Nutritional, developmental, and genetic influences on relative sitting height at high altitude

Abstract

The study explores how nutritional status, developmental exposure to high-altitude hypoxia, and genetic ancestry influence relative sitting height in two groups of high-altitude Bolivian children aged 8 through 13 years of age: 253 rural Aymara children of very low socioeconomic status and 273 children of upper socioeconomic status from the capital city of La Paz. The rural Aymara children on average have longer trunks relative to stature, but there is also overlap in body proportions between the two groups of children. The 20% of each sample in the region of overlap was examined to investigate influences on relative sitting height. Nutritional effects on relative sitting height are suggested by the finding that Aymara children with relatively long legs are taller, heavier, and fatter than other Aymara children. Developmental and genetic influences on relative sitting height are suggested by the finding that high relative sitting heights in elite urban children are associated with a greater percentage of time lived at high altitude and with parents born in Bolivia. Separating developmental and ancestry effects is difficult because the two are closely interconnected in the urban children. The results of this study suggest that influences on growth in relative trunk and leg length are similar to those that affect other aspects of growth in Andean populations. They also highlight the fact that because relative sitting height gradually decreases prior to adolescence and then increases, the interpretation of variation in body proportions in children is not always straightforward.

Chest circumference and sitting height among children and adolescents from Lhasa, tibet compared to other high altitude populations

“…While Andean trunk length may be influenced by genetic ancestry (Stinson, 2009), it is becoming increasingly clear that body shapes are also influenced by nutritional effects on linear growth (Frisancho, 2007). Because relative sitting height is indicative of stress during growth, similar sitting-height-to-stature ratios among Andeans and Tibetans may reflect similar living conditions.…”

“…Sitting height and chest circumference serve as morphological indicators of thorax growth at high altitude, and both are affected by hypoxia and nutrition during development (Brutsaert et al, 2004;Stinson, 2009). Frisancho (1969) found both sitting height and sternum length were correlated with vital capacity in high-altitude Andeans, though those variables were not as strong predictors of lung volume as was chest circumference at maximum inspiration.…”

Trade-Offs in Relative Limb Length among Peruvian Children: Extending the Thrifty Phenotype Hypothesis to Limb Proportions

“…Differences have been most clearly documented between populations of African or Australian ancestry compared with those of European or Asian ancestry (Native American groups being considered most similar to the latter) [55]–[57], but overall genetic differences probably account for a small proportion of variation (∼3.6%) in relative sitting height (head-trunk height relative to stature) among world populations [25], [57]. Unfortunately, there is little indication in the literature as to the extent of any genetic effects on the body proportions of Andeans (or any populations for that matter), and correlations between ancestry, socioeconomic position and altitude make the specific impact of genetic ancestry difficult to detect.…”

Stunting and the Prediction of Lung Volumes Among Tibetan Children and Adolescents at High Altitude

“…have been attributed to developmental and/or genetic effects on thorax growth in a hypoxic environment (Frisancho et al, 1997;Brutsaert et al, 1999), and sitting-height-to-stature ratios may also have a genetic component (Stinson, 2009). However, the extent to which stunting may cause differences in body proportions among high altitude children, and whether such differences are associated with differences in lung volumes has not been studied.…”