As many as one in five American adolescents has LDL (bad) cholesterol levels that are too high and HDL (good) cholesterol levels that are too low -- a fact that many doctors say means that it may be time to start regular cholesterol screening as part of back-to-school check-ups.
According to a new report from the U.S. Centers for Disease Control and Prevention, American teens -- already identified as too often out-of-shape and overweight -- are also at risk for cholesterol problems once thought to be seen only in the middle-aged.
The CDC, which released the new cholesterol findings the Jan. 22 issue of Morbidity and Mortality Weekly Report, said high triglyceride levels are also a problem for adolescents.
The numbers come from a nationwide survey conducted from 1999 through 2006 known as the National Health and Nutrition Examination Survey (NHANES). This survey found that 20.3 percent of 12- to 19-year-olds had higher-than-normal levels of LDL cholesterol or triglycerides, or low levels of HDL cholesterol.
The findings are not shocking to doctors who treat teens, but as Dr. Joseph Zanga, a past president of the American Academy of Pediatrics said, "these numbers are more solid."
But solutions may be more difficult. "This problem is self-induced -- perhaps with some genetic predisposition -- and therefore can be self-corrected," said Zanga, who is chief of pediatrics at Medical College of Georgia in Columbus. "Americans must take major responsibility for their health. Diet, exercise [and] non-smoking lifestyle is what these children need."
Moreover, the numbers suggest bigger problems ahead for the American healthcare system, said Barbara Moore, president and CEO of Shape Up America.
"They suggest that 15 or 20 years down the road, when we expect these young people to be productive, hard-working adults contributing to society, they will instead be disabled, crippled by heart attacks, strokes and facing expensive treatments, surgery and rehabilitation. This is not a pretty picture."
Zanga noted that the American Academy of Pediatrics has been keeping an eye on obesity and cholesterol in kids for years, and the CDC said the new data suggest that about a third of American youths would be candidates for cholesterol screening on the basis of their body mass index (BMI) value, under guidelines already issued by the pediatricians.
The report was based on blood tests in 3,125 young NHANES participants. High LDL cholesterol was defined as at least 130 mg/dL. High triglyceride levels were 150 mg/dL or above. HDL cholesterol of 35 mg/dL or below was considered low.
Those 18 to 19 years old were much more likely to have these abnormalities than younger adolescents: some 28.8 percent of participants in this age group had at least one number in an unhealthy range, compared with 16.5 percent to 18.4 percent of those 17 and younger.
Prevalence of lipid abnormalities was also more common among white youths (22.4 percent) than among their black (14.6 percent) and Hispanic (18.6 percent) counterparts. Girls were somewhat less likely than boys to have one or more abnormalities.
Not surprisingly, overweight and obese youths were much more likely than those of normal weight to have unhealthy cholesterol and triglyceride levels. Some 43 percent of obese adolescents had at least one abnormality, as did 22 percent of those considered overweight for their age and height. By comparison, only 14.2 percent of normal-weight participants had abnormal levels.
An unsigned commentary by MMWR's editors noted that "untreated abnormal lipid levels in childhood and adolescence are linked to increased risk for cardiovascular disease in adulthood," but they stopped short of endorsing routine lipid testing for adolescents.
The AAP recommends screening youths with specific risk factors such as being overweight and family history of high cholesterol and triglyceride levels. The U.S. Preventive Services Task Force looked at the screening issue in 2007 and decided not to recommend for or against routine screening.
The MMWR editors suggested a strategy in line with the pediatrics group's recommendation. "Targeted screening of youths for abnormal lipid levels can identify those youths who might benefit from interventions that reduce the risk for [cardiovascular disease]," they wrote.
"Based on the findings in this study, clinicians should be aware of lipid screening guidelines and recommended interventions for children and youths who are overweight or obese," the editors added.
Such interventions include behavior and nutrition counseling and, if levels remain abnormal, drug treatment.
But the editors pointed out that fewer than 1 percent of NHANES participants included in the current study "had [cholesterol and/or triglyceride] levels high enough to warrant drug therapy according to AAP guidelines."