Do you know how old your kids' arteries are?
It's a potentially important question as scientists increasingly uncover links between healthy habits in childhood and risk for heart disease later in life. And there are growing concerns about the cardiovascular health of millions of children in the U.S. who are considered obese or overweight.
A new study suggests there is a simple way to assess a child's arterial health with a calculation based on an often-overlooked component of cholesterol: triglycerides.
The calculation is the ratio of triglycerides to HDL, or good cholesterol. It can be easily determined from a standard cholesterol blood test. In the study, based on nearly 900 children and young adults, researchers at Cincinnati Children's Hospital Medical Center found that the higher the ratio, the greater the likelihood a child would have stiff and damaged arteries.
"We are demonstrating vascular changes in supposedly healthy adolescents," said Elaine Urbina, head of preventive cardiology at Cincinnati Children's and lead author of the study. "Stiff vessels make your heart work harder. It isn't good for you." The study was published in the journal Pediatrics in April.
The problem is also called hardening of the arteries. In adults it typically arises from a combination of aging and the cumulative impact of blood pressure, cholesterol and other assaults on the walls of blood vessels over decades of life. It carries heightened risk for heart attacks, strokes and sudden death.
When it shows up in children, it's a sign of "accelerated aging," Dr. Urbina said, and likely raises the risk of dangerous outcomes relatively early in adult life. The good news is that doctors believe health can be restored to young people's arteries with regular physical activity and a healthy diet. This includes cutting back on sugary beverages and foods high in carbohydrates such as potatoes, white rice and pasta.
In late 2011, concern that a generation of children is growing up with already established heart risks prompted federal health officials with the support of the American Academy of Pediatrics to recommend universal cholesterol screening for kids, preferably between ages 9 and 11.
Generally, the focus of attention in such tests is LDL, or bad cholesterol, which at high levels has long been associated with increased chances of heart attacks and strokes. A large body of evidence shows that heart risk can be reduced by lowering LDL with one of a class of drugs called statins.
But high triglycerides and low HDL—the other components that are measured in a standard cholesterol blood test—are a hallmark reflection of the poor diets and sedentary lifestyles that researchers say are behind the wide prevalence of obesity among both children and adults. These markers may get less attention because efforts to develop drugs that prevent serious events by manipulating either component have come up short.
Triglycerides amount to an indicator of both fat and sugar in the blood stream. Dr. Urbina describes them to patients as having a backbone of fat with three (tri) sugars (glycerides) attached.
Other research has linked a high triglyceride-to-HDL ratio to arterial stiffness in adults. Dr. Urbina and her colleagues wondered whether a similar correlation existed in children and young people.
Participants in the study, who ranged in age from 10 to 26, underwent fasting tests for cholesterol, blood pressure, blood sugar and other heart-risk markers. They also had three different noninvasive tests that measure elasticity in blood vessels.
One third of the participants were found to have stiff arteries based on one of the elasticity tests; 13 percent had abnormalities on two of the tests and 3 percent had arterial stiffness according to all three tests.
The researchers found a "progressive rise" in both heart-related risk factors and stiff arteries as the triglyceride-to-HDL ratio increased.
The study wasn't large enough or intended to establish when a ratio is "healthy" or when especially aggressive treatment is called for. That will require additional research. But scientists found that the 378 participants whose ratio was in the highest of three groups had an average ratio of 2.7.
What this shows "is that being overweight and the cholesterol problems that often accompany it have an important impact on your blood vessels," said Sarah de Ferranti, director of preventive cardiology at Boston Children's Hospital, who wasn't involved with the study. A direct correlation to damaged blood vessels in kids hadn't previously been shown.