CHICAGO - The list of negative long-term consequences associated with anorexia nervosa may also include emphysema, according to findings presented here at the 2003 RSNA meeting.
“When compared to controls, women with anorexia were more likely to have hyperinflation of the lungs and poor gas exchange,” said principal investigator Harvey O. Coxson, Ph.D, an assistant professor of radiology at the University of British Columbia in Vancouver, British Columbia, Canada.
“In the anorectics, poor gas exchange was associated negatively with the body mass index,” said Coxson, who stressed that the parameters in the study were not the classic signs of emphysema, such as holes in the lungs.
“These findings may help physicians as they counsel people with anorexia and encourage them to resume normal nutrition,” said co-investigator Dr. John Mayo, co-director of the Thoracic Imaging Group at Vancouver General Hospital. “If a patient with anorexia is admitted with chest symptoms, it may be appropriate for the radiologist to suggest a chest CT.”
The investigators wanted to see if long-term protein-calorie malnutrition resulted in emphysematous changes in the lung parenchyma, because earlier animal studies had shown a connection between malnutrition and emphysema, as well as a reversal of the lung damage when nutrition was restored.
The investigators obtained CT scans from 18 women who had been diagnosed with anorexia nervosa according to the Diagnostic and Statistical Manual of Mental Disorders (DSM IV). The variables considered included sex, age, smoking history, body mass index (BMI), total body fat, hemoglobin, duration of anorexia, and duration of malnutrition, along with any history of respiratory disease. The investigators also recruited 16 women with normal nutrition who served as controls, as well as four smokers, two women and two men.
The investigators obtained CT scans from three regions of the lung: the aortic arch level, the carina, and the posterior position of the eighth rib. They used a multislice CT scanner (LightSpeed Ultra, GE Medical Systems, Waukesha, WI) and reconstructed the images by using 1.25, 2.5 and 5 mm CT slice thickness.
The investigators found no significant differences in age or pulmonary function between anorectics and control subjects. However, they found that only 30 percent of the women with anorexia had normal lung inflation, and that 40 percent of them had a mild hyperinflation and 30 percent had more marked hyperinflation. In contrast, 70 percent of the controls had normal inflation, with mild hyperinflation in 20 percent and more marked hyperinflation in 10 percent. Those rates were 40 percent, 50 percent, and 10 percent, respectively, among smokers. The anorectics were also more likely to have poor gas exchange, a finding that correlated positively with hyperinflation and negatively with BMI.
Coxson said he and his investigative team intend to follow the participants for two years to see if the restoration of nutrition will reverse the lung damage.
By Paula Moyer
AuntMinnie.com contributing writer
December 5, 2003
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