Dr. Harrell reported on findings from 2,034 children (1,020 female, 1,014 male) ages 8 to 17. In the study, 48.1% of the children were Caucasian, 42.9% were of African descent and 9.1% had other racial backgrounds.
Body mass index (BMI), blood pressure, lipids and glucose tolerance were all measured in each child. It was found that among 8 and 9 year olds (n=384) 8.6% had three or more risk factors. Among 14 to 17 year olds (n=468), 11.3% had at least three risk factors. The highest rates of multiple risk factors were found in children who were aged 10 to 13 (n=1,182) at 17.1%.
The most frequently found risk factor was decreased HDL cholesterol, which occurred in 41.9% of the children. Levels were considered low if they fell below 40 mg/dL in boys or 50 mg/dL in girls. High triglyceride levels were found in 8.6% of the children. A significant portion, more than 25%, of the children were overweight and had a BMI that was higher than it should be for children of similar weight, height and sex. In the US, obesity is considered an epidemic. According to the American Obesity Association, the rates of obesity in children have more than doubled since the 1970s.
OBESITY KEY RISK FACTOR
Obesity alone can trigger further risk factors. For one, it is linked to the development of insulin resistance. "Insulin is needed to allow glucose to be used by the cells, and is required by the body. But as cells become resistant to the action of insulin, the body compensates by producing more insulin, which makes sense, so you have glucose homeostasis," Dr. Harrell said.
Unfortunately, insulin resistance, in turn, is linked to the development of specific types of dyslipidemias (unhealthy levels of triglycerides, cholesterol and other lipids). Triglycerides go up and HDL cholesterol ("good" cholesterol) levels drop. In addition, high blood pressure can develop.
Over time, high insulin resistance can lead to the development of Type-2 diabetes, something which was once called adult-onset diabetes. In the population in general "researchers are finding about a third of diabetics aged 12 to19 have Type-2 diabetes instead of Type-1," Dr. Harrell said.
In the CHIC study population, about 5% of the children had glucose intolerance. Typically, people have metabolic syndrome for a number of years before glucose tolerance becomes impaired.
Dr. Harrell's key message is to get children to be physically active on a regular basis, and to help them improve their eating habits and to fight obesity.