High COPD prevalence at high altitude: does household air pollution play a role?

07 Feb 2019
Respiratory conditions
  • COPD
Respiratory topics
  • Risk factor: indoor air pollution
Type of resource
Peer-reviewed article
Brakema EA, Tabyshova A, Kasteleyn MJ, Molendijk E, van der Kleij RMJJ, van Boven JFM, Emilov B, Akmatalieva M, Mademilov M, Numans ME, Williams S, Sooronbaev T, Chavannes NH

Studies comparing chronic obstructive pulmonary disease (COPD) prevalence across altitudes report conflicting results. However, household air pollution (HAP), a major COPD risk factor, was mostly not accounted for in previous analyses and never objectively measured. We aimed to compare the prevalence of COPD and its risk factors between low-resource highlands and lowlands, with a particular focus on objectively measured HAP.We conducted a population-based, observational study in a highland (∼2050 m above sea level) and a lowland (∼750 m above sea level) setting in rural Kyrgyzstan. We performed spirometry in randomly selected households, measured indoor particulate matter with an aerodynamic diameter <2.5 µm (PM) and administered a questionnaire on other COPD risk factors. Descriptive statistics and multivariable logistic regressions were used for analyses.We included 392 participants: 199 highlanders and 193 lowlanders. COPD was more prevalent among highlanders (36.7% 10.4%; p<0.001). Their average PM exposure was also higher (290.0 72.0 µg·m; p<0.001). In addition to high PM exposure (OR 3.174, 95% CI 1.061-9.493), the altitude setting (OR 3.406, 95% CI 1.483-7.825), pack-years of smoking (OR 1.037, 95% CI 1.005-1.070) and age (OR 1.058, 95% CI 1.037-1.079) also contributed to a higher COPD prevalence among highlanders.COPD prevalence and HAP were highest in the highlands, and were independently associated. Preventive interventions seem warranted in these low-resource, highland settings. With this study being one of the first spirometry-based prevalence studies in Central Asia, generalisability needs to be assessed.