New findings highlight obesity as a risk factor for back problems in adolescents

Spinal MRIs were abnormal in 68% of patients studied whose BMI was in the 75th percentile.

A retrospective study of spinal MRIs performed on 188 adolescents presenting with back pain identified a lumbar spine abnormality in 52.1% of them, most of which occurred in the discs of overweight children.

“This is the first study to show an association between increased body mass index (BMI) and disc abnormalities in children,” Judah G. Burns, MD, a diagnostic neuroradiology fellow at The Children’s Hospital at Montefiore in New York, said in a Radiological Society of North America (RSNA) press release.

Burns presented the findings at the RNSA 2009 annual meeting.

Low back complaints

To test the hypothesis that overweight adolescents have a higher incidence of disc abnormalities than their normal-weight peers, Burns and colleagues studied patients aged 12 to 20 years old with back pain who were imaged at their hospital in a 4-year period.

They excluded trauma cases and those predisposed to back pain.

Researchers determined an age-adjusted body mass index (BMI) for 106 of the 188 patients. Of that group, 54 patients had a BMI in the 75th percentile for their age and in 35 of them (68.5%) the spinal MRI was abnormal.

BMI and disc disease

By comparison, 18 children (34.6%) with either normal or below normal BMI had an abnormal spine MRI. Burns told Orthopedics Today there was about a 20% rate of abnormal MRIs in a pseudo control group he studied.

“We observed a trend toward increased spine abnormality with higher BMI,” Burns stated, noting in the release his study’s data may signal a significant public health problem given the health costs of back pain in the United States and the significant morbidity of back pain in adulthood.

He told Orthopedics Today, “It highlights the fact that there is a consequence of end organ damage from childhood obesity.”

Burns stated in the release, “In children, back pain is usually attributed to muscle spasm or sprain. It is assumed that disc disease does not occur in children, but my experience says otherwise.” – by Susan M. Rapp

Reference:

• Burns JG, Erdfarb A, Schneider J, et al. Pediatric lumbar disc disease: MRI abnormalities in normal and overweight children. Presented at RSNA 2009 95th Scientific Assembly and Annual Meeting. Nov. 29-Dec. 4, 2009. Chicago.
• Judah G. Burns, MD, can be reached at Montefiore Medical Center, 111 E. 210th St., Bronx, NY 10467; 718-920-7223; e-mail: judahburns@gmail.com.

This is a timely and interesting if not intriguing study, especially when 20% of their pseudo control group and 34.6% of their normal and below-normal BMI patients had abnormal MRI findings. A recurring problem I now face is the increasing number of adolescents with normal BMIs referred from their pediatricians with an MRI report of “bulging” disc disease who are currently asymptomatic … And the affected disc is not in the previously symptomatic region.

Intuitively one assumes that if you have a large body, there is a greater load on the disc which could become problematic. The issue of MRI sensitivity and specificity to identify clinical and image correlation is a challenge.

Since I mainly treat pediatric spine deformities and the majority of my back pain patients are active adolescents, cheerleaders, gymnasts, dancers, etc., with normal BMI who sustain a back injury from activities or sports, I cannot comment further, but obesity being a possible precursor to disc abnormalities is an interesting concept and definitely deserves further study.

– Alvin H. Crawford, MD
Orthopedics Today Editorial Board