Association Between Amerindian Ancestry and Chronic Obstructive Pulmonary Disease in the Chilean Mixed Population

Background/Objectives: Chronic Obstructive Pulmonary Disease (COPD) is one of the most common chronic non-communicable diseases in adults. The most critical risk factors are tobacco and air pollution. The familial aggregation of this disease and the fact that only 15-20% of smokers develop COPD demonstrate the existence of an individual susceptibility that would depend on genetic factors. The already-known susceptibility genomic variants explain only about 38% of the heritability of COPD. The present work analyzes the relationship between the percentage of Amerindian genomic ancestry of Chileans with morbidity and mortality of Chronic Obstructive Pulmonary Disease (COPD), adjusting for socioeconomic and environmental variables. Methods: We rely on the estimates of genomic ancestry percentages obtained in the Chilegenomico project in urban Chileans from 39 communes along eight regions of the country from north to south. From the public databases of the Departamento de Estadísticas e Información en Salud (DEIS) of the Chilean Ministry of Health, we obtained mortality rates and hospital discharge rates. We incorporated adjustment variables (communal data) obtained from other public databases. We performed correlation analyses and fitted negative binomial regression models to examine the association between Amerindian ancestries and COPD statistics. Results: A positive and significant association between Mapuche ancestry and hospital discharge and mortality rates for COPD was found in both simple and multiple analyses. In contrast, we found a negative and significant association between the percentage of Aymara genomic ancestry and COPD mortality rates. Conclusions: The levels of Mapuche and Aymara genomic ancestries have different and contrasting significant associations with COPD susceptibility and mortality in the Chilean mixed population.