ESPE Yearbook of Paediatric Endocrinology

To read the full abstract: Front. Endocrinol. 2020; 11:106. doi: 10.3389/fendo.2020.00106

• The authors assessed the relationship between markers of a stressful environment and final height in adult men and women in 71 countries (including 31 countries that are members of the Organisation for Economic Co-operation and Development [OECD]).• They found that the more stressful the environment, the shorter the adult height.• By order of decreasing importance, the relationship between markers of a stressful environment and height were income inequality > air pollution > growth domestic product > corruption perception index > homicide rate > life expectancy > unemployment.

Overall, this interesting article suggests that the better the environment (defined by 7 equally weighted indicators of a stressful environment: homicide rates, growth domestic product per capita, income inequality, corruption perception index, unemployment rate, urban air pollution and life expectancy), the greater the final adult height. The authors consider the relationship between environment and height at the global level and rank final height according to published characteristics of each country. Several comments come to mind. First, they mention that the within-country variability is similar to the between-country variability. However, published data do not make it possible to determine whether the within-country variability is affected by the same stressors as the between-country variability. For instance, within a country, are children less affected by an adverse environment growing faster then those more affected by these stressors? Second, it is important to understand the relationship between qualitative and quantitative nutrition, a key determinant of linear growth, and the various environmental markers used in this study. For instance, is income inequality affecting growth because poorer people have less money to buy food or because they live in less desirable areas where air pollution is higher, chronic diseases more common and psychological stress due to lack of safety greater? The most likely assumption is that it may be a combination of several factors. Third, the study focuses on final height as a marker for growth in childhood and adolescence, but it is also conceivable that this growth is affected by prenatal factors (maternal environment) and opens the door to the concept of transgenerational effect of stress. Finally, at the individual level, short stature is one of the most common reasons why patients are referred to a pediatric endocrinologist. Although pediatric endocrinologists are asked to rule our hormonal deficiency or excess as a cause of short stature, they are well aware that height variation results from a complex interaction between genetic, environmental, socioeconomic, and cultural factors. An example relevant to this article is psychosocial short stature, which is caused by stress and emotional deprivation in children (usually within the family), is associated with low height velocity (that increases back to normal once the stressors are removed) and, provided that the stressors are removed early enough in life, with normal or near normal final height. It is thought to be mediated at least in part by functional, reversible growth hormone deficiency secondary to hypopituitarism and is mostly independent from nutrition. At the clinical practice level, this article is a reminder to have a broad approach when assessing a patient for short stature.