1. To establish a standardized, normalized and scientific joint screening and follow-up management system for chronic disease multimorbidity in Lishui City, and early identify common risk factors of major chronic diseases such as cardiovascular and cerebrovascular diseases and tumors.
2. To carry out targeted intervention and long-term follow-up for high-risk populations, reduce the incidence risk of major chronic diseases in the target population, improve residents' health status and grassroots comprehensive prevention and treatment capacity of chronic diseases, and provide scientific evidence and practical support for the construction of Healthy Lishui.

This project will establish a cohort related to stroke and tumors, with 4500 subjects selected from the 30-80-year-old urban-rural integrated population in Lishui City, covering both urban and rural residents in the urban-rural junction area of the region. This population, with diverse living habits and uneven access to medical resources, is a key group for the prevention and control of stroke and tumors, and its selection can reflect the epidemiological characteristics of the two diseases in Lishui.

To achieve the research goal, the subjects will be randomly divided into three groups for targeted detection, with specific schemes as follows:

Group A: Magnetic Resonance (MR) examination (focusing on the head and neck to identify cerebrovascular and tissue abnormalities) and methylation pan-cancer detection (non-invasive and high-sensitivity, used to screen for early methylation abnormal changes of tumor-related genes).

Group B: Methylation pan-cancer detection (consistent with Group A), Transcranial Doppler (TCD) examination (for intracranial hemodynamic monitoring), cervical ultrasound (for assessing cervical artery conditions), and Vibration-Controlled Transient Elastography (VCTE) examination (for detecting liver elasticity).

Group C: Physiological age methylation detection (evaluating the real physiological aging state through the methylation level of age-related CpG sites) and VCTE examination (consistent with Group B) to supplement liver function-related detection.

The core purpose of this project is to explore the three-dimensional distribution (time, place, and population distribution) of stroke and tumors in this population. Time distribution aims to explore the variation rules of incidence rates across different seasons, years, and age stages; regional distribution aims to analyze the differences in incidence rates among different urban-rural junctions and their correlation with environmental and medical resource factors; population distribution aims to identify high-risk groups by analyzing the differences in incidence rates among different genders, ages, living habits, and physiological aging states.

In addition, this project will clarify the correlation between each detection indicator and the two diseases, improve the construction of biological sample banks and databases, provide a scientific basis for establishing a community-hospital linked intervention system, thereby improving the early detection rate and intervention rate of diseases and protecting the health of residents

Inclusion Criteria:

• Aged 30 to 80 years old; male-to-female ratio of 1:1; permanent residents in Lishui City; physically healthy; voluntary participation in the project with signed informed consent.

Exclusion Criteria:

• Individuals ever diagnosed with malignant tumors or cardiovascular and cerebrovascular diseases by physicians or other health professionals; those with unstable vital signs or an expected survival time of less than 3 months; participants with incomplete basic information, and those unable to cooperate with subsequent follow-up.

The study population consists of 4,500 participants aged 30-80 years recruited from 10 urban and 10 rural sites in Lishui City using a cluster sampling method. Participants are randomly divided into three equal groups of 1,500 each, receiving different examination protocols. The collected data are further analyzed and grouped into cerebrovascular, tumor, and epigenetic age categories based on the respective test results.

The individual participant data (IPD) for this study will not be shared publicly due to concerns regarding participant privacy, data security, and the lack of an established data sharing agreement and platform. All data are stored and managed in accordance with applicable data protection regulations and institutional policies.