COPD is no more prevalent in Australian indigenous populations than non-indigenous, new research shows.

Using the Burden of Lung Disease protocol the study of 704 Indigenous and non-indigenous Australians from the Kimberly region of WA found the prevalence of COPD was 7.2% for Aboriginal Australians and 8.2% for non-indigenous participants.

The findings are in contrast to previous research that suggests the prevalence of COPD is higher for indigenous Australians, say the team of researchers from Queensland.

“Our hospital and mortality data had previously suggested that COPD was more prevalent in indigenous Australians,” lead author Nathania Cooksley from Cairns Hospital told the limbic.

“But this is the first study done in a large cohort not just measuring lung volume but in fact measuring the prevalence of COPD according to international criteria,” she said.

The study also confirmed previous findings that Aboriginal Australians had small lung volumes compared to non-indigenous Australians.

It was these smaller lung volumes that may reduce respiratory reserve and increase the chance that an intercurrent illness would be mislabeled as an exacerbation of COPD, Cooksley explained.

The research team’s hypothesis is the small lung volumes that they observed were due to socioeconomic and environmental risk factors more than genetic factors.

Although it requires further investigation it challenges some conventionally held assumptions, she said.

The clinical implications of their findings are two-fold, firstly there was a need to address socioeconomic and environmental risk factors such as overcrowding, poor nutrition and dust exposure.

“When we observe small lung volume or other abnormalities we also need to not just assume it is normal for a particular ethnicity,” she added.

“We believe it is time to consider low FVC, or what we term ‘small lung syndrome’ as a specific entity which may be a substantial driver of poorer respiratory outcomes for Aboriginal Australians and other comparable subpopulations both in high and low income countries,” the authors wrote in their paper published in Respirology.