Framingham Heart Study

Framingham Heart Study

FRAMINGHAM HEART STUDY

Almost daily, we are warned that certain
behaviors, certain lifestyle choices, may be dangerous to our cardiovascular
health. Many of these assertions are based on sound medical logic and years
of careful observation. How do we know what we know? The following was provided
by the National Heart, Lung, and Blood Institute (NHLBI), part of the U.S. National
Institutes of Health.

Fifty years have passed since medical researchers

began tracking the course of cardiovascular disease in a small New England town. Much of

what is known today about risk factors for cardiovascular disease: cigarette smoking, high

blood pressure, high blood cholesterol, overweight, physical inactivity, and

diabetes—was a mystery before this project, the "Framingham Heart Study."

In 1948, more than 5,000 residents of Framingham,

MA, agreed to participate in a long-term ongoing study of heart disease, to be

administered by the newly established National Heart Institute (today the NHLBI) of the

National Institutes of Health.

At the time the study was conceived, it was

already known that cardiovascular disease was the leading cause of death and serious

illness in the United States. But researchers wanted to track a large population, to see

how heart disease develops. The original participants, who were between 30 and 60 years of

age at the time they enrolled in the study, underwent detailed physical examinations every

two years, including an electrocardiogram, chest X ray, and laboratory tests.

The Framingham Heart Study is now considered one

of the longest, most important epidemiological studies in medical history. In the 1960s,

the study demonstrated the role cigarette smoking plays in the development of heart

disease. Those findings helped to fuel the first anti-smoking campaigns of that era.

Data gathered from the participants also showed

how elevated blood pressure contributes to the risk of heart attack and stroke. In 1972,

the NHLBI established the National High Blood Pressure Education Program. Over the last 25

years, the program's efforts have helped to increase public awareness about the risks of

high blood pressure, promote better control of blood pressure, and reduce deaths from

strokes.

The Framingham study provided researchers with

knowledge of how dietary fat can increase the risk of heart disease. It showed a link

between cholesterol levels in the blood and an individual's risk for developing heart

disease. Later, Framingham data also demonstrated the beneficial role of high-density

lipoprotein (HDL) cholesterol and the negative consequences of low-density lipoprotein

(LDL) cholesterol. The National Cholesterol Education Program was established in 1985 by

the NHLBI after studies, including Framingham, proved that a lower blood cholesterol level

meant a lower risk of heart disease. This program has helped to educate physicians,

patients, and the public about the dangers of high blood cholesterol and to bring about

reductions in Americans' blood cholesterol levels.

Today, about 75 percent of the original

Framingham participants have died. The most common cause of death was cardiovascular

disease. But in 1971, the study began a second phase by enrolling more than 5,000 children

of the original participants along with their spouses. This second generation is providing

researchers with valuable information about the genetic patterns of heart disease.

Framingham will continue to evolve as new

technologies emerge to monitor the heart and the progression of cardiovascular disease. To

stay on the cutting edge of medical science, the study has implemented new technologies

over the years as they became available.

The study also is collaborating with researchers

around the world to gather information about other topics, including osteoporosis,

nutrition, and eye and lung diseases.

Several new Framingham initiatives are under way,

including research into the genes responsible for heart disease, high blood pressure, lung

disease, and osteoporosis. Enrollment of minority participants is helping the researchers

gather important data on risk factors in minority populations.

The commitment of the residents of Framingham,

MA, has been crucial in the study's efforts. Their help has contributed to many of the

major findings about heart disease made in the last half-century. Their continued

participation is a crucial element for future success in the battle against the nation's

number-one killer—cardiovascular disease.

BLOOD CHOLESTEROL LEVELS

Desirable Borderline High

High

Total < 200mg/dL 200-239mg/dL 240mg/dL &

up

Cholesterol

LDL < 130mg/dL 130-159mg/dL 160mg/dL & up

Cholesterol

HDL a low HDL cholesterol is less than 35mg/dL

Cholesterol

BLOOD PRESSURE LEVELS

Systolic Diastolic

Optimal <120 mm Hg and <80 mm Hg

Normal <130 mm Hg and <85 mm Hg

High-Normal 130-139 mm Hg or <85-89 mm Hg

High

Stage 1 140-159 mm Hg or 90-99 mm Hg

Stage 2 160-179 mm Hg or 100-109 mm Hg

Stage 3 >=3D 180 mm Hg or >=3D 110 mm Hg