GP80\u2005Once more about customized versus population-based growth charts: how to assess physical development of the indigenous children of the north?

Abstract

Introduction Despite evidence of race/ethnic differences in growth, the WHO’s position nowadays is based on the understanding that all children who were breastfed as infants, grow similarly and a single set of charts can be used to judge growth in any child. The population-based growth charts (PBGC) in assessing physical development of the indigenous children of the North (ICN) lead to ambiguity: pediatricians must recommend correcting their diet because of malnutrition, but to change the diet means to face many associated health issues. The aim of this study is to assess the appropriateness of PBGC for monitoring of growth of ICN. Methods We compared the dynamics of body weight, height, body mass index and arterial pressure of the Nenets, Khanty, Komi and Slavic children – inhabitants of the Yamal-Nenets Autonomous region (n=5940, age 3 – 17 years) as well as of the Sakha, Slavic and 5 ethnic groups of ICN living in Yakutia (n=278793, age 0 – 17 years). For some of them, the dimensions of inner organs (sonography) and salt taste sensitivity were also analyzed. We used standard methods of parametric statistics. Results We revealed that in most ICN the body length and mass, being at birth the same or higher than in non-indigenous folks, after the age of 3 years became significantly lower. Both systolic and diastolic arterial pressure in Nenets children become lower than in non-original settlers beginning from the age of 10 years although the arterial pressure in ICN living in Yakutia is higher than in non-original settlers beginning from the pre-school age. There are also differences in salt taste sensitivity (in some groups of ICN lower) as well as in the sonographically determined liver (in ICN bigger) and in the aorta (in ICN wider) sizes. Conclusions Understanding that racial/ethnic-specific charts are now not recommended because the differences in growth among racial/ethnic groups are shown to be the result of environmental rather than genetic influences, we still must conclude that PBGC may not be optimal for ICN. Customized growth charts adjusted for race/ethnicity are more appropriate. Further research is needed to investigate the benefits and harms of using customized charts for monitoring the growth of ICN. The use of a single standard in ICN is not justified and the claim that ‘child populations grow similarly across the world’s major regions when their needs for health and care are met’ is probably just an assumption.