Origin of the Nuñoa, Perú High Altitude Field Research Site and How It Shaped Our Understanding of Functional Adaptation to High-Altitude Stressors

Abstract

The study of physical growth and development of Indigenous children from Nuñoa, Perú, in the 1960s showed that growth in body size and skeletal maturation was slow and delayed, while growth in lung volume, measured by forced vital capacity (FVC), was accelerated. Hence, I proposed that the high functional adaptation of high-altitude natives was influenced by developmental processes. To test this hypothesis, my co-investigators and I conducted two sets of major physiological studies at high altitudes. The first studies were conducted in Cusco (3400 m) and Puno (3840 m), Perú. This research showed that the FVC and aerobic capacity of low-altitude Peruvian urban natives acclimatized to high altitudes during the developmental period were similar to those of high-altitude urban natives. In contrast, Peruvian and US participants acclimatized during adulthood did not have the same FVC and aerobic capacity as the high-altitude urban natives. The second set of studies was carried out in the city of La Paz, Bolivia (3752 m), and included Europeans who were acclimatized to high altitudes at different ages. This research confirmed that acclimatization during the developmental period was a major component of the high functional adaptation among high-altitude urban natives. These conclusions have been confirmed by epigenetic studies, which demonstrated that acclimatization to high altitude leads to modifications in the activity of the DNA that facilitate adaptation during the developmental period.

FIGURE 1

A. Roberto Frisancho (on the right) meeting Paul T. Baker at the Cusco, Perú airport in May 1961. This encounter marks the start of research on human bio‐cultural adaptation in Nuñoa, Perú.

FIGURE 2

Slow growth of children from Nuñoa expressed as a percent of adult body height. Growth in body height of both males and females is slow and delayed compared to low‐altitude references. Source: Adapted from: Frisancho and Baker (1970).

FIGURE 3

Growth in lung volume and its relationship to chest circumference in Nuñoa. The development of the size of the lungs is accelerated, which in turn is related to an enhanced chest size. Source: Adapted from: Frisancho (1969).

FIGURE 4

Role of developmental adaptation on the attainment of an enhanced lung volume at high altitude. Low‐altitude natives acclimatized during growth had a similar lung volume as the high‐altitude natives. In contrast, the Peruvian and US low‐altitude natives acclimatized as adults attained significantly lower FVC than the high‐altitude natives. Source: Adapted from: Frisancho, Velasquez et al. (1973); Frisancho (1975).

FIGURE 5

Influence of growth at high altitude on the attainment of high aerobic capacity at an altitude of 3400 m. Participants who acclimatized to high altitude during the developmental period attained similar aerobic capacities as the high‐altitude urban natives. In contrast, the participants from Perú and the United States who acclimatized during adulthood had lower aerobic capacity than the high‐altitude urban natives. Source: Adapted from: Frisancho, Martinez et al. (1973); Frisancho (1975).

FIGURE 6

Influence of developing at high altitude on the attainment of high residual lung volume in (a) males and (b) females. European males and females acclimatized to high altitude during the developmental period attained similar residual lung volume as the high‐altitude urban natives from Bolivia, and greater lung volume than those acclimatized during adulthood. Source: Adapted from: Frisancho et al. (1997).

FIGURE 7

Influence of developmental adaptation on the attainment of high aerobic capacity in (a) males and (b) females. European males and females acclimatized to high altitude during the developmental period attained similar aerobic capacity as the urban natives from Bolivia, and greater aerobic capacity than those acclimatized during adulthood. Source: Adapted from: Frisancho et al. (1995).

FIGURE 8

Overview of the role of developmental adaptation to high altitude. Growth at altitude is an important factor that contributes to the attainment of full functional adaptation to high altitude.