The 9th Soul

Study: Obese Children, Teens Have the Arteries of 45-Year-Olds

Posted in health, health defects by Fated Blue on November 18, 2008

Obese children have as much plaque in their neck arteries as middle-aged adults, according to a study presented this week at the American Heart Association meeting in New Orleans.

This precocious buildup of fatty deposits may give kids a looming risk of heart disease and other health problems that are beyond their years too.

“My premonition is that we will see more premature angina and strokes and such,” says study author Geetha Raghuveer, MD, an associate professor of pediatrics at the University of Missouri Kansas City School of Medicine.

In the study, Dr. Raghuveer and colleagues used ultrasound to measure the plaque in the carotid arteries of 70 obese children and teens with an average age of 13. (The study participants were 6 to 19 years of age.) The researchers measured the carotid artery intima-media thickness (CIMT) in the neck and found that the average CIMT was 0.45 millimeters, which is typical of adults in their mid-40s.

The researchers were not surprised that the children had narrowing of their arteries. “We have known that the carotid artery’s inner lining is thickened in children with some combination of the traditional risk factors: high cholesterol, obesity, hypertension, insulin resistance, diabetes, even exposure to tobacco smoking,” says Dr. Raghuveer.

But finding 30 years’ worth of extra fatty buildup exposes the seriousness of the problem, she says. Clogged arteries can increase the risk of stroke and heart attack.

“Saying that a child has the arteries of a 45-year-old brings it home, and so I think it’s a really nice way to catch people’s eye,” agrees Sarah De Ferranti, MD, director of the Preventative Cardiology Clinic at Children’s Hospital Boston.

She applauds the idea of counting children’s vascular age, or the state or their arteries, if it helps spur action against the ongoing epidemic of childhood obesity. “I think people are worried, but it’s worried-sitting-on-the-couch versus worried-getting-up-and-doing-something.”

Public health campaigns that try to get kids to exercise and eat healthier haven’t made much of a dent in the problem of childhood obesity, Dr. Raghuveer says; they also haven’t cut the rates of heart disease, diabetes, and other health problems that often go along with obesity.

“This study is another red flag to people out there who are managing these kids, and to parents especially,” says Dr. Raghuveer. “These kids not only have the risk factors—like high cholesterol and hypertension—but they also have damage to their arteries.”

That leaves parents and health-care professionals in charge of finding dietary and fitness solutions that work for individual children, she says. In some cases, it may even be necessary to use cholesterol-lowering statinsand blood pressure medications. All the children in the study had some kind of abnormality such as elevated total cholesterol, LDL or bad cholesterol, or triglycerides.

“Some of these children may need [drugs] either because they’re not compliant to dietary changes or because they don’t respond,” says Dr. Raghuveer.

There’s been some controversy lately about the wisdom of prescribing statins to young children. In July 2008, the American Academy of Pediatrics caused a firestorm when it revised its guidelines to say that statins were appropriate for use in some youngsters with high cholesterol. But most doctors agree that obese children with multiple risk factors might benefit.

Dr. Raghuveer’s hope is that CIMT might help doctors decide with greater precision which children might need extreme interventions, a scenario that interests Dr. De Ferranti as well.

“You can imagine in the future that someone would measure cholesterol and do one of these tests and decide, that is a child who might be right for statins,” says Dr. De Ferranti. “So we can treat the really high risk and focus on lifestyle issues for the rest of the children.”

Study May Demonstrate The Brain’s Role In Obesity

Posted in food, health, health defects, science by Fated Blue on October 17, 2008

Scientists, hoping to get a better understanding of how the brain influences obesity, used a brain scanner on people eating milkshakes and found that when the brain doesn’t sense enough gratification from food, people may overeat to compensate.

A blunted response in brain circuitry relating to pleasure could explain why obese people may get less satisfaction from food, U.S. researchers said on Thursday. They said some people may overeat to make up for the decreased pleasure, particularly if they carry a specific gene variant.

“The more blunted your response to the milkshake taste, the more likely you are to gain weight,” said Dr. Eric Stice, a senior scientist at the Oregon Research Institute who led the work.

Scientists have long known that genetics also play a major role in obesity – and one big culprit is thought to be dopamine, the brain chemical that’s key to sensing pleasure.

Dopamine, a chemical in the brain’s reward centers, is released into the body when people eat. The amount of pleasure from food depends on the amount of dopamine released.

The researchers recruited volunteers for the study; 43 female college students, ages 18 to 22 and 33 teenagers, ages 14 to 18. Body mass index calculations showed the young women spanned the range from very skinny to obese.

Brain scans were performed on the participants in order to view blood flow to the dorsal striatum, showing brain activity, as the girls and women drank a chocolate milkshake or a flavorless liquid.

The researchers said the scans showed obese people had less activity in the dorsal striatum, the part of the brain that releases dopamine in response to eating, when they drank a chocolate milkshake, compared to leaner people.

That brain region was far less active in overweight people than in lean people, and in those who carry that A1 gene variant, the researchers said. Moreover, women with that gene version were more likely to gain weight over the coming year.

“The evidence of blunted response leading to future weight gain clearly seems to suggest that people are over-eating in response to this diminished reward that they experience when they eat,” said Stice.

He likened it to the way people who smoke regular cigarettes. “If you give them the low-tar cigarettes, they make up for the lost tar by smoking more efficiently, and get more of it,” Stice said.

Stice concludes that the study really might show that these people with malfunctioning dopamine in fact eat because they’re impulsive.

“If doctors could determine who carries the at-risk gene, children especially could be steered toward recreational sports or other things that give them satisfaction and pleasure and dopamine that aren’t food,” said Stice.