Browsing by Autor "Obert, P"

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Effect of chronic hypoxia and socioeconomic status on the maximal oxygen uptake of 10- to 12-year-old Bolivian boys
(Facultad de Medicina, Enfermería, Nutrición y Tecnología Médica, 1994) Obert, P
Abstract. The aim of this study was to analyze the effect of altitude and socioeconomic status on the maximal oxygen uptake (VO₂max) of prepubertal Bolivian boys. The subjects were 143 prepubertal boys (10 to 11.5 years old) living in La Paz (altitude 3600 m, n = 67) and Santa Cruz de la Sierra (altitude 420 m, n = 76). At high altitude, 23 boys were from a high socioeconomic status (HAHSES) and 44 from a low socioeconomic background (HALSES). At low altitude, 29 boys were from a high socioeconomic level (LAHSES) and 47 from a low socioeconomic background (LALSES). Anthropometric characteristics were determined in order to assess the physical growth of the boys. The VO₂max was determined from a progressive maximal exercise (direct method). The subjects performed this test using the same cycle ergometer at both high and low altitudes. For the overall anthropometric parameters, there was no significant difference between highland and lowland boys of the same socioeconomic status. However, regardless of altitude, boys from a low socioeconomic background were 2 years behind those from a high socioeconomic background. There was no significant difference for VO₂max between boys from high and low socioeconomic backgrounds at HA (HAHSES: 37.2 ± 5.6; HALSES: 38.9 ± 6.4ml.min-1 .kg-1 body weight) and at LA (LAHSES: 42.6 ± 5.4; LALSES: 43.1 ± 4.9 ml . min-1 . kg-1 body weight). The VO₂max of highland boys was, on average, 11% lower than that of lowland boys. It appears, therefore, that a difference in socioeconomic status has no effect on the VO₂max (ml. min-1 . kg-1) of prepubertal children at low altitude as well as the altitude of 3600 m.
The importance of socioeconomic and nutritional conditions rather than altitude on the physical growth of prepubertal Andean highland boys
(Facultad de Medicina, Enfermería, Nutrición y Tecnología Médica, 1994) Obert, P
Summary. The aim of this work was to study the effect of hypoxic stress on the physical growth of prepubertal Bolivian boys (10-11.5 years of age) of the same socioeconomic and nutritional conditions. The subjects consisted of 143 boys living in La Paz (altitude 3600m, n = 67) and Santa Cruz de la Sierra (altitude 420m, n = 76). Among the boys studied at high altitude, 23 were from a high socioeconomic background (HA1) and 44 from a low socioeconomic background (HA2). The group studied at low altitude consisted of 47 boys from a high socioeconomic background (LA1) and 29 from a low socioeconomic background (LA2). A scientific evaluation of the nutritional status of the boys was realized from specific anthropometric characteristics (height, body weight, upper arm muscle circumference, body fat mass and body mass index) and haematological (haematocrit, haemoglobin, serum iron, serum ferritin, red cell protoporphyrin, transferrin saturation) and biochemical (total serum protein, albumin and prealbumin) parameters. At high as at low altitudes, the biometric characteristics of boys from a low socioeconomic background were significantly lower than those of boys from a high socioeconomic background. The physical growth of HA2 and LA2 boys was delayed by approximately 2 years. All the boys had biochemical and haematological parameters within the normal range. Boys from a low socioeconomic background were considered as marginally undernourished and those from a high socioeconomic background as well-nourished. Within the same socioeconomic class there was no nutritional difference between highland and lowland boys. Similarly, and this is the most important feature of this study, there was no difference for the overall biometric characteristics between highland and lowland boys of the same socioeconomic and nutritional status. Therefore, it appears that when socioeconomic and nutritional conditions are taken into account, there is no effect of hypoxic stress on the physical growth of prepubertal Andean highland boys.