As Americans face a growing epidemic of obesity, people with spinal cord injuries find themselves particularly vulnerable to the serious complications that come with carrying around extra pounds.
About 60 percent of the spinal cord injury patients seen by David Gater, M.D., Ph.D., director of spinal cord injury medicine at the University of Michigan Health System and the VA Ann Arbor Healthcare System, are obese – double the national rate of obesity among the general population. Paralysis caused by the injury leads to significantly less muscle mass, so these patients burn fewer calories, even at rest. In addition, they’re unable to exercise the largest muscles – the buttocks, thighs and hamstrings – limiting their ability to build muscle mass.
Gater’s research team has begun several new studies to look at how people with spinal cord injury burn calories, why their energy expenditure is different and how to deal with the disproportionate rate of obesity among these patients.
To showcase the accessible exercise equipment and tests designed to assess the fitness of people with spinal cord injury, Gater’s lab will host an open house from 11 a.m. to 3 p.m. Friday, Sept. 17 at the Ann Arbor VA Healthcare System.
“Many of my patients with spinal cord injury would be able to exercise and are highly motivated to exercise and take care of themselves, but they face significant barriers. Their physiology makes exercise more difficult, and physical access to gyms or equipment is an issue,” Gater says.
Gater’s lab includes a wheelchair ergometer that allows a person to propel a wheelchair over rollers, weight machines with wheelchair access, equipment to measure oxygen consumption which determines how many calories a person burns, an underwater weighing tank and a special capsule that more accurately measures body fat on a person with spinal cord injury.
“Standard measures of body composition don’t take into account the decreased muscle mass, bone mass and body water that people with spinal cord injuries have, so it’s difficult to assess accurately without special techniques,” Gater says.
In addition, people with spinal cord injuries do not burn calories as effectively as people without paralysis. Their heart rate is not as responsive to the increased exertion, blood pools in their legs reducing blood flow back to the heart, blood pressure is reduced, and the chest muscles don’t expand as efficiently, making breathing difficult.
Spinal cord injury specialists use wraps on the legs and abdominal binders to help increase exercise tolerance, and Gater’s work will help determine how many calories patients burn when performing various activities, from rolling their wheelchair to playing basketball.
Obesity increases a person’s risk of diabetes, heart disease and osteoarthritis, and this is true of people with spinal cord injuries as well. More than half of people who have lived at least 10 years with a spinal cord injury develop diabetes or pre-diabetes, and increased body weight significantly impairs their mobility and stresses their upper extremities. Exercise can help prevent or delay these effects.
“In a lot of ways, spinal cord injury represents an accelerated version of aging, as patients tend to develop these conditions at an earlier age than the general population,” Gater says.