Obese Children Twice as Likely to Die Young?

By Kathleen Doheny

Reviewed by Louise Chang, MD

Feb. 10, 2010 -- Childhood obesity more than doubles the risk of dying before age 55, according to a new long-term study that followed nearly 5,000 children.

''The bottom line is, obesity in kids is a serious problem that needs to be taken seriously," study co-author William C. Knowler, MD, DrPH, tells WebMD. Although experts have known that for years, he says, the new research is definite confirmation.

"What this particular study shows is, obesity is going to cause excess premature death," says Knowler, chief of the Diabetes Epidemiology and Clinical Research Section of the National Institute of Diabetes and Digestive and Kidney Diseases.

Although recent data suggest a leveling off of obesity in the U.S., one in six teens is obese.

The study is in the New England Journal of Medicine.

Obesity in Childhood, Early Death Linked

Knowler and his colleagues evaluated 4,857 American Indian children who were born between 1945 and 1984, then followed them long-term. Most participants were at least half Pima or Tohono O'odham Indian. They lived in the area of the Gila River Indian Community in Arizona.

The researchers gathered data about the children's body mass index (BMI), glucose tolerance, blood pressure, and cholesterol levels. None of the children had diabetes at the beginning of the study, although 559 developed it during the study.

During a median follow-up period of nearly 24 years (half followed longer, half less), there were 166 deaths from natural causes before age 55. There were 393 deaths from external causes, such as accidents or homicide, before 55.

The researchers divided the participants into four groups, or quartiles, depending on their BMI. In all, 28.7% of the children were obese, according to their BMI.

Higher BMI, Higher Premature Death Risk

The researchers compared the risk of early death for those in the four BMI quartiles. "Those in the top quartile had over twice the rate of death from natural causes before age 55 as those in the lowest quartile of BMI," Knowler says.

Among these natural causes of death were alcoholic liver disease, cardiovascular disease, infections, cancer, diabetes, acute alcohol poisoning, and drug overdose.

''Obesity was not related to external causes of death, such as auto accidents," Knowler says.

Other Risk Factors and Premature Death

Knowler's team also evaluated whether glucose levels, cholesterol levels, or blood pressure during childhood boosted risk of premature death.

Death rates from natural causes among children in the highest group of glucose intolerance (a risk factor for developing diabetes) were 73% higher than among the children in the lowest group of glucose intolerance, the researchers found.

No substantial links were found between cholesterol levels and premature deaths. They did find that high blood pressure in childhood raised the risk of premature death from natural causes by about 1.5 times.

"Obesity was a stronger predictor of premature death than either abnormal glucose, cholesterol, or blood pressure," Knowler tells WebMD.