Children born in the highlands are small at birth and impede growth

Children born at high altitudes such as 1,500 m (4,921 ft) above sea level will be smaller at birth and will be at greater risk of stunting than newborns, according to a new study released this week by Ethiopian researchers. It has been shown at lower altitudes. Research published in the latest issue of the journal JAMA Pediatrics..

Research Assumptions and Highlights

The question the researchers sought to answer in this study was whether being born in the highlands would affect linear growth patterns in children. In this large study of over 900,000 children from birth to 5 years (59 months), children born in the highlands had a lower growth trajectory than those born and raised in the lowlands. It was shown. The team found that this “height-dependent growth differential” was significant even when adjusted for other factors, such as the children’s ideal home environment.

what did you do?

The research team writes that genetically distinct children living in an ideal home environment that promotes healthy growth are known to have similar growth potential. This study sought to determine whether altitude affects growth, even when children grew up in an ideal home environment. They wanted to assess the impact associated with the use of the 2006 World Health Organization growth criteria. These standards they wrote have not been tested by communities and residents living at 1500 m above sea level.

In this study, the team included 133 cross-sectional surveys conducted across the country representing different populations. The data was collected from 59 countries and a total of 964,299 height records were collected from 96,552 data clusters. The population studied lived at altitudes of -372 to 5951 m above sea level. The survey was conducted between 1992 and 2018.

The ideal home environment was defined as “access to safe water, sanitation and health care”. Higher altitudes were defined as altitudes above 1500m above sea level. Researchers measured “children’s linear growth deficit” measured in terms of “length of age/age of age” When Score (HAZ). A high level relationship with HAZ was considered for all children living in an ideal home environment. We compared growth trajectories among children living above and below 1500 m above sea level and assessed “height deficits via elevation” using statistical tests such as multivariate linear regression.

What did you find?

Some of the key findings from this large-scale study are:

• About 12% of the world’s population, equivalent to about 842 million people, lived above 1,500 m above sea level in 2010. Over 800 million people live above 1,500 meters above sea level, and two-thirds of them live in sub-Saharan Africa and Asia. Even in the United States, some cities are above 5,000 feet above sea level. Some of these include 37 cities in Butte, Cheyenne, Jackson, Laramie, Flagstaff, Arizona, Las Vegas, Albuquerque Santa Fe, Mammoth Lakes, Big Bear Lake, South Lake Tahoe, Colorado. For example, Aspen, Breckenridge, and Telluride are above 7,000 feet above sea level.
• Most of the highly resident individuals above 1500 m above sea level were from Asia or Africa (67%)
• In this study, 11% of all children from birth to 59 months lived above 1,500 m above sea level.
• The growth trajectory of children born at higher altitudes was significantly lower than the children living at lower altitudes.
• There was a negative linear relationship between altitude and HAZ.
• At altitudes above 1,000 m above sea level, “the HAZ has decreased by 0.163 units (95% CI, -0.205 to -0.120 units),” the team wrote.
• HAZ numbers for children living in an ideal home environment were predicted by the 2006 World Health Organization HAZ distribution. However, this only applies to altitudes up to 500m. Beyond that, the association did not work.

Implication

Researchers have concluded that even in an ideal home environment, children born and living at higher altitudes may grow slower than children who live at lower altitudes. They need to identify and implement interventions that address altitude-mediated growth restriction during pregnancy and early childhood. They added that special attention should be given and guidance should be provided for pregnancy at high altitudes and its management. However, we do not recommend changing elevation-specific 2006 World Health Organization growth criteria.

Hirvonen explained, “Highland pregnancy is always associated with chronic hypoxia, or insufficient oxygen supply, and an increased risk of fetal growth restriction.” Therefore, babies born in the highlands suffer from lack of oxygen at birth. Hirvonen said he had hoped that inheriting genes from ancestors who lived in the highlands for generations would mitigate the effects of the highlands. The reality was different.

“The first step is to unravel the complex relationships that connect altitude, hypoxia, and fetal growth, and to take effective interventions,” said Cariab Bay, director of research at the Food Science and Nutrition Center in Addis Ababa, Ethiopia. Hirvonen said, “If high-altitude children, on average, are stunted more than their peers above sea level, we need more important efforts to tackle high stunting. That’s it.”