After living with a spinal cord injury for 10 years, Mark Pascoe knows he needs to work hard to keep his weight down.
“I continue to gain weight and have to be careful with my diet. I was very active and strong before the injury and now it’s limited those abilities,” says Pascoe, 46, who broke his neck when he fell off a jet ski and hit a rock in the water.
Pascoe is not alone in his weight worries. As the nation fights a growing obesity epidemic, the problem is even more dramatic for people with spinal cord injury.
Researchers at the University of Michigan Health System are looking at how people with spinal cord injury burn calories and how that is affected by their muscle mass and body weight. The goal is to make better recommendations to people with spinal cord injury, but the research will also translate into greater understanding of obesity in the general population as well.
“Individuals with spinal cord injury have significantly less bone mass and muscle mass. As a result, their body weight is comprised of much more fat and less muscle or bone than you would see in an able-bodied individual,” says David Gater, M.D., Ph.D., director of Spinal Cord Injury Medicine at UMHS and director of the Spinal Cord Injury Research Center at the VA Ann Arbor Healthcare System.
Muscle burns calories even when the body is at rest. For someone with a spinal cord injury – who has less muscle mass – resting metabolism can be as low as half that of a person without a spinal cord injury. And that means even when people with spinal cord injury exercise, they burn significantly fewer calories.
Burning calories at a reduced rate, combined with limitations on physical activity, contribute not just to obesity, but to all the associated health problems: high cholesterol, coronary artery disease, diabetes and cancer.
“Cardiovascular disease has recently become the greatest risk for mortality for somebody with a spinal cord injury,” Gater says. “We realize that related issues – pre-diabetes, diabetes and high cholesterol levels – are contributing factors. All of those things essentially contribute to an accelerated aging process for the person with a spinal cord injury. Subsequently, their expected lifespan is going to be shorter and the quality of life may be reduced, depending upon how those secondary factors impact them.”
Gater’s team is looking at glucose tolerance, body composition and cardiovascular risk factors in people with spinal cord injury. A key question is how this group burns calories during different types of activities – from rolling their wheelchair to playing basketball. In his Spinal Cord Injury Exercise Lab at the VA, Gater has a device that measures oxygen consumption, which helps determine how many calories are burned. Another piece of equipment, called the “Bod Pod,” is used to measure a person’s body density and help determine how much fat and how much muscle is in the person’s body.