Associations of autophagy with lung diffusion capacity and oxygen saturation in severe COPD: effects of particulate air pollution

Abstract

Although traffic exposure has been associated with the development of COPD, the role of particulate matter <10 μm in aerodynamic diameter (PM₁₀) in the pathogenesis of COPD is not yet fully understood. We assessed the 1-year effect of exposure to PM₁₀ on the pathogenesis of COPD in a retrospective cohort study. We recruited 53 subjects with COPD stages III and IV and 15 healthy controls in a hospital in Taiwan. We estimated the 1-year annual mean levels of PM₁₀ at all residential addresses of the cohort participants. Changes in PM₁₀ for the 1-year averages in quintiles were related to diffusion capacity of the lung for carbon monoxide levels (r=−0.914, P=0.029), changes in the pulse oxygen saturation (ΔSaO₂; r=−0.973, P=0.005), receptor for advanced glycation end-products (r=−0.881, P=0.048), interleukin-6 (r=0.986, P=0.002), ubiquitin (r=0.940, P=0.017), and beclin 1 (r=0.923, P=0.025) in COPD. Next, we observed that ubiquitin was correlated with ΔSaO₂ (r=−0.374, P=0.019). Beclin 1 was associated with diffusion capacity of the lung for carbon monoxide (r=−0.362, P=0.028), ΔSaO₂ (r=−0.354, P=0.032), and receptor for advanced glycation end-products (r=−0.471, P=0.004). Autophagy may be an important regulator of the PM₁₀-related pathogenesis of COPD, which could cause deterioration in the lung diffusion capacity and oxygen saturation.

Keywords:

• 6-minute walk distance
• air pollution
• beclin 1
• lung function
• receptor for advanced glycation end-products

Acknowledgments

The authors wish to thank Miss Yi-Syuan Lin and Mrs Ching-Lin Li for technical assistance with this research. This study was funded by the Ministry of Science and Technology of Taiwan (MOST103-2314-B-038-018, MOST104-2621-M-038-002-MY3, and MOST102-2314-B-038-055-MY2), Taipei Medical University and Shuang Ho Hospital (103TMU-SHH-01-1 and 104TMU-SHH-05), and Shuang Ho Hospital (105-SHH-HCP-11).

Author contributions

All authors contributed toward data analysis, drafting and critically revising the paper and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.