The presence of an altered nasal microbiome in patients with severe obstructive sleep apnea (OSA) is associated with inflammatory markers, according to the results of a discovery cohort from the World Trade Center (WTC)SNORE and a validation cohort from the Zaragoza Sleep cohort. Results were published in the American Journal of Respiratory and Critical Care Medicine.
The investigators sought to evaluate whether the composition of the nasal microbiota is linked to OSA and inflammatory biomarkers. In both cohorts, OSA was diagnosed with the use of home sleep tests. Nasal lavages were obtained from all participants in order to measure microbiome composition (based on 16S rRNA gene sequencing) and biomarkers of inflammation (eg, inflammatory cells, interleukin-6, and interleukin-8). Longitudinal 3-month samples were obtained from the validation cohort, which included post-continuous positive airway pressure (CPAP) treatment.
In both the discovery cohort (n=472) and the validation cohort (n=93), the severity of OSA was associated with differences in the diversity and composition of the microbiome. Furthermore, the nasal microbiomes of participants with severe OSA were found to be enriched with Streptococcus, Prevotella, and Veillonella. Differences in nasal microbiomes were associated with inflammatory biomarkers.
The use of network analysis identified clusters of co-occurring microbes that defined communities. A number of common oral commensals — Streptococcus, Rothia, Veillonella, and Fusobacterium — correlated with the apnea-hypopnea index. The composition of the nasal microbiota was not altered by 3 months of CPAP treatment.
The researchers concluded that additional experimental approaches to explore the causal associations between severe OSA and inflammatory markers are warranted. Longitudinal, interventional, and experimental investigations should be conducted to further study these relationships.
Wu BG, Sulaiman I, Wang J, et al. Severe obstructive sleep apnea is associated with alterations in the nasal microbiome and increase in inflammation [published online July 3, 2018]. Am J Respir Crit Care Med. doi:10.1164/rccm.201801-0119OC