Prevalence and Associated Risk Factors of Osteoporosis in Community-Dwelling Older Adults in China: A Cross-Sectional Study of 2533 Participants.

BACKGROUND Osteoporosis poses a growing public health challenge in China's rapidly aging population. However, updated epidemiological data on osteoporosis prevalence and risk factors among community-dwelling older adults remain limited. This study aimed to investigate the prevalence of osteoporosis and identify its associated risk factors in community-dwelling older people in Eastern China. MATERIAL AND METHODS A community-based cross-sectional study was conducted among 2533 adults aged 65 years and older in Hangzhou, China, between February and December 2023. Bone mineral density at the lumbar spine, femoral neck, and total hip was measured using dual-energy X-ray absorptiometry. Osteoporosis was defined as a T score ≤-2.5 at any site according to WHO criteria. Demographic characteristics, lifestyle factors (smoking, alcohol consumption, physical activity), and medical history (diabetes, hypertension) were collected through standardized questionnaires. Multivariable logistic regression was employed to identify independent risk factors for osteoporosis. RESULTS The overall prevalence of osteoporosis was 32.8% (95% CI: 31.0%-34.6%), with significantly higher prevalence in women than in men (48.3% vs 15.2%, P<0.001). Prevalence increased progressively with age, from 24.6% in those aged 60 to 69 years to 45.7% in those aged ≥80 years (P for trend <0.001). Multivariable analysis revealed that female sex (OR=4.82, 95% CI: 3.91-5.94), advanced age (OR=1.58 per 10-year increase, 95% CI: 1.38-1.81), low body mass index (BMI <18.5 kg/m²; OR=2.36, 95% CI: 1.58-3.52), and physical inactivity (OR=1.54, 95% CI: 1.18-2.01) were independently associated with increased osteoporosis risk. Diabetes and hypertension showed no significant association after multivariable adjustment. CONCLUSIONS Osteoporosis affects nearly one-third of community-dwelling older adults in Eastern China, with particularly high burden among women and the oldest-old. Low BMI and physical inactivity emerged as important modifiable associated factors. These findings suggest potential targets for communitybased screening and lifestyle programs, although causal inferences cannot be drawn from this crosssectional design.