Weight Loss Surgery Leads to Weaker Bones in Kids, New Study Finds
More bone marrow fat, less dense bones.
Bariatric surgery, which involves reshaping the stomach so as to restrict food consumption and curb appetite, is increasingly being considered for children as rates of childhood obesity continue to climb. But new research published Tuesday in the journal Radiology suggests that using bariatric surgery to lose weight in your youth may come with a major tradeoff: weaker bones.
Led by Miriam Bredella, professor of radiology at Harvard Medical School, the researchers followed a group of 54 adolescents and young adults, all either moderately or severely obese, between ages 13 and 24, from 2015 to 2020. Half of the participants underwent a sleeve gastrectomy — where about 75 percent of the stomach is permanently removed, leaving behind a smaller, banana-shaped sleeve — and the other half had no surgery at all, just dietary and exercise counseling.
CT analysis of the lower spine of an 18-year-old woman with severe obesity. The left is before and the right is 24 months after sleeve gastrectomy. Black and white areas show the distribution of bone mineral density and colored areas are bone failure. Red indicates weaker bone. Shades of gray indicate different bone densities, with white being dense bone and black being little or no bone mineral.
Two years before and after starting the weight loss treatments, the scientists gathered data on both groups’ bone health through physical exams, blood tests, and CT scans. They created computer models to simulate bone strength and see where breakage would happen if a force were applied.
While the kids in the surgery group saw a dip in their body mass index (or BMI) compared to the non-surgery group, they also had a lot of fat circulating in their bone marrow, something that past research suggests is directly linked with bone loss. CT scans of their spines also found that this group had decreased bone density and strength.
“We found that bone strength was lower two years after weight-loss surgery, while bone marrow fat, a marker of bone weakening, was increased, suggesting that weight-loss surgery has negative effects on bone health,” Bredella said in a press release.
The fact that bariatric surgeries like sleeve gastrectomies can lead to bone loss and fracture isn’t new. But these findings are concerning for kids whose bones are still growing. An updated guideline by the American Academy of Pediatrics includes weight loss surgery and drugs like Wegovy in treating obesity in children ages 12 and up. The study stresses that if an adolescent or young adult does go through with the procedure, their bone health needs to be continuously monitored and mitigated with dietary supplements like vitamin D and calcium or other therapies during their weight loss journey.
“As bariatric surgery is increasingly performed in adolescents, its effect on bone health needs to be emphasized, especially to the physicians who will continue to provide routine medical care for these patients,” said Bredella. “We hope that our study will raise awareness on the effects of weight-loss surgery on bones in adolescents with obesity.”
