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

Eur Respir J. 2019 Feb 7;53(2):1801193. doi: 10.1183/13993003.01193-2018. Print 2019 Feb.

Abstract

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 (PM2.5) 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% versus 10.4%; p<0.001). Their average PM2.5 exposure was also higher (290.0 versus 72.0 µg·m-3; p<0.001). In addition to high PM2.5 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Air Pollutants / analysis
  • Air Pollution / analysis
  • Air Pollution, Indoor*
  • Altitude*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Kyrgyzstan
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Particulate Matter
  • Prevalence
  • Pulmonary Disease, Chronic Obstructive / epidemiology*
  • Pulmonary Disease, Chronic Obstructive / physiopathology*
  • Respiration
  • Risk Factors
  • Smoking
  • Spirometry*
  • Surveys and Questionnaires

Substances

  • Air Pollutants
  • Particulate Matter