What is the goal of the FHS?
The NHLBI has a long history of supporting large population and epidemiology studies that have transformed the way the public approaches heart disease. These studies involve studying the health of various populations to uncover patterns, trends, and outcomes that may be applicable to the general population. When it launched in 1948 the original goal of the Framingham Heart Study (FHS) was to identify common factors or characteristics that contribute to cardiovascular disease. Over the years, the FHS has become a successful, multigenerational study that analyzes family patterns of cardiovascular and other diseases, while gathering more genetic information from the two generations that followed the original study participants. The FHS also has expanded to include diverse populations so that risk factors in these different groups can be understood.
- The FHS had over 14,000 people from three generations, including the original participants, their children, and their grandchildren.
- FHS findings have informed the understanding of how cardiovascular health affects the rest of the body.
- The study found high blood pressure and high blood cholesterol to be major risk factors for cardiovascular disease.
- In the past half century, the study has produced approximately 3,000 articles in leading medical journals.
- Data resources from the study are available for researchers to use, and those data continue to spur new scientific discoveries.
What are the key findings of the FHS?
This research has contributed transformative discoveries related to the treatment of heart disease. Through the FHS, scientists have learned the risk factors for heart disease, and they now know that many of those risks can be changed. It is why, in routine physicals, doctors check for high blood pressure, high cholesterol, unhealthy eating patterns, smoking, physical inactivity, or unhealthy weight. Researchers also know that these conditions can affect people differently depending on a patient’s sex or race. Findings such as these pave the way for new interventions to preempt, prevent, or treat these conditions more effectively.
In the past half century, the study has produced approximately 3,000 articles in leading medical journals. Here are a few of the major findings from the FHS:
- 1960s: Cigarette smoking was found to increase the risk of heart disease, and cholesterol level, blood pressure, and electrocardiogram abnormalities were found to increase the risk of heart disease.
- 1970s: High blood pressure was found to increase the risk of stroke; atrial fibrillation was found to increase stroke risk five-fold; and menopause was found to increase the risk of heart disease.
- 1980s: High levels of HDL cholesterol were found to reduce risk of death.
- 1990s: An enlarged left ventricle, one of two lower chambers of the heart, was shown to increase the risk of stroke.
- 2000s: Prehypertension was associated with an increased risk of cardiovascular disease, emphasizing the need to determine whether lowering high-normal blood pressure can reduce the risk of cardiovascular disease
- 2010s: Sleep apnea was tied to an increased risk of stroke; FHS researchers identified additional genes that may play a role in Alzheimer's disease; study investigators discovered hundreds of genes underlying major heart disease risk factors.
Since its early days, the FHS has been committed to data sharing. In 1968, the FHS made massive data tables of FHS-collected measures freely available to outside researchers, many of whom lacked computing resources. NHLBI has continued to leverage FHS resources to spur new scientific discovery through data sharing.
- The NHLBI is using FHS data in the TOPMed Program to better understand the genetic and environmental factors contributing to cardiovascular disease.
- Study datasets from the FHS, including cohort examination data from the first 30 clinical exams, are available for request via NHLBI’s Biologic Specimen and Data Repositories Information Coordinating Center (BioLINCC).
- Researchers also can request FHS genetic data, along with information about major disease risk factors (e.g., systolic blood pressure, cholesterol levels, cigarette use), in the database of Genotypes and Phenotypes (dbGaP).
How is the FHS conducted?
When the FHS began in 1948, researchers recruited 5,209 men and women between the ages of 30 and 62 from the town of Framingham, Massachusetts. This was for the first round of extensive physical examinations and lifestyle interviews they would later analyze for common patterns related to cardiovascular disease development. Since then, the participants have continued to return to the study approximately every two to six years to give researchers a detailed medical history and to get physical exams and laboratory tests done. In 1971, the study enrolled a second generation—5,124 of the original participants' adult children and their spouses—to participate in similar examinations. In April 2002, the study entered a new phase: the enrollment of a third generation of participants, the grandchildren of the original cohort.
Researchers recognized the need to establish a new study reflecting Framingham’s more diverse communities. In 1994 they enrolled the first Omni Cohort of the Framingham Heart Study—507 men and women of African-American, Hispanic, Asian, Indian, Pacific Islander, and Native American descent. In 2003, a second group of Omni participants was enrolled.