This study aims to establish the first county-level, population-based prospective cohort in Taining County, Fujian Province, China. The cohort will include at least 20,000 residents aged 18 years or older. The project will systematically collect questionnaires, physical measurements, laboratory tests, imaging data, and biological samples to build a multi-dimensional health database and biobank. Through 3-year follow-up, the study seeks to reveal the epidemiological patterns and risk factors of chronic diseases, characterize the natural course of multimorbidity and aging syndromes, and develop a comprehensive chronic disease management model suitable for rural and mountainous regions.

China is undergoing rapid population aging, with chronic non-communicable diseases (NCDs) becoming the leading cause of death and disability. Taining County, located in a mountainous area of Fujian Province, faces a higher-than-average aging population and a growing burden of hypertension, diabetes, dyslipidemia, and cardiovascular diseases. Early detection and standardized management remain insufficient, and healthcare resources are limited. This study will establish a prospective cohort covering ≥20,000 residents, integrating demographic, lifestyle, clinical, laboratory, and imaging data. Active follow-up will be conducted annually, complemented by passive follow-up through local healthcare and death registry systems. The study will (1) identify epidemiological features and risk factors of common chronic diseases, (2) explore multimorbidity and aging trajectories, and (3) develop a replicable "Taining Model" for chronic disease prevention and management at the county level. The results will provide an evidence base for public health decision-making and chronic disease control strategies in similar rural and mountainous regions.

Inclusion Criteria:

• Age ≥18 years, male or female.
• Resident of Taining County for ≥6 months and expected to remain in the county for at least the next 3 years.
• Full civil capacity and able to understand study procedures.
• Willing to voluntarily participate and provide written informed consent.
• Able to complete baseline survey and follow-up visits.

Exclusion Criteria:

• Refusal to sign informed consent.
• Severe psychiatric disorders or cognitive impairment preventing participation.
• End-stage disease with expected survival <1 year.
• Long-term migrants (≥6 months per year outside the county), unable to guarantee follow-up.
• Participation in other clinical studies that may interfere with this research.

The study population will consist of community-dwelling adult residents of Taining County, a mountainous region in Fujian Province, China. Eligible participants are men and women aged 18 years and older who have lived in the county for at least 6 months and are expected to remain for the next 3 years.

A total of at least 20,000 participants will be enrolled at baseline through community-based recruitment and household registration systems. The population reflects the demographic and health characteristics of a rural county with a relatively high proportion of older adults and a growing burden of chronic diseases such as hypertension, diabetes, and cardiovascular disease.

De-identified individual participant data, including demographic information, clinical characteristics, imaging parameters ECG data, laboratory test results, biospecimen profiles and follow-up outcomes, will be shared.

IPD will be made available beginning 24 months after the primary study completion date and remain accessible for up to 24 months.

Qualified researchers with a scientifically sound proposal may request access to the data. Requests will be evaluated by the study steering committee. Approved users must sign a data use agreement ensuring compliance with privacy, ethical, and scientific standards.