A comparison of chest morphology in high altitude Asian and Andean populations.
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Adaptation, Physiological↗
Biomedical subjects
C M Beall
Publications and source records attributed to C M Beall.
Optimal birthweights in Peruvian populations at high and low altitudes.
This study tests the hypothesis that optimum birthweight for survival is lower among hospital-born infants in Puno, Peru (altitude 3860 m) than that among their counterparts at low altitude in Tacna, Peru (altitude 600 m). The data are derived from hospital birth records for 1971 and 1972 and municipal death records for 1971 through 1973. Linking these records permits analysis of the patterns of mortality in relation to birthweight. Stabilizing selection upon birthweight is operating in both populations. The high altitude population has a lower mean birthweight and a lower optimal birthweight. The Puno population is closer to its optimal birthweight distribution and, as a result of mortality during infancy, is approaching its optimum birthweight distribution for survival more rapidly than the Tacna population. It appears that the high altitude Puno population may well be adapted to its environment in the sense that there is less selective mortality on birthweight phenotypes.
Altitude↗
The effects of high altitude on adolescent growth in southern Peruvian Amerindians.
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Adolescent↗
Growth in a population of Tibetan origin at high altitude.
The report describes height, weight and triceps skinfold measurement for 239 individuals from 5 to 22 and 30 to 39 years of age living in the rural Tibetan village of Mugu, Nepal (altitude 3800m). It compares this population with a high-altitude Andean Quechua population and another high-altitude Tibetan population. A delay in height and weight is manifested by the Mugu population. Mugu children are shorter and lighter than the high-altitude Quechua sample during childhood and the early teens, yet they eventually achieve similar adult heights and weights. Mugu males are shorter and lighter than another Tibetan male sample. The reasons for the contrasting growth patterns are not known precisely due to present lack of thorough nutritional, epidemiological and genetical studies from Mugu.
Adolescent↗
Ages at menopause and menarche in a high-altitude Himalayan population.
Women in a Tibetan speaking population living at 3250-3560 m in Upper Chumik, Nepal, have median ages at menopause and menarche of 46.8 and 16.2 years, respectively, assessed by the status quo technique. Recalled ages at menopause and menarche yield similar results and suggest a long-term existence of a pattern of relatively accelerated age at menopause and delayed age at menarche. Variation in the length of the calculated biological reproductive span in this sample is more strongly associated with recalled age at menopause than recalled age at menarche. The age at menopause in Upper Chumik is accelerated relative to that reported for Western industrial populations; however, these data do not permit drawing conclusions about the reasons underlying the acceleration.
Adolescent↗
Salivary testosterone concentration of Aymara men native to 3600 m.
This paper explores the possibility that variation in the normal physiological range of testosterone concentration modulates men's adaptation to hypobaric high-altitude hypoxia through stimulating haemoglobin production and/or causing respiratory disturbances and exacerbated hypoxaemia during sleep. These effects of testosterone are observed clinically at sea level and have potentially opposing consequences at high altitude, the former perhaps enhancing and the latter diminishing the effectiveness of adaptations to hypoxia. Seventeen young (average age 27 years) and 22 older (average age 57 years) healthy adult high altitude native Aymara men tested at 3600 m have average morning salivary testosterone concentrations of 282 and 241 pmol/l, respectively. The 31 urban men of both age groups have higher testosterone concentrations than the eight rural men and have mean haemoglobin concentrations significantly 0.7-1.0 g/dl higher within the normal high-altitude range, consistent with known effects of testosterone at sea level. Older urban men have slightly more frequent respiratory disturbances during sleep, associated with significantly greater hypoxaemia. There appear to be modest benefits to testosterone concentrations in the upper end of the observed range; however, the direction of these responses towards more haemoglobin production and more hypoxaemia during sleep of older men suggests the hypothesis that very high testosterone concentrations such as those in the upper ranges of sea level values could compromise adaptation to high altitude, particularly among older men.
Adult↗
Blood pressure variation among Ethiopians on the Simien Plateau.
This report presents information on determinants of blood pressure variation in a rural sample of 263 Ethiopian highlanders 14-86 years of age, resident at 3530 m on the Simien Plateau. Mean systolic and diastolic blood pressures for males and females were 109/ 75 and 106/73, respectively, and there were no age differences. These findings confirmed that men and women can have low normal blood pressure throughout adulthood. Blood pressures increased with increasing body mass index (BMI) among adult males, although the mean BMI of 19.1 kg/m2 was low compared with US values. This illustrates that BMI variation may be associated with blood pressure variation in men even at low mean values of both. Blood pressure did not vary with adult haemoglobin concentration.
Adolescent↗