Too much body fat leads to stiffening of arteries in teens

October 2005 –

Excess body fat and its metabolic consequences can cause stiffening of the arteries in teenagers, according to a recent study. The study found that the risk of stiffening of the arteries increased with the amount of extra body fat. This relationship was seen at body mass indexes well below that which would be considered "obese." The results, published in the September issue of Circulation, emphasize the importance of controlling excess body fat in children and teens.

Stiffening of the arteries related to atherosclerosis begins in childhood and can lead to cardiovascular problems later in life. The “classic” adult risk factors for atherosclerosis of the arteries – high blood pressure, high cholesterol, and smoking – do not usually arise in childhood. However, an increasing number of children are becoming overweight and obese. In the developed world, obesity is reaching epidemic proportions, especially in children and teens. This study set out to determine the importance of excess body fat, its metabolic consequences, and the classic risk factors in the development of artery disease in children and teens.

In this study, 471 teens (249 boys and 222 girls), aged 13 to 15 years, were measured for body weight, percentage body fat, waist circumference, stage of puberty, blood pressure, total cholesterol, LDL "bad" cholesterol, HDL "good" cholesterol, triglycerides, and pulse pressure of the brachial artery in the arm. The study also measured the mean change in diameter of the brachial artery between the time the heart is at rest and the time it contracts. This last measure is called the brachial artery distensibility. Reduced artery distensibility is a clear marker for stiffening of the arteries, and leads to cardiovascular problems in adulthood.

One hundred eighty-eight of the participants in this study had previously had their cardiovascular risk factors and brachial artery distensibility measured in a study four years earlier, when they were nine to 11 years of age. Of these, 152 had given a blood sample to test for total and HDL cholesterol at that time.

In the present study, teens with excess body fat were found to have reduced artery distensibility. More excess body fat was associated with a greater reduction in artery distensibility. This means that teens who had higher amounts of extra fat were more prone to developing stiffening of the arteries. The relationship of excess body fat to reduced artery distensibility was not present four years earlier in the children who were tested at nine to 11 years of age.

Increased levels of total cholesterol, LDL cholesterol, and diastolic blood pressure, the pressure when the heart is in between contractions, also led to reduced artery distensibility, both in the present study of teens aged 13 to 15, and in the study four years earlier on children aged nine to 11.

The other classic risk factors, such as systolic blood pressure, the pressure when the heart is contracting, triglycerides, and HDL cholesterol, did not have a statistically significant relationship with arterial distensibility.

The study concluded that excess body fat and its metabolic consequences are associated with problems in the walls of the arteries by the teenage years. The more extra body fat a teen has, the more likely there will be stiffening of the arteries.

"Given the epidemic of overweight in children, and the strong association between childhood and adult obesity, it is fair to assume that unless something drastic happens, we will soon be faced with an epidemic of heart disease in younger adults. Parents may outlive their children. This study provides evidence that this process is well underway," says Dr. Brian McCrindle, staff cardiologist and section head, epidemiology at The Hospital for Sick Children.

These observations emphasize the importance of reducing excess body fat in childhood, by combining dietary changes and exercise. For information on eating right during the teenage years, see .