Anthropometric asymmetry in chronically undernourished children from Southern Mexico.

In previous studies, environmental stress has been associated with increased structural asymmetry, indicating differential rates of development on either side of the median plane. To analyse the effect of environmental stress upon anthropometric asymmetry, six bilateral measurements and one derived measurement were compared between chronically mild-to-moderately undernourished school children (7-13 years of age) and a well-nourished control sample (5-35 years of age). The undernourished sample was from a subsistence agricultural community in Southern Mexico. The well-nourished comparison (control) sample was middle class, White children and young adults in Texas. Anthropometric asymmetry of the skeleton was not consistently increased in the undernourished school children compared to the well-nourished controls. Arm and estimated mid-arm muscle circumferences had significantly increased asymmetry, but these differences are likely due more to laterality in function or physical work than to undernutrition. Genetic influences are hypothesized to underlie skeletal asymmetry (i.e. differences in development on either side of the median plane).