Researchers aim to examine respiratory effects of body weight in preteens

Do overweight children have more breathing limitations, intolerance for exercise, and breathlessness when exercising than normal weight children, leading to possible misdiagnosis for conditions such as asthma?

Investigators with the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas, a joint program of UT Southwestern Medical Center and Texas Health Resources, received a 5-year, $2.7 million grant to find out and are seeking preteen volunteers.

"Excess fat on the chest can put an unfavorable burden on the respiratory system during exercise, but it's unclear whether that burden reduces their tolerance for exercise, makes breathing more difficult – a condition known as dyspnea on exertion, or contributes to other respiratory symptoms," said Dr. Tony G. Babb, Professor of Internal Medicine in the Division of Pulmonary and Critical Care Medicine at UT Southwestern, and Director of Cardiopulmonary Laboratory at the Institute for Exercise and Environmental Medicine.

"Such symptoms could lead to misdiagnosis for conditions such as asthma, placing overweight children at risk of unnecessary treatment and potentially a reluctance to exercise, explaining reports of low physical activity and fitness levels, which are counterproductive to weight loss," Dr. Babb said.

The Institute for Exercise and Environmental Medicine studies human physiology across the life span, especially physiology under extreme conditions and recently received a $2.7 million grant from the National Institutes of Health to study the problem.

To investigate, researchers plan to examine the respiratory effects of body weight in prepubescent boys and girls, including those with respiratory symptoms potentially misdiagnosed as asthma. They'll compare those children before and after one year, and look for the effects of continued weight gain as compared with prepubescent normal weight boys and girls.

"These results will have broad and immediate clinical impact on the care of overweight children, especially those with respiratory symptoms potentially misdiagnosed as asthma, and the results could alter interventional approaches for preventing and treating childhood obesity," said Dr. Babb, who holds the Effie and Wofford Cain Chair in Cardiopulmonary Research at Texas Health Presbyterian Hospital Dallas.

Participants can be boys or girls ages 8 through 12, must be able to ride an exercise bike, and have no heart disease, high blood pressure, diabetes or sleep apnea. They will receive pulmonary function tests and exercise tests, and have their body composition measured. Investigators are seeking 96 children to participate over the next five years and will need them to return one year later for retesting. To participate or for more information about the study, contact Rubria at 214-345-6574 or [email protected].

The study is being conducted in conjunction with the COACH (Center for Obesity and its Consequences in Health) Program at Children's Health, a multidisciplinary group of health care professionals dedicated to helping overweight children and families live healthy lifestyles. Co-investigators for the study with Dr. Babb are Dr. Tanya Martinez Fernandez, Associate Professor of Pediatrics, and Dr. Olga Gupta, Assistant Professor of Pediatrics and Internal Medicine, and a Dedman Family Scholar in Clinical Care.

Dr. Babb's laboratory focuses on studies of respiratory function during exercise, including dyspnea on exertion in overweight people.

"Perceived breathlessness is a common complaint of many overweight individuals. By testing pulmonary function, exercise capacity, respiratory mechanics, work of breathing, and body composition, we are able to identify connections between physiological markers, respiratory mechanics, and shortness of breath on exertion," said Dr. Babb, Principal Investigator for the Cardiopulmonary Laboratory. "Our overall goal is to find better approaches regarding the prevention, care, and treatment of exertional dyspnea in overweight children."

The Institute for Exercise and Environmental Medicine's Cardiopulmonary Laboratory is a state-of-the-art research/clinical laboratory used to study integrated physiological responses to exercise in humans. It includes a full-service exercise physiology laboratory, pulmonary function laboratory, and body composition laboratory – facilities that are used for NIH-funded research studies in pulmonary disease, normal aging, obesity, ventilatory control during exercise, and clinical cardiopulmonary exercise testing – and a nationally recognized referral center for the examination of patients with unexplained shortness of breath on exertion.