摘要：Objectives. This study sought to determine whether the short stature of Mapuche children, an indigenous group in Chile, reflects poverty or genetic heritage and whether the international reference population, derived from studies of US children of mostly European origin, is appropriate for assessing growth failure in indigenous peoples of the Americas. Methods. The study assessed 768 schoolchildren of Mapuche and non-Mapuche ancestry, aged 6 to 9 years, living under conditions of extreme, medium, and low poverty. Results. Growth retardation was strongly related to poverty in both ethnic groups. Within poverty levels, there were no significant differences in stature between ethnic groups, and in low-poverty areas in Santiago, the capital city, mean stature was only slightly less than in the reference population. Conclusions. Poverty, not ancestry, explains the short stature of Mapuche children, and use of the international reference to assess growth in this population is appropriate. Many Latin American countries, such as Mexico, Guatemala, Bolivia, Peru, and Ecuador, have large indigenous populations. These groups are generally the poorest and least educated, as well as the most growth retarded or stunted. 1, 2 The question arises whether the high levels of stunting recorded among indigenous peoples are a result of poverty or are also (or instead) indicative of bias introduced by using an inappropriate reference population—that is, by using the National Center for Health Statistics–World Health Organization curves, which are derived from studies of US children of Northern European ancestry. 3 If the small size of children of indigenous origin relative to Northern Europeans is the result of genetic differences in growth potential, the use of the current reference may overestimate the extent of true stunting. This is an important question for many Latin American countries, because the prevalence of stunting is commonly used to define the problem of malnutrition, to identify the groups most affected, and to allocate resources. The work of Habicht et al. 4 established that child stature at 7 years of age differs substantially between the highest and lowest socioeconomic levels of many countries. On the other hand, children of well-off families from various countries in Asia, Africa, and Latin America were found to be very similar in size to each other and to children of European origin. These authors concluded that differences in child size associated with social class were marked and many times larger than those that might be attributed to ethnic differences. This seminal article 4 provided strong justification for the use of the current reference to assess the status of children worldwide. Guatemala was one of the countries included in the analyses. A criticism of the approach of Habicht and colleagues is that social class distinctions in Guatemala reflect differences not only in wealth but also in ancestry, which is largely Spanish at the top of the social order and largely indigenous at the bottom. For Guatemala, as well as other Latin American countries, a more apt comparison would have been the growth of indigenous children vs that of nonindigenous children from families along the socioeconomic gradient. This was not done by Habicht et al., nor has it been done by anyone else, for the simple reason that few indigenous people have attained high socioeconomic status—a sobering social comment. About 7% of the population of Chile is of indigenous ancestry, of which the Mapuche (also referred to as Araucanos) are the largest group. 5 The Mapuche inhabit the south central part of the country. Chile has experienced rapid economic and social development in recent years and this has brought significant improvements in the general standard of living. 6 Also, Chile has one of the best public health systems of the region, with many health and nutrition programs targeted at the poor. 7 Nevertheless, the Mapuche continue to be one of the poorest groups in the country, despite improved living conditions. The situation in Chile permits studying the size of Mapuche children of various social classes. Consequently, the objective of this study was to compare the heights of indigenous and nonindigenous children aged 6 to 9 years at various levels of the socioeconomic gradient. The general hypothesis tested was that poverty, not ancestry, accounts for the short stature of Mapuche children. The specific hypotheses tested were as follows. Going from extreme to low levels of poverty, height increases among indigenous and nonindigenous groups. Height does not differ between indigenous and nonindigenous children within poverty levels. In areas with the lowest levels of poverty, the heights of indigenous and nonindigenous children will not differ from that of the international reference population.
