The proportion of U.S. adolescents with diabetes or borderline diabetes has jumped dramatically since the late 1990s, raising the possibility that this generation of young people will face high rates of heart disease and other complications as adults.
Twenty-three percent of adolescents between the ages of 12 and 19 had diabetes or the precursor condition known as pre-diabetes, as of 2008, up from just 9% in 1999, according to a new analysis of national survey data from the Centers for Disease Control and Prevention. By contrast, the rate of obesity — a leading cause of type 2 diabetes in this age group — was largely flat over the same time period, as previous CDC reports have shown. Thirty-four percent of adolescents were overweight or obese in 2008, compared to 33% in 1999. Likewise, rates of other risk factors for heart disease, such as high blood pressure (14%) and high LDL cholesterol (22%), also known as bad cholesterol, remained high but largely unchanged from the previous decade.
The percentage of U.S. teenagers with “pre-diabetes” or full-blown type 2 diabetes has more than doubled in recent years — though obesity and other heart risk factors have held steady, government researchers reported.
The good news, the researchers say, is that teen obesity rates leveled off between 1999 and 2008 — hovering between 18 percent and 20 percent over the years. Rates of high blood pressure and high LDL cholesterol (the “bad” kind) also remained steady.
But the picture was different with so-called pre-diabetes and with type 2 diabetes. Those conditions were seen in nine percent of teens in 1999-2000, but that figure rose to 23 percent in 2007-2008, the researchers report in the journal Pediatrics.
Lead researcher Ashleigh May, of the Centers for Disease Control and Prevention (CDC) stated that, “It was unexpected, especially since obesity has been leveling off.”
This study did not separate pre-diabetes from type 2 diabetes, so it’s not clear how much of the rise was in full-blown diabetes, May said. But in the past the CDC has estimated that between 2002 and 2005, the yearly rate of new type 2 diabetes diagnoses was 8.5 for every 100,000 kids ages 10 to 19.
At one time, type 2 diabetes was almost unheard of in children. But with the rise in childhood obesity in recent decades, more kids have been diagnosed with that form of diabetes, or its potential precursor pre-diabetes. Unhealthy blood sugar levels — or blood pressure or cholesterol levels — may not affect a teenager right away. But the concern, May noted, is that those things tend to “track” into adulthood, when they may contribute to heart attacks or stroke.
The Pediatrics report also found that overall, half of overweight teens and almost two-thirds of obese adolescents have one or more risk factors for heart disease, such as diabetes, high blood pressure or high levels of bad cholesterol. By comparison, about one-third of normal-weight adolescents have at least one risk factor. When these risk factors are present in young people, the problems may persist into adulthood, May says.
“It’s promising that we didn’t see a rise in obesity or hypertension or (high LDL),” May said. “But we still have a lot of work to do.” The results are based on a national sample of almost 3,400 teenagers who had physical exams and blood tests between 1999 and 2008. Rates of obesity remained stable over the years, landing at 20 percent by 2008. Another 15 percent of kids were overweight.
By 2008, 10 percent of teens had “pre-hypertension” — which means their blood pressure numbers were higher-than-normal, but not high enough to meet the definition of hypertension. Another three percent had full-blown high blood pressure.
When it came to LDL cholesterol, six percent of teens had high levels and 13 percent were borderline-high in 2008. Those figures were similar to the ones almost a decade earlier. Pre-diabetes/diabetes was the exception.
There are limitations to the study, May’s team acknowledges. One is that they gauged pre-diabetes and diabetes from a single blood sugar measurement — which may be less reliable in kids than in adults. Still, May said the “big message” here is that children and teenagers need more help with following a healthy diet and staying physically active.
The U.S. Preventive Services Task Force, a government-backed panel, recommends that children age six and older be screened for obesity. If a child is heavy, pediatricians should offer families behavioral counseling, or refer them to someone who can. The American Academy of Pediatrics (AAP) recommends that children have their blood pressure checked regularly starting around age four. The AAP also suggests that kids’ cholesterol be checked between the ages of nine and 11, and then again between the ages of 17 and 21.
Pediatrics, online May 21, 2012.