"Back pain and degenerative disk disease are yet another problem associated with obesity in children, along with type 2 diabetes," Dr. Judah G. Burns, a fellow in diagnostic neuroradiology, said. "Disk herniation and spinal disease are generally thought of as a problem of older people, but we're seeing it in obese youngsters, too. This is the first study to show an association between increased body mass index and disk abnormalities in children."

In this retrospective study, Dr. Burns and colleagues reviewed lumbar spine MRIs of 188 youngsters, ages 12 to 20, who were seen in their emergency department from 2005 to 2009. The MRIs were done for back pain only; trauma and other conditions that would predispose children to back pain were excluded from the review.

The researchers found that 97 (52%) of the patients complaining of back pain had some abnormality in the lumbar spine. All but six of these patients had disk disease; 55 had single level disease, and 36 had multi-level disease. The remaining causes of back pain were spondylolisthesis in 3 patients, Scheuermann's kyphosis in 1 patient, and isolated facet disease in 2 patients.

Height and weight data were available for 108 of the patients. Fifty-three had a body mass index (BMI) above the 75th percentile; 44 were above the 85th percentile, and 26 were above the 95th percentile.

According to the Centers for Disease Control, BMI greater than the 95th percentile is considered childhood obesity, and greater than the 85th percentile is considered at risk for obesity, Dr. Burns noted.

Using the 75th percentile as a cut-off point, of the 55 patients whose BMIs were below 75%, 34 (62%) had a normal MRI, and 21 (38%) had an abnormal MRI. Of the 53 patients whose BMI was greater than 75%, 18 (34%) had a normal MRI, and 35 (66%) had an abnormal MRI (p = 0.0043).

"We saw increased spine abnormalities with higher BMI. These results demonstrate a strong relationship between increased BMI in the pediatric population and the incidence of lumbar disk disease," he said.

They also demonstrate that disk disease affects young people, too, he said.

"Back pain in children is usually attributed to muscle spasm or sprain. A lot of the professional societies do not recommend doing an MRI in a child with back pain unless they have specific neurologic symptoms that would indicate a problem. The assumption is they probably don't have disk disease. Our experience in this series shows otherwise."

By Fran Lowry

Last Updated: 2009-12-01 16:58:19 -0400 (Reuters Health)

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