Children who get little physical activity are at greater risk for developing symptoms that are pre-cursors to heart disease by their teenage years, a new study says.
The study, from the University of North Carolina at Chapel Hill, found that children who got low levels of physical activity were more likely to test positive for metabolic syndrome (MS).
The syndrome encompasses a variety of symptoms that indicate a high risk for developing heart disease, including hypertension, low levels of HDL (the so-called "good" cholesterol) and obesity.
Almost 400 kids between the ages of seven and 10 were questioned about their levels of physical activity and tested for aerobic fitness, body mass index and blood pressure. They were then re-tested seven years later as adolescents.
More than 4 per cent of the adolescents tested positive for three or more symptoms of MS. This group was six times more likely to have low aerobic fitness levels and more than five times more likely to have low physical activity levels.
A child who didn't get any vigorous exercise, such as playing soccer or basketball, and got less than 20 minutes a day of moderate exercise, such as brisk walking, was considered to have a low physical activity level.
"Children today live a very sedentary life and are prone to obesity," lead study author Robert McMurray, a professor of exercise and sports science at UNC, said in a statement.
"This is the first study to examine the importance of childhood fitness levels on your metabolism as a teenager. It's obvious now that there is a link and this is something which we need to pay attention to by encouraging our kids to keep fit, or suffer the consequences later in life."
The study was published Friday in the journal Dynamic Medicine.
Abstract
Adolescents with metabolic syndrome have a history of low aerobic fitness and physical activity levels by Robert G. McMurray, Shrikant I. Bangdiwala, Joanne S. Harrell, and Leila D. Amorim
Purpose: Metabolic syndrome (MS) is a clustering of cardiovascular disease risk factors that identifies individuals with the highest risk for heart disease. Two factors that may influence the MS are physical activity and aerobic fitness. This study determined if adolescent with the MS had low levels of aerobic fitness and physical activity as children.
Methods: This longitudinal, exploratory study had 389 participants: 51% girls, 84% Caucasian, 12% African American, 1% Hispanic, and 3% other races, from the State of North Carolina. Habitual physical activity (PA survey), aerobic fitness (VO2max), body mass index (BMI), blood pressure, and lipids obtained at 7-10 y of age were compared to their results obtained 7 y later at ages 14 -17 y.
Results: Eighteen adolescents (4.6%) developed 3 or more characteristics of the MS.
Logistic regression, adjusting for BMI percentile, blood pressure, and cholesterol levels, found that adolescents with the MS were 6.08 (95%CI = 1.18-60.08) times more likely to have low aerobic fitness as children and 5.16 (95%CI = 1.06-49.66) times more likely to have low PA levels.
Conclusions: Low levels of childhood physical activity and aerobic fitness are associated with the presence of the metabolic syndrome in adolescents. Thus, efforts need to begin early in childhood to increase exercise.
