People who are obese for a longer time -- when they start in their 20s, 30s and
40s -- are at an increased risk of developing hardened plaque in their arteries,
which increases their risk of a heart attack or a stroke later in life, a new
"With the obesity epidemic, people are becoming obese at a younger age than in
previous generations, and they are spending a longer period of their life with
obesity," says lead author Jared Reis, an epidemiologist in the National Heart,
Lung and Blood Institute's division of cardiovascular sciences.
"This is one of the first studies to show that a longer duration of obesity
independently contributes to hardened plaque in arteries," he says.
Cardiologist Mariell Jessup, president of the American Heart Association, says
the nation needs to focus on treating obesity in young people. "If we don't
tackle obesity in these young people, there will be an epidemic of coronary
artery disease just like there is currently an epidemic of obesity," she says.
About one-third of adults in the USA are obese, which is roughly 35 or more
pounds over a healthy weight. Experts have known that obesity increases the risk
of many diseases including type 2 diabetes, heart disease and some types of
Reis and colleagues analyzed data from about 3,300 white and African-American
adults who were followed for 25 years. Participants were ages 18 to 30 when they
began the study in the mid-1980s.
Information collected on the participants included their body mass index, a
number that takes into account height and weight, waist circumference, smoking
habits, diet, physical activity level, cholesterol, blood pressure and
development of type 2 diabetes. Participants also had scans at years 15, 20 and
25 to examine coronary artery calcification, also called hardened plaque.
Among the findings out Tuesday in JAMA, the Journal of the American Medical
--For every year the young adults were obese, their risk of developing hardened
plaque increased by 2% to 4%. This was independent of the participants' age,
sex, race, socio-economic status, BMI, waist circumference, smoking, physical
activity level, diet and alcohol consumption, Reis says.
--People who had the longest duration of obesity and abdominal obesity were at a
greater risk of developing high blood pressure and high cholesterol; had higher
rates of type 2 diabetes; and were more likely to use lipid-lowering medications
and high blood pressure medications.
Fat can play a role in development of atherosclerosis, Reis says. It occurs when
fatty substances, cholesterol, cellular waste, calcium and fibrin (a clotting
material) build up in the inner lining of an artery, according to the American
Heart Association. The buildup that results is called plaque.
Adds Jessup: "If there is inflammation in the lining of the coronary arteries,
the body attempts to heal that area and may subsequently develop plaque as a way
of healing. It's not healthy healing, but that's how it heals."
Justin Sullivan, Getty Images