Native American ancestry, lung function, and COPD in Costa Ricans.

Area of Science:

• Genetics
• Pulmonology
• Epidemiology

Background:

• The association between Native American ancestry (NAA) and Chronic Obstructive Pulmonary Disease (COPD) or lung function in admixed Hispanic populations remains unclear.
• Understanding genetic contributions to respiratory health in diverse populations is crucial.

Purpose of the Study:

• To investigate the relationship between Native American ancestry (NAA) and the prevalence of COPD and lung function parameters in a Costa Rican population.
• To explore the potential mediating role of smoking behavior in this association.

Main Methods:

• A hybrid case-control/family-based cohort study of 578 Costa Ricans with and without COPD.
• Genome-wide genotyping to estimate individual ancestral proportions (European, Native American, African).
• Statistical analyses using regression models and mixed-effects models, adjusting for age, sex, education, and smoking behavior.

Main Results:

• Participants had an average of 35% Native American ancestry.
• Higher Native American ancestry was inversely associated with COPD and positively associated with FEV1, FVC, and FEV1/FVC.
• Approximately 31% of the effect of NAA on COPD was mediated by pack-years of smoking.

Conclusions:

• Native American ancestry is associated with reduced COPD risk and improved lung function (FEV1, FVC) in Costa Ricans.
• Smoking behavior partially mediates the association between Native American ancestry and COPD.
• Ancestral effects on lung function (FEV1, FVC) are independent of smoking behavior.