RSNA 2016: The Impact of Obesity and ATV Injuries to the Chest in Pediatrics
Obesity may do additional irreparable harm to adolescents’ bones, according to a study presented at RSNA 2016. While obesity in pediatrics presents other health risks, such as cardiovascular disease and diabetes, researchers say it may also affect bone structure.
“While obesity was previously believed to be protective of bone health, recent studies have shown a higher incidence of forearm fractures in obese youths,” said the study’s lead author, Miriam A. Bredella, MD, radiologist at Massachusetts General Hospital and associate professor of radiology at Harvard Medical School in Boston.
Dr. Bredella and colleagues studied the relationship between adolescent obesity and bone structure. The researchers have recruited 23 obese adolescents with a mean age of 17 years and a mean body mass index (BMI) of 44 kg/m2 for the ongoing study.
The researchers performed 3D HR-pQCT—a type of computed tomography exam designed specifically for measuring bone mineral density and bone microarchitecture in the arms and legs—to determine the bone structure of the distal radius, an area of the forearm near the wrist. They also performed dual- energy x-ray absorptiometry (DXA) exams to determine body composition, including lean mass and visceral fat mass. Visceral fat is the deep fat in the abdomen that surrounds the internal organs.
Dr. Bredella adds, “Visceral fat secretes substances that promote chronic inflammation, and chronic inflammation stimulates formation of osteoclasts, which are the cells that resorb or break-down bone. In addition, vitamin D, which is important for bone health, is soluble in adipose tissue and gets trapped within fat cells.”
The study results showed that BMI was positively associated with cortical thickness and area; visceral fat mass was positively associated with cortical porosity; and lean mass was positively associated with trabecular density, volume and integrity.
The findings suggest that having a high amount of visceral fat coupled with a low amount of muscle mass puts adolescents at risk for weakened bone structure.
In another pediatric study presented at RSNA, researchers lead by Kelly N. Hagedorn, MD, radiology resident at McGovern Medical School at The University of Texas Health Science Center at Houston, found that 22% of adolescents suffered a chest injury after an ATV-related accident.
The report was based on a retrospective review of records from 1992 to 2013 for patients between 0 and 18 years old who underwent chest imaging at Memorial Hermann Red Duke Trauma Institute, a level 1 trauma center in Houston, after ATV-related incidents. During the study period, 455 patients were admitted. Of these, 102 (22%) had a chest injury.
The most common chest injury identified in the study was pulmonary contusion, or bruising of the lung, occurring in 61% of patients. In pulmonary contusion, blood and other fluids collect in the lung tissue, potentially leading to oxygen deficiency.
Other chest injuries included pneumothorax, or collapsed lung (45% of patients), and rib fractures (34% of patients).
Forty percent of patients with chest injuries required care in the ICU, compared to 22% of patients without chest injuries. Patients with chest injuries also had longer hospital stays. Eight children with chest injuries died.
“Our study further supports the need for increased public awareness of the risks—and potentially devastating consequences—of ATV use among children,” Dr. Hagedorn said.