In a recent pilot study, researchers tested the feasibility and effects of a 12-week home-based resistance training program. Their target patient population was children who have had a liver transplant and subsequently suffered with sarcopenia, a condition wherein there is loss of muscle mass and function. The researchers wanted to know whether the approach would be as successful for combatting sarcopenia in children as it has been in adults, according to earlier studies.
“Traditionally sarcopenia is associated with aging,” says Diana Mager, professor in the Faculty of Agricultural, Life & Environmental Sciences and adjunct professor in the Department of Pediatrics. But it has been shown to be increasingly prevalent among children who’ve had chronic, severe diseases and transplants.
The high prevalence of muscle loss after transplant is due to the medications patients must take. “They’re on immunosuppressive medications to keep their new organ working, and those medications can affect the quality and types of muscle fibres.” The condition can also be due to the malnutrition that many experience before transplantation.
Sarcopenia in these children is associated with several adverse outcomes including prolonged and repeated hospital stays, increased ICU stays, and high levels of fatigue that affect the kids’ quality of life. Mager and her team have shown that these issues can often persist for a decade or more after transplantation.
“On the outside, they’re growing just like other kids, their weight and height can be very similar, but their muscle quality is not the same as the muscle quality of a healthy child,” says Mager.
Mager worked with pediatrics professor Susan M. Gilmour and the Stollery Children’s Hospital pediatric liver transplant multidisciplinary health-care team for the pilot study. And, she collaborated with Norm Boule, professor in the Faculty of Kinesiology, Sport, and Recreation, to design a resistance training program that participants were able to complete at home with minimal equipment.
The transplant team serves patients from great distances, Mager says, making the home-based nature of the program an important factor. Not only do home-based programs typically have higher levels of adherence, according to Mager, they also offer rural patients who have limited access to rehabilitation facilities the opportunity to participate without undertaking costly travel.
“I think it’s really important to try to develop strategies where people can get the rehabilitation they need in their communities.”
At the start of the program, researchers showed study participants the proper technique for the exercises and familiarized them with the technology. They also measured their muscle mass, had participants do several muscle function tests such as pushups, gathered information from numerous questionnaires including the Pediatric Liver Transplant Quality of Life, and collected a three-day food record to assess dietary intake. The process was repeated at the final visit to track changes in the participants.
Over the 12 weeks of the study, participants completed resistance exercise sessions three times per week, reported their activity using an exercise journal workbook, and took part in weekly phone check-ins as well as monthly Zoom check-ins to review technique and ask questions.
About 75 per cent of participants successfully completed the program, and researchers measured increases in skeletal muscle mass as well as decreases in visceral fat content, indicating the accumulation of more lean body mass, which broadly speaking is a marker of improved health.
“We were happy to see that using a very low level of technology and an inexpensive intervention, we were able to get pretty good adherence and could show some favourable outcomes,” Mager says.
Resistance exercise may be particularly beneficial for patients with sarcopenia because of the type of muscle fibres the condition affects. In a recent study, Mager and collaborators found that patients with sarcopenia have reduced Type I muscle fibres, which are also called slow twitch fibres and are important for endurance exercises.
“Resistance exercise stretches the muscle, stimulates muscle anabolism (the process of building muscle) and appears to be very helpful for the deficits in the Type I skeletal muscle fibres that kids experience.”
Since immunosuppressive medication is the factor that often leads to this kind of muscle loss in children who’ve had a liver transplant, the research indicates they may find benefit in a resistance training program like the one tested for this study.
“This is a new area of research; sarcopenia in childhood has only been identified and documented since around 2018,” Mager says, but adds that since this muscle loss affects so many kids after transplant, it makes sense to identify and screen for it early, and prescribe the simple, at-home rehab strategies that the research demonstrates will improve it.