Developmental Adaptation Hypothesis: Aerobic capacity, Submaximal Arterial Saturation and Pulmonary Volumes in Peruvian Quechua Natives

The Quechua populations have inhabited the Andes for hundreds of generations. The ability to thrive in this hostile environment, leading an active and healthy life has generated research questions about the special phenotype of Andean highlanders compared to their sea-level counterparts, such as their higher pulmonary volumes and their outstanding work capacity in spite of the challenge of oxygen transport and delivery in hypoxia. In high altitude natives, there have been two main explanations for the origins of the aforementioned traits: genetic adaptation through natural selection and developmental adaptation through the exposure to hypoxia during growth.;The present study used a partial migration study design to address questions of genetic/developmental contributions on lung volumes in females using a panel of 70 ancestry informative markers (AIMS) to determine the individual percentage of Native American ancestry; and the effects of developmental exposure to hypoxia on the aerobic capacity and submaximal arterial oxygen saturation in male and female Peruvians. The study on lung volumes compared forced vital capacities, residual volumes and total lung capacities in (a) sea-level born and raised females (BSL, n=34) from Lima, Peru (150m), and (b) High-altitude born and raised females (BHA, n=31) from Cerro de Pasco, Peru (4,338m), whereas the study on aerobic capacity and submaximal arterial saturation compared males and females (a) born at sea-level (BSL), with no developmental exposure to hypoxia (N=34) and (b) born at high-altitude (BHA) with full developmental exposure to hypoxia (N=32), but who migrated to sea-level as adults.;The main results of the study were: 1) BHA females had larger lung volumes compared to BSL; 2) BHA had significantly higher aerobic capacity at hypoxia compared to BSL, adjusting for sex; and 3) BHA maintained higher arterial oxygen saturation levels during submaximal exercise at hypoxia compared to BSL. In sum, results suggested that developmental exposure to high altitude constitutes an important factor to determine larger pulmonary volumes, superior exercise performance and higher submaximal arterial saturation at hypoxia, whereas both genetic and developmental factors seem to be important for residual volumes.