Objective Polycystic ovary syndrome (PCOS) is associated with insulin resistance and obesity. Prospective population-based data regarding development and possible predictors of type 2 diabetes (T2D) in PCOS are limited. Design National Patient Register–based study. Methods Patients with PCOS [PCOS Denmark and embedded cohort, PCOS Odense University Hospital (OUH)] and a control population with no previous diagnosis of T2D. PCOS OUH (N = 1,162) included premenopausal women with PCOS and standardized clinical and biochemical examination. PCOS Denmark (N = 18,477) included women with PCOS in the Danish National Patient Register. Three age-matched controls were included per patient (N = 54,680). Main outcome T2D events according to diagnosis codes and filled medicine prescriptions. Results The median (quartiles) follow-up was 11.1 (6.9 to 16.0) years. The hazard ratio (HR) with 95% confidence interval (CI) for development of T2D in PCOS Denmark was HR = 4.0 (95% CI, 3.7 to 4.3; P < 0.001), and the total event rate of T2D was 8.0 per 1000 person years in PCOS Denmark vs 2.0 per 1000 person years in controls (P < 0.001). The median age at diagnosis of T2D was 31 (26 to 37) years in PCOS Denmark vs 35 (27 to 44) years in controls (P < 0.001). In multiple regression analyses, body mass index, glycated hemoglobin, fasting blood glucose, 2-hour blood glucose, homeostasis model assessment of insulin resistance, and triglycerides were positively associated with development of T2D, whereas higher number of births was negatively associated with development of T2D. Conclusion The event rate of T2D was higher in PCOS compared with controls, and T2D was diagnosed at a younger age.

Polycystic ovary syndrome (PCOS) is associated with obesity and low grade inflammation and the risk for cardiovascular disease (CVD) could be increased in PCOS. National register-based study including women with PCOS and no previous diagnosis of CVD, hypertension, or dyslipidemia. PCOS Denmark (N = 18,112) included women with PCOS in the Danish National Patient Register. PCOS Odense University Hospital (OUH, N = 1165) was an embedded cohort including premenopausal women with PCOS and clinical and biochemical examination. Three age-matched controls were included per patient in PCOS Denmark (N = 52,769). The main study outcome was CVD events including hypertension and dyslipidemia defined according to nationwide in- and outpatient hospital contact diagnosis codes and/or inferred from filled medicine prescriptions. The age at inclusion was median (quartiles) 29 (23–35) years and follow up was 11.1 (6.9–16.0) years. The Hazard ratio (95% CI) for development of CVD in PCOS Denmark was 1.7 (1.7; 1.8) (P < 0.001) and the total event rate of CVD was 22.6 per 1000 patient years in PCOS Denmark vs. 13.2 per 1000 patient years in controls (P < 0.001). The median age at diagnosis of CVD was 35 (28–42) years in PCOS Denmark vs. 36 (30–43) years in controls (P < 0.001). Obesity, diabetes, and infertility, and previous use of oral contraceptives were associated with increased risk of development of CVD in PCOS Denmark (P < 0.001). Women in PCOS OUH resembled women in PCOS Denmark regarding risk of CVD. Age, BMI, blood pressure, lipid status, and glycemic status predicted development of CVD in PCOS OUH. The event rate of CVD including hypertension and dyslipidemia was higher in PCOS compared to controls. The risk of developing CVD must be considered even in young women with PCOS.

Objective: The prevalence of type 2 diabetes is increased in polycystic ovary syndrome (PCOS), but the prevalence of other diseases is not clarified. We aimed to investigate morbidity and medicine prescriptions in PCOS.Design: A National Register-based study.Methods: Patients with PCOS (PCOS Denmark and an embedded cohort; PCOS Odense University Hospital (OUH)) and one control population. Premenopausal women with PCOS underwent clinical and biochemical examination (PCOS OUH,n=1217). PCOS Denmark (n=19 199) included women with PCOS in the Danish National Patient Register. Three age-matched controls were included per patient (n=57 483).Main outcome measures: Diagnosis codes and filled prescriptions.Results: The mean (range) age of the PCOS Denmark group and controls was 30.6 (12–60) years. Patients in PCOS Denmark had higher Charlson index, higher prevalence of diabetes, dyslipidemia, and hypertension than controls. PCOS was associated with a two times increased risk of stroke and thrombosis, whereas the risk of other cardiovascular diseases was not increased. Thyroid disease, asthma, migraine, and depression were more prevalent in PCOS Denmark vs controls, whereas fractures were rarer. Infertility was increased in patients compared with controls, but the mean number of births was higher in PCOS. Medicine prescriptions within all diagnosis areas were significantly higher in PCOS patients than in controls.In PCOS OUH, polycystic ovaries (PCO) and irregular menses were associated with a more adverse metabolic risk profile, but individual Rotterdam criteria were not associated with cardiometabolic diagnoses.Conclusion: Cardiometabolic and psychiatric morbidity were significantly increased in a Danish population with PCOS. Medical diseases are frequent also in young patients with PCOS.