The purpose of this study is to examine the natural history and risk factors of osteoarthritis (OA) and to explore the relationship between metabolic factors and OA progression.

1. To investigate the natural history of osteoarthritis (OA) in a large-sample cohort.
2. To identify OA phenotypes and their relationship with clinical symptoms and functional impairment.
3. To analyze metabolic factors (e.g., obesity, diabetes, and hypertension) as risk factors for OA onset and progression.
4. To evaluate the association between radiographic changes and OA symptoms.
5. To develop predictive models for OA progression and identify high-risk individuals for early intervention.

Design: This is a prospective cohort study. Participants: The study will recruit approximately 4,000 individuals aged 50 years and above. Participants will undergo baseline assessments, including demographic data collection, medical history, dietary evaluation, physical examination, blood sample collection, and radiographic imaging. Annual follow-ups will be conducted over 10 years to monitor OA progression and related risk factors.

Inclusion Criteria:

• Aged 50 years and above
• Long-term resident of the study area
• Willing to participate and provide informed consent

Exclusion Criteria:

• Hearing, speech, or mental impairments preventing effective communication
• Unable to complete scheduled follow-up visits
• Pregnant or planning pregnancy during the study period
• Any other condition deemed unsuitable for participation by the researchers

This study will include adults aged 50 years and above to investigate osteoarthritis risk factors and progression in a general population-based cohort.