Temporal trends in the prevalence of polycystic ovary syndrome in China from 1990 to 2021, and projections until 2036: a comparison with Japan, Asia, and global level

Background: The burden of polycystic ovary syndrome is increasing worldwide, which places a heavy burden on society and healthcare systems. This study investigates the independent effects of age, period, and cohort on the polycystic ovary syndrome prevalence from 1990 to 2021 in China, Japan, Asia and World. And then predicts the future burden of polycystic ovary syndrome over the next decade. Method: The data were collected from the Global Burden of Disease (GBD) 2021 study, and the average annual percent change (AAPC) and relative risks (RRs) analyzed by joinpoint regression and APC-IE model. And this study employed the BAPC model to predict future disease burdens in China and Japan. Results: In 2021, there were 533.533*104 (95%CI:376.054*104, 750.101*104) cases of PCOS in China, accounting for 28.69% of all cases in Asia and 14.56% globally. The ASPR of PCOS in China increased from 1990 to 2021, with an AAPC of 2.01 (95%CI: 1.99,2.03), which was significantly higher than that of Japan (0.21; 95%CI: 0.20,0.22), Asia (1.30; 95%CI: 1.28,1.31) and the global average (0.81; 95%CI: 0.80,0.82)). The age-period-cohort analyses revealed that the relative risk (RR) of polycystic ovary syndrome increased with age, peaking at 20–24 years in Chinese women (RR = 1.591) and Japan women (RR=1.64). And Japan showed a slight increase in the 35-39 age group (RR=1.583). The period effect of polycystic ovary syndrome showed a consistent upward trend in China, Japan, Asia, and globally. And China experienced the most substantial increase from 1992-1996 (RR=0.701) to 2017-2021 (RR=1.271). The cohort effect of PCOS demonstrated a declining trend across regions, but China and Asia experienced an incline from 2002-2006 to 2007-2011 birth cohort. By 2036, the ASPR of PCOS in China is projected to increase by 27% from 2021, reaching 1961.45/100,000. Conclusions: The prevalence of the PCOS in China has increased significantly over the past three decades. The age group with a high prevalence of polycystic ovary syndrome among Chinese women is 20-25 years old. And women in the new birth cohort are more likely to develop polycystic ovary syndrome. It is imperative that the government standardize the diagnosis and treatment of polycystic ovary syndrome and provide health education to the women.