The risk of developing coronary heart disease as an adult is more strongly related to childhood growth patterns than body weight at any particular point in development, according to a new study published in the Oct. 27 New England Journal of Medicine. Coronary heart disease is the leading cause of death in the United States.
"This study demonstrates for the first time that growth patterns before birth, after birth and into childhood reveal a risk of coronary heart disease later in life," said lead study author David Barker, M.D., Ph.D., professor of medicine (cardiology) at Oregon Health & Science University Heart Research Center.
In a retrospective study, Barker and his team found that Finnish children who had coronary heart disease as adults were born small, were thin at age 2 and then gained weight rapidly. They were also more likely to have insulin resistance later in life. Insulin resistance, a feature of type II diabetes, is a known risk factor for coronary heart disease.
"Small babies lack muscle, a condition that continues into childhood," said Barker, who is known internationally for his award-winning research program that examines the fetal origins of chronic disease in adults. "Rapid weight gain may lead to a high level of body fat in relation to muscle. This may explain why this growth pattern is related to insulin resistance and, thus, coronary heart disease."
Researchers found no relationship between increases in body mass index (BMI) and disease risk at age 2. However, by age 11, a strong pattern of increasing BMI indicated a 14 percent to 35 percent increase in risk of coronary heart disease as an adult. BMI measures weight in relation to height.
"Our latest advice is that children should enjoy plenty of physical activity and eat a nutritious diet to help prevent coronary heart disease in adulthood," said Kent Thornburg, Ph.D.,director of the OHSU Heart Research Center, professor of medicine (cardiology) in the OHSU School of Medicine and leading expert in the early origins of heart disease.
Researchers studied growth histories of 8,760 people born in Helsinki between 1934 and 1944. Childhood growth, including weight and height, was recorded once a month for the first two years and then annually through age 11. A total of 357 men and 87 women had been admitted to the hospital for coronary heart disease or had died from the disease. Researchers examined coronary risk factors in 2,003 of the study subjects.
People most at risk for coronary heart disease were those who weighed less than 3.0 kilograms (6.6 lbs.) at birth, whose BMIs were below 16 at age 2 and whose BMIs were above 17.5 at age 11. These people had three times the risk of heart disease compared with people whose BMIs fell from above 17 at age 2 to below 16 at age 11.
"These findings are further evidence that prevention of coronary heart disease depends on three things," Barker said. "First, mothers should have a balanced and varied diet before conception and during pregnancy. Second, infant growth after birth should be protected. Third, rapid weight gain after two years of age should be avoided in children who were small at birth or thin at 2 years."
Data for the study was collected in Finland, and some of the data analysis was done at the University of Southampton, where Barker also is a professor.
Barker and Thornburg are working together in partnership with the University of Southampton to develop the Oregon Woman's Study, a clinical research project that will study the nutritional needs of mothers and their babies. The first study site will open in rural Oregon in 2006.
"The Oregon Woman's study will present a wonderful opportunity to use what we have learned in this and other studies to uncover the relationship between nutrition at the outset of life and disease later in life," Barker said.
Coronary heart disease is caused by atherosclerosis, the narrowing of the coronary arteries due to fatty build-up of plaque. Coronary heart disease caused almost 500,000 deaths in 2002 - about 6 million worldwide. About 13 million people alive today have a history of heart attack, chest pain or both.
The OHSU Heart Research Center brings together more than 100 OHSU researchers from 30 different fields of medicine in an effort to further advances in heart health. Sharing research results and techniques has helped speed the progress of OHSU's research into the development of the heart and related diseases.
The forthcoming book by Barker, Foundation for a Lifetime, provides additional information about how to nourish mothers, babies and children, as well how to protect those born small against coronary heart disease later in life.