Increased prospective cardiovascular disease risk in 127 517 Nordic women with polycystic ovary syndrome: a national cohort study

BACKGROUND: Cardiovascular disease (CVD) risk factors are prevalent in women with polycystic ovary syndrome (PCOS), but prospective data regarding CVD in population-based cohorts are limited. AIM: This study aims to investigate prospective risk of CVD in Nordic women with PCOS. DESIGN: This is a national register-based study in women with PCOS and age-matched controls originating from Denmark (PCOS Denmark, N = 27 298, controls, N = 135 019), Finland (PCOS Finland, N = 20 765, controls, N = 59 122), and Sweden (PCOS Sweden, N = 79 454, controls, N = 393 669). The main study outcome was CVD. Cardiovascular disease was defined according to ICD-10 diagnostic codes for major adverse cardiac events, pulmonary embolism, and/or deep venous thrombosis. Cox regression analyses estimated hazard ratio (HR) with 95% CI and adjusted analyses included body mass index (BMI) and education. RESULTS: The median age at cohort entry was 28 years (Denmark) and 29 years (Finland and Sweden) and the median follow-up time was 8.0-10.0 years. The unadjusted HR (95% CI) for CVD in women with PCOS was 1.30 (1.20; 1.41) in Denmark, 1.45 (1.31; 1.60) in Finland, and 1.52 (1.44; 1.60) in Sweden. Models remained significant after adjusting for obesity and level of education. In a combined meta-analysis including all countries (PCOS, N = 127 517, controls, N = 587 810), the adjusted HR for CVD in women with PCOS was 1.32 (1.25; 1.39). In women with BMI < 25 kg/m2 and no type 2 diabetes, the adjusted HR for CVD risk was 1.40 (1.26; 1.55). CONCLUSION: The risk of CVD was increased in women with PCOS across the 3 Nordic countries, also among women with BMI < 25 kg/m2.