Linear growth in weight, stature, sitting height and leg length, and body proportions of Aymara school-children living in an hypoxic environment at high altitude in Chile.

A cross-sectional growth study has been carried out in Aymara Indians who live in the rural community of Putre located in the Chilean Andes at an altitude of 3,530 m. The sample comprises 153 school-children (77 boys and 76 girls), aged 6 to 19 years, who were born and raised at high altitude, well-nourished and healthy. Their weight, stature and sitting height were measured. From these measurements, total leg length, body mass index (BMI), index of corpulence and cormic index were calculated. The results demonstrate that in the Putre Aymara children the adolescent growth spurt for weight, stature, sitting height and leg length occurs earlier in girls than in boys. There is a significant sex dimorphism beginning at 14 years of age and continuing to adulthood with higher means in males. The physique of the Aymara can be characterized by a large body mass relative to stature as shown by the body mass index. High mean values for the cormic index indicate that the Aymara children have relatively short legs. Compared to reference values of the National Center for Health Statistics (NCHS), Aymara children of both sexes are shorter in stature and lighter in weight than US children at nearly all ages. These results are consistent with findings of other authors on Aymara samples from Chile, Bolivia and Peru. However, the Putre Aymara are heavier and taller than most comparative Aymara samples. While the observed inter-ethnic growth differences may be primarily due to differences in oxygen supply as a result of living at different altitudes, the intra-ethnic growth differences could more likely be attributed to dietary factors.