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

• Published in: The European respiratory journal Vol. 53; no. 2; p. 1801193
• Main Authors: Brakema, Evelyn A, Tabyshova, Aizhamal, Kasteleyn, Marise J, Molendijk, Eveline, van der Kleij, Rianne M J J, van Boven, Job F M, Emilov, Berik, Akmatalieva, Meerim, Mademilov, Maamed, Numans, Mattijs E, Williams, Sian, Sooronbaev, Talant, Chavannes, Niels H
• Format: Journal Article
• Language: English
• Published: England European Respiratory Society 01.02.2019
• Subjects: Original
• ISSN: 0903-1936; 1399-3003; 1399-3003
• DOI: 10.1183/13993003.01193-2018

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.