Accelerated osteoarthritis in women with polycystic ovary syndrome: a prospective nationwide registry-based cohort study

BACKGROUND: Osteoarthritis (OA) is the most common form of arthritis with multiple risk factors implicated including female sex and obesity. Metabolic dysregulation associated with obesity leading to metabolic syndrome is a proposed component of that association. Polycystic ovary syndrome (PCOS) commonly affects women of reproductive age and these women are at higher risk of developing metabolic syndrome and thus likely to represent a high-risk group for early OA development. There are no published studies exploring the epidemiology of knee, hip and hand OA in women diagnosed with PCOS. STUDY AIM: To assess the prevalence and incidence of knee, hip and hand osteoarthritis (OA) in women with polycystic ovary syndrome (PCOS) when compared with age-matched controls. METHODS: Prospective Danish national registry-based cohort study. The prevalence of OA in 2015 and incidence rates of OA over 11.1 years were calculated and compared in more than 75,000 Danish women with either a documented diagnosis of PCOS ± hirsutism (during the period of 1995 to 2012) or age-matched females without those diagnoses randomly drawn from the same population register. RESULTS: In 2015, the prevalence of hospital treated knee, hip and hand OA was 5.2% in women with PCOS diagnosis. It was 73% higher than that seen in age-matched controls. Significantly higher incidence rates were observed in the PCOS cohort compared with the age-matched controls during the follow-up period (up to 20 years), with the following hazard ratios (HR): 1.9 (95% CI 1.7 to 2.1) for knee, 1.8 (95% CI 1.3–2.4) for hand and 1.3 (95% CI 1.1 to 1.6) for hip OA. After excluding women with obesity, similar associations were observed for knee and hand OA. However, risk of developing hip OA was no longer significant. CONCLUSIONS: In this large prospective study, women with PCOS diagnosis had higher prevalence and accelerated onset of OA of both weight and non-weight bearing joints, when compared with age-matched controls. Further studies are needed to understand the relative effect of metabolic and hormonal changes linked with PCOS and their role in promoting development of OA. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13075-021-02604-w.