Those who opt for weight-loss surgery usually arrive at their decision with concerns about their health heavy on their minds.

In adult patients who undergo bariatric surgery, the benefits have been well-documented. High blood pressure, diabetes, sleep apnea and other problems can be improved with a successful, sustained weight loss following surgery.

In the pediatric population, patients, parents and doctors have banked on similar benefits, but until now the research on outcomes in teens has been relatively sparse.

New data is showing even more pronounced health benefits in young people than in adults, in particular a 95 percent reversal rate for diabetes. In adults, studies have shown diabetes disappears 50 percent to 70 percent of the time following surgery.

A new study from five hospitals, including Nationwide Children’s, shows that the surgery leads to an average weight decrease of more than 90 pounds, reversal of type 2 diabetes and high blood pressure in many patients, and improved kidney health.

The study included three years of data on 242 teens, mostly white girls, who weighed an average of 325 pounds. It appears in The New England Journal of Medicine and was discussed Friday at a medical conference on obesity in California.

In addition to the benefits, the researchers also point out some concerns, notably a spike in iron deficiency. Very few of the 13- to 19-year-olds had iron deficiency going into their operations. Three years later, 57 percent did.

The research team called for close monitoring of vitamin and mineral supplement use in kids who opt for surgery. Additional surgeries, most often gallbladder removal, were necessary in 13 percent of the patients.

In addition to the diabetes benefits, abnormal kidney function was reversed 86 percent of the time, hypertension disappeared in 74 percent of patients who had high blood pressure and abnormal lipid levels were corrected 66 percent of the time.

It’s important to note that the young patients undergoing weight-loss surgery were severely obese and faced multiple threats to their health, many of which already had started when they had their operations, said Dr. Marc Michalsky, surgical director of Nationwide Children’s Center for Health Weight and Nutrition.

In other words, it’s not something that happens because a teenager is carrying an extra 30 pounds and won’t commit to diet and exercise.

Previous studies have shown that about 2 percent of severely obese teens are successful shedding pounds and maintaining a healthy weight with lifestyle changes. An estimated 4.4 million children and teens in the United States are severely obese.

“I think with a lot of people, even in the medical community, it’s not yet widely understood that when you reach this level of obesity, the chance of achieving weight loss (without surgery) is low,” Michalsky said.

The kids who are having surgery are often in the 99th percentile on growth charts, or have a BMI of 40 or greater, he said.

Pediatric obesity surgery programs are beginning to seek accreditation through the American College of Surgeons and the American Society for Metabolic & Bariatric Surgery and follow guidelines for caring for young patients, including counseling before surgery and support afterward, Michalsky said.

Dr. Bruce Wolfe, professor of surgery at Oregon Health & Science University, said the new information about outcomes in young surgical patients is likely to encourage more pediatric hospitals to consider bariatric surgery in patients for whom other types of weight loss are unlikely. Wolfe, an expert in the field, did not work on the study.

“The diabetes response is particularly gratifying to see,” he said.

Megan Griffith, one of the patients included in the study, had the operation when she was 16 and weighed 310 pounds. She is now 22 and has maintained a weight of 185 pounds for years.

Though she didn’t have diabetes or heart disease prior to surgery, she looked to older family members with health troubles related to obesity and was concerned about what her future held, Griffith said.

When she was younger, Griffith had asthma attacks with too much exertion. Those are gone now. And she exercises regularly, something she struggled with at her heaviest.

“It’s a lot easier for me to be active now. I’m more healthy,” Griffith said. “I can run now. I never could run before.”

Surgery was difficult but worth it, said Griffith, who lives on the West Side. The first year after the operation was rough as her body recovered and she learned to manage her nutrition.

“I couldn’t eat and was in pain,” she said. “It’s a lot better now.”

The study, paid for by the National Institute of Diabetes and Digestive and Kidney Diseases, will continue in hopes of giving patients and physicians more long-term data to use when considering surgery.