The Framingham Heart Disease Epidemiology Study was launched to help physicians better understand heart disease. The study was conducted under the direction of the National Heart Institute, which is currently known as the National Heart, Lung and Blood Institute (NHLBI).

In the study, researchers examined the lives and habits of ordinary people living in a suburban Boston town called Framingham. The purpose was to determine whether a connection existed between an individual’s lifestyle and cardiovascular disease. Researchers investigated the risk factors that people were born with (genetic factors) and those they were exposed to (environmental factors), to determine their effect on the development of heart problems.

Since the original 5,209 participants were enrolled in the Framingham Study, several offspring generations and more ethnically diverse populations have been included in the study. Over 10,000 Framingham residents have now participated, and more than 1,000 scientific papers have been published from the study. Research is expected to continue throughout future generations.

The Framingham Heart Disease Epidemiology Study is a landmark study of the factors that contribute to the development of heart disease. Beginning in 1948, the study has been following the same group of 5,209 adult volunteers from Framingham, Massachusetts. By keeping track of which people develop heart-related diseases, and which do not, vital information related to diet and lifestyle was revealed for the first time. This study is largely responsible for why Americans have become so conscious of the amount of fat in their food and the need for regular exercise.

The study is and has been run by what is now known as the National Heart, Lung and Blood Institute (NHLBI), as well as local universities, physicians and scientists. Before the study, it was widely believed that heart disease was an inevitable result of genetics and aging. Scientists believed it was natural for blood pressure to rise with age as the heart was forced to pump blood through narrowing arteries. The study’s findings were among the first to establish a connection between lifestyle choices and a person’s heart disease risk level. In fact, the term risk factor was coined by Framingham researchers as a direct result of their findings. The Framingham study was instrumental in our modern understanding of how cholesterol levels, smoking, obesity and diabetes contribute to heart disease.

Using data from the Framingham study, researchers were able to create the widely used coronary risk profile worksheet. This simple worksheet uses a few inputs, such as cholesterol levels, blood pressure, diabetes status, and smoking status, to calculate a person's 10-year risk of suffering from some form of heart disease, including angina, heart attack or coronary artery disease. The algorithms used to create this worksheet were developed by looking the population of the study itself. One drawback to this approach is that the Framingham population is almost exclusively white, meaning that these risk calculations might not fit other populations as well. Nevertheless, the Framingham coronary risk profile can provide important information to both patients and physicians.

In the 1940s, heart disease was the number one killer of Americans. To understand why, the U.S. Public Health Service launched a study to examine the nature and causes of heart disease. They decided to follow the lives and habits of ordinary people living in a Boston suburb called Framingham to determine whether there was any connection between the way they lived and the health of their hearts. Their original goal was to investigate the factors people were born with (genetic factors) and those they were exposed to (environmental factors) and see how each contributed to the development of heart disease.

The study began on September 27, 1948. Healthy adult participants between the ages of 30 and 60 volunteered, and a total of 5,209 men and women agreed to take part in the study. All participants were given a thorough physical examination and answered detailed questions about their family medical history and lifestyle. Every two years, participants were given a physical examination and a variety of tests, including blood tests, electrocardiograms (EKGs) and blood pressure readings.

Later, the most modern heart tests (e.g., echocardiograms) were also added to the protocol to provide the researchers with complete “benchmark” data on each participant. Information was also obtained from hospital admission records, death reports and local physicians. Eventually, the study was taken over by the National Heart Institute, which is now known as the National Heart, Lung and Blood Institute (NHLBI).

In 1971, 5,124 children (and their spouses) of the original study participants were enrolled in the study. This has revealed important data in the 1990s and has been called the Framingham Offspring Study. A third generation (children of the Offspring Study) is currently being recruited for continuation of the study. Researchers are hoping to enroll 3,500 grandchildren of the original group. Like previous participants, these individuals will undergo an extensive cardiovascular assessment.

One major flaw with the original study was the lack of ethnic diversity. The participants are almost entirely white (Caucasian). In the late 1990s, researchers recruited 500 African-Americans, Asian-Americans, Native Americans and other members from Framingham’s growing minority population to participate in the study. This more ethnically diverse study is called “The Omni Study,” and researchers are investigating to determine if minority populations have the same risk factors as those found in other cohort studies.

In addition, the NHLBI has begun a study of cardiovascular disease among African-Americans from the Jackson, MS, metropolitan area. Mississippi’s death rates from cardiovascular disease are among the highest in the nation, particularly among African-Americans. The primary objective of the study is to examine the causes of cardiovascular diseases in African-Americans in order to determine the best strategy to prevent these conditions.

To date, the Framingham study has been an overwhelming success. It has resulted in the publication of over 1,000 scientific papers and earned a respected reputation around the world. Its findings are considered so important that they are routinely taught as part of medical school education and have significantly changed the lifestyles of countless people around the world. The study has lead to the identification of the major risk factors of cardiovascular disease:

• High blood pressure
• High blood cholesterol
• Obesity
• Smoking
• Diabetes
• Reduced physical activity

In addition, the study has provided additional information on other related factors, such as age, gender, socioeconomic elements and psychological issues. A few additional milestones that resulted from Framingham research include:

• In 1960, Framingham researchers linked cigarette smoking to heart disease. In 1981, Framingham researchers debunked the idea that filter cigarettes provide any protection against heart disease among smokers.
  
  
• In 1976, Framingham researchers linked menopause to increased risk of heart disease.
  
  
• In 1978, psychosocial factors were found to affect heart disease.
  
  
• In 1994, an enlarged left ventricle was shown to increased risk of stroke. That same year, Framingham researchers linked lipoprotein (a) to heart disease.
  
  
• In 1996, researchers linked high blood pressure with high pressure by showing disease progression and gradual enlargement of the heart's chambers.

Further information about genetics is hoped to be obtained from the grandchildren and great-grandchildren of the original participants, as Framingham researchers have created a DNA library from more than 5,000 participants across two generations. Advances in diagnostic technology have helped provide even more detailed information with the new participants. As long as it continues to reveal valuable data, the study is expected to continue through future generations.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to the Framingham heart study:

1. How do you use the Framingham study with your patients?
   
   
2. How is the study related to the Coronary Risk Profile?
   
   
3. How can the Framingham Study help predict my risk for heart disease?
   
   
4. What lifestyle factors should I change based on this study?
   
   
5. How does family history contribute to my heart disease risk?
   
   
6. According to the study, how would you evaluate my diet and exercise habits?
   
   
7. Am I part of an ethnic group that was included in the study?
   
   
8. Which environmental factors were evaluated in the study?
   
   
9. Does the study have any implications for other medical conditions?
   
   
10. Can the study help predict my children’s risk of cardiovascular problems?