Chest depth, chest width, forced vital capacity (FVC), and forced expiratory volume (FEV1) were measured in 170 adult males differing by ancestral (genetic) and developmental exposure to high altitude (HA). A complete migrant study design was used to study HA natives (Aymara/Quechua ancestry, n = 88) and low altitude (LA) natives (European/North American ancestry, n = 82) at both altitude (La Paz, Bolivia, 3,600 m) and near sea level (Santa Cruz, Bolivia, 420 m). HAN and LAN migrant groups were classified as: Nth generation migrants, born and raised in a non‐native environment; child migrants who migrated during the period of growth and maturation (0–18 yrs); and adult migrants who migrated after 18 years of age. Chest depth, FVC, and FEV1 measures were larger with increasing developmental exposure in both HAN migrants at LA and LAN migrants at HA. Developmental responses were similar between HAN and LAN groups. FVC and FEV1 measures were larger in HANs vs LANs born and raised at HA to suggest a genetic effect, but were similar in HANs and LANs born and raised at LA. The similarity of HAN and LAN groups at LA suggests that the genetic potential for larger lung volumes at HA depends upon developmental exposure to HA. Additional data for females (HANs at HA, n = 20, and LAN adult migrants to HA, n = 17) show similar differences as those shown between male HAN and LAN groups. Am. J. Hum. Biol. 11:383–395, 1999. © 1999 Wiley‐Liss, Inc.

Progesterone levels appear to be influenced by chronic and acute ecological conditions, evidenced by the association with body-size and the probability of ovulation respectively. These findings have implications for understanding cancer aetiology, developing population-appropriate hormonal contraceptives, and modelling the evolution and functioning of the reproductive system.

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The forced vital capacity (FVC), forced expiratory volume in one second (FEV), and ratio of FEV to FVC (%FEV) of 161 male and 158 female youths of European ancestry who were born at high altitudes and who were residing in La Paz, Bolivia (average altitude of 3,600 m) were examined and compared with those for lowland Europeans and highland Aymara Amerindians. FVC and FEV were significantly larger (p less than .001) in the La Paz Europeans than in two lowland control samples of European ancestry, with the relative differences between samples varying from small (1.5-4.1%) to moderate (7.7-11.9%). It could not be determined whether the enhanced lung volumes of the La Paz European children were acquired through an accelerated development of lung volumes relative to stature during adolescence, as is the case for Amerindian highlanders. After controlling for body and chest size, FVC and FEV were significantly smaller in the La Paz Europeans than in highland Aymara (p less than .001), suggesting that the lung volumes of the Aymara are influenced by factors other than simply growth and development at high altitude. Finally, as found in Amerindians, chest size is an important determinant of intra-individual variation in lung function among highland Europeans.

Mechanisms underlying sex-related differences in adaptation to high altitude were investigated by assessing the turnover of dopamine and noradrenaline in structures of the chemoafferent pathway, i.e. carotid body and brainstem noradrenergic cell groups (A1, A5, A6, A2 to which chemosensory fibres project). The influence of gender was assessed in male and female rats reared at an altitude of 3600 m, whereas the influence of endogenous sex hormones was evaluated by castration. Haematocrit, red blood cell count and plasma erythropoietin levels were lower in females than in males (-5%, -15%, -53%, respectively). Dopamine and noradrenaline turnover were higher in female structures (carotid body: +51%; A2: +140%; A1: +54%; A5: +27%). Dopamine and noradrenaline turnover in carotid body and brainstem cell groups were differently affected by castration, i. e. enhanced by orchidectomy (carotid body: +134%; A2: +120%; A1: +69%; A5: +67%) but inhibited by ovariectomy (carotid body: -33%; A2: -92%). Orchidectomy elicited a reduction in haematocrit (-10%), haemoglobin concentration (-8%) and red blood cell count (-24%), whereas haematological status remained unaltered after ovariectomy. Therefore, both gender and endogenous sex steroids may control catecholamine activity differently in structures involved in the chemoafferent pathway, thus providing a neurochemical basis for sex-related differences in adaptation to hypoxia.