.E. has received a research grant from Ferring Pharmaceuticals (payment to institution) and serves as medical advisor for Tilly AB, not related to this manuscript. The remaining authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

The diverse influences of relaxin-like peptide family on tumor progression: Potential opportunities and emerging challenges

Relaxin-like peptide family exhibit differential expression patterns in various types of cancers and play a role in cancer development. This family participates in tumorigenic processes encompassing proliferation, migration, invasion, tumor microenvironment, immune microenvironment, and anti-cancer resistance, ultimately influencing patient prognosis. In this review, we explore the mechanisms underlying the interaction between the RLN-like peptide family and tumors and provide an overview of therapeutic approaches utilizing this interaction.

Pregnancy complications and endometrial cancer in women with polycystic ovarian syndrome: a Korean National Health Insurance Service study

OBJECTIVE

Polycystic ovarian syndrome is associated with diverse pregnancy related complications and endometrial cancer. However, research on the relationship between pregnancy complications and endometrial cancer in women with polycystic ovarian syndrome is scarce. We aimed to examine the association between gestational diabetes mellitus, pregnancy induced hypertension, and preterm birth and the risk of endometrial cancer in women with polycystic ovarian syndrome.

METHODS

We analyzed data from the National Health Information Database established by the Korean National Health Insurance Service between January 2002 and December 2019. We included women with gestational diabetes mellitus, pregnancy induced hypertension, preterm birth, and endometrial cancer from among the polycystic ovarian syndrome population. All conditions were diagnosed according to the Korean Informative Classification of Diseases, 10th revision codes. Age, area of residence, income, body mass index, waist circumference, total cholesterol, high density lipoprotein, low density lipoprotein, triglycerides, fasting blood sugar, and creatinine levels were included as covariates in the multiple logistic regression analysis.

RESULTS

Of 467 221 women with polycystic ovarian syndrome included, 5099 had endometrial cancer. Age, residence, income, body mass index, waist circumference, total cholesterol, high density lipoprotein, low density lipoprotein, triglycerides, fasting blood sugar, and creatinine levels differed significantly between the endometrial cancer and non-endometrial cancer groups (p≤0.001-0.032). Among the polycystic ovarian syndrome population, the odds ratios (ORs) of endometrial cancer were 1.50, 1.43, and 1.23 in women with a history of gestational diabetes mellitus, pregnancy induced hypertension, and preterm birth, respectively, compared with those without a history of these conditions (OR 1.50, 95% confidence interval (CI) 1.32 to 1.69, p<0.001; 1.43, 1.04 to 1.97, p=0.027; and 1.23, 1.05 to 1.45, p=0.011, respectively).

CONCLUSION

Our results suggest that a history of pregnancy complications (gestational diabetes mellitus, pregnancy induced hypertension, and preterm birth) increases the risk of endometrial cancer in women with polycystic ovarian syndrome.

Effects of Exposure Duration and Exposure Levels of Ambient Air Pollutants on the Risk of Polycystic Ovarian Syndrome: A 2015-2019 Korean Population-Based Cohort Study

Exposure to ambient air pollution is associated with an increased risk of menstrual disorders and infertility. This study examined the relationships between the levels and duration of air pollution exposure and the risk of polycystic ovarian syndrome (PCOS) using Korean population-based cohort data (2015-2019). Real-time data on PM₁₀, PM_2.5, O₃, CO, SO₂, and NO₂ were provided by the Korean Ministry of Environment. The average monthly air pollutant concentration from 1 January 2014 to 31 December 2018 was analyzed. To assess individual-level exposure to air pollutants, a spatial prediction model and an area-averaging approach were used. In total, 237,582 PCOS cases were analyzed. The annual age-adjusted PCOS incidence was 6.70, 8.28, 9.73, 11.58, and 11.97% from 2015-2019, respectively. The PCOS risk increased 1.29-1.32, 1.43-1.52, and 1.32-fold following exposure to the 2-year and 3-year average levels of PM_2.5, O₃, and NO₂, respectively, compared to their 1-year average levels. The PCOS risk increased 1.75-fold (95% confidence interval: 1.66-1.85) in the fourth-quartile for the NO₂ level. Increased SO₂ and CO levels in the second- and third-quartiles were also associated with an increased PCOS risk. Exposure to air pollutants thus increased the risk for PCOS in the Korean population.