Background:

Platelets are a type of blood cell that play a critical role in bleeding, forming blood clots, and healing. Researchers want to know more about platelets work in healthy people. They want to look at how platelets clump together, how blood clots, and how genes and proteins work. They also want to study how these processes change over time and how they are affected by factors such diet, exercise, weight, and new health problems.

Objective:

To study how platelets function in healthy people.

Eligibility:

Healthy people aged 18 years and older.

Design:

Researchers will review participants medical history. They will ask about the participant s family history and any drugs they take.

Participants will have a clinic visit once every 6 or 7 months for 10 years. Each visit will be 2 to 3 hours.

At each visit, participants will have several tests and procedures:

A physical exam, including vital signs. Hip and ankle circumference will be measured.

Urine collection.

Blood tests. About 10 tablespoons of blood will be drawn. Participants will be asked to fast for 10 hours and avoid drugs like aspirin or Advil for 7 days before each draw. Some of the blood may be used for gene studies. Some may be used to create stem cells for research. Stem cells are cells that can be used to make other types of cells.

Surveys and questionnaires. Participants will answer questions about habitual activity, diet, smoking, drugs and alcohol, sleep, illness, and other health issues. These surveys may be done online, via email, or by phone.

Study Description:

This study will serve to provide tissue samples from healthy volunteers for mechanistic studies of platelet function.

Objectives:

Primary Objective: The goal is to obtain blood samples and corresponding derived information to optimize assays, understand variation in these assays due to different sources of variation, and conduct statistical association studies with appropriate designs including cross-sectional analysis, and longitudinal analyses. Environmental variables may include health reports, anthropometric variables, questions on habits and risk factors and medication during the study.

Endpoints:

Primary Endpoints: Establish and validate technical assays and equipment (e.g. platelet aggregation, hemostasis measurements, methylation, RNA-seq, proteomics and WGS, in vitro iPSC generation and bench compound and cellular imaging screening, etc.)

Establish normal physiologic mechanisms and platelet-related parameters in healthy participant samples and how these vary longitudinally and are influenced by variables (e.g., reproducibility, fluctuation with changing diet, exercise, weight and other risk factors or new disease onset)

• INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

• Stated willingness to comply with all study procedures, including fasting at least 10 hours before each blood draw
• Stated willingness to refrain from aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) for 7 days prior to any visits
• Age >= 18 years
• In good general health as evidenced by self-reported medical history

EXCLUSION CRITERIA:

An individual who, by self-report, meets the following criteria will be excluded from participation in this study:

• Current pregnancy or lactation
• Active malignancies known, active known auto-immune disease, known major CVD (e.g., heart attack, stroke, venous thromboembolism, heart failure), severe bleeding history, on regular P2Y12 inhibitors or other antiplatelet treatments for a clinical reason, uncontrolled hypertension or diabetes

Healthy participants, at least 18 years of age

See DMSP

Data will be made available at the time of associated publication and the duration of availability is expected to be indefinite but will ultimately be determined by the NHLBI.

Clinical and laboratory data will be collected in the electronic data capture system (CTDB) and analyzed using open-source statistical software packages. Some lab-based research data is collected on specialized instruments and custom processing programs are used to summarize/QC. Those scripts will not be shared unless requested.@@@@@@Data sharing for clinical study (PVLMO)@@@Will be via a separate study accession in dbGaP. Summary level data such as GWAS summary statistics or gene expression level means may be deposited in appropriate public repositories such as NCBI GeoDatasets or the NHLBI GRASP GWAS portal.@@@