THURSDAY, May 22 (HealthDay News) -- Children with sickle cell disease lose lung function faster and more significantly as they age, compared with other children of the same race and age, according to new research.

Contrary to previous research, the difficulty in breathing appears linked to a restrictive rather than obstructive or asthma-like pattern.

"The restrictive pattern of decline is supportive of early injury or inflammation resulting in progressive changes in lung volumes across age," lead researcher Dr. Joanna MacLean, of the department of respiratory medicine at Children's Hospital at Westmead in Australia, said in a prepared statement. "We expected that children with sickle cell disease would show greater loss of lung function than other children, but this had never been quantified, nor was the pattern of decline clear."

The research was presented May 18 at the American Thoracic Society's 2008 International Conference, in Toronto.

To determine the patterns of loss of lung function, the researchers analyzed 1,357 lung function results that were completed between January 1989 and January 2005 from 413 children with sickle cell disease (SCD) during routine sickle cell clinical visits. Lung volume measurements were also included for 1,129 records.

Analyzing lung function test results on the 413 children taken over 16 years, the researchers noticed a decline in the percent predicted values for all spirometry measures except FEV1/FVC ratio, a marker of airway obstruction. This pattern of decline confirmed a restrictive pattern with an average loss of 2 percent per year of total lung capacity.

"Our findings confirm that lung disease in SCD begins in childhood," MacLean said. "Using statistical modeling, we are able to predict the rate of decline of lung function. These results can be used as a baseline against which results from intervention studies can be compared."

She said the results emphasize the need for further investigation into the causes and treatment of lung disease in children with sickle cell disease.

More information

The Sickle Cell Disease Association of America Inc. has more about sickle cell disease.