Prevalence of osteoporosis and associated factors among Chinese adults: a systematic review and modelling study.

Background: Osteoporosis is a degenerative disease of bone metabolism. The epidemiology of osteoporosis varies by age, sex, and geography. There is a lack of information on the prevalence of osteoporosis among Chinese adults. In this study, we aimed to estimate the prevalence of osteoporosis among Chinese adults by age, sex, and skeletal sites and explore the main associated factors. Methods: We searched six bibliographic databases to identify epidemiological studies that reported the prevalence of osteoporosis among Chinese adults published between January 1990 and February 2022. We applied a multilevel mixed-effects meta-regression to estimate the age-specific prevalence of osteoporosis. We presented the age-specific prevalence of osteoporosis by sex, diagnostic criteria (World Health Organization (WHO) and Chinese (CHN) diagnostic criteria), and specific skeletal site (the lumbar spine, femoral neck, and ward's triangle). We used the population data from the seventh National Census of Mainland China to estimate the number of Chinese adults with osteoporosis in 2020. Major associated factors for osteoporosis were pooled by a random-effects meta-analysis. We also estimated the regional prevalence and cases of osteoporosis among 31 provinces in mainland China in 2020 using an 'associated factor-based model.' Results: We included 129 articles in this systematic review and modelling study. 32 were based on the WHO diagnostic criteria and 17 on the CHN diagnostic criteria. Additionally, we included 83 articles in the associated factor analysis. The prevalence of osteoporosis increased with age and was consistently higher in females than males, regardless of diagnostic criteria and skeletal sites. Whether based on the WHO criteria (13.54%, 95% confidence interval (CI) = 10.25, 18.11) or the CHN criteria (29.49%, 95% CI = 18.29, 43.5), the prevalence of osteoporosis among Chinese adults aged 20-89 years in 2020 was highest when measuring the ward's triangle, which translated to 145.86 million (95% CI = 110.41, 195.03) and 317.54 million (95% CI = 196.95, 468.47) affected adults, respectively. The prevalence of osteoporosis was the highest in Northeast China under both the WHO criteria (15.50%, 95% CI = 11.78, 20.59) and the CHN criteria (32.36%, 95% CI = 20.33, 46.8), with the ward being the measured skeletal site. Marital status, current smoking, underweight, hypertension, fracture history, longer menopause years and menopause were positively associated with osteoporosis. Conclusions: Osteoporosis remains a significant public health concern in China, particularly among females and the elderly. Meanwhile, the prevalence of osteoporosis varies considerably by region, skeletal site and diagnostic criteria. It is essential to establish clear and unified diagnostic criteria and implement high-quality epidemiological studies for osteoporosis in China. Additionally, targeted preventive strategies that focus on individuals with characteristics associated with osteoporosis are required to mitigate the impact of this condition. Registration: PROSPERO: CRD42024564441.