A perplexing difference in growth and development in children born at high altitudes was discovered by researchers. They found that many of them were born shorter in length, and had a lower trajectory in growth compared with children who were born at lower altitudes.

In a study "Evaluation of Linear Growth at Higher Altitudes" published in JAMA Pediatrics on Monday, researchers Kalkeab Baye, director of the Center for Food Science and Nutrition in Addis Ababa, Ethiopia, and Kalle Hirvonen, a senior research fellow at the International Food Policy Research Institute, looked at 964 ,299 children living in different countries from 0 to 59 months old. They ascertained that all over the world, more than 800 million individuals are living at an elevation of 1,500 meters above sea level. Two-thirds of this number is found in Asia and Sub-Saharan Africa.

The study pointed out that as per World Health Organization children who lived in "ideal" home environments grew according to standards. This, however, changed the moment that children live at around 500 meters above sea level or approximately 1,650 feet of elevation. The researchers noticed that the height-for-age scores of the children decreased in these areas.

They noted that pregnancy was at the highest risk while living in areas with higher altitudes. Oftentimes, pregnant women experience an inadequate supply of oxygen. This inadequacy is usually associated with an increased risk of restricting fetal growth.

Once the babies were born, researchers compared their growth rate with those born in lower altitudes. They found that children born in high altitudes had a growth curve that was significantly lower.

Baye underscored that following what they have unearthed in their study, the first step is to discover the link between inadequate oxygen and fetal growth to high altitude so that effective interventions may be identified.

Children clamber up a rocky slope towards their meadow school in Kashmir Photo: AFP / Tauseef MUSTAFA

In the U.S., there are a number of cities located at high altitudes. These are Las Vegas, Albuquerque; Butte, Montana; Cheyenne, Jackson; Laramie, Wyoming; and Big Bear Lake, Mammoth Lake, and South Lake Tahoe in California. There are also more than 30 cities in Colorado found in high altitudes. Exceptional are those found 7,000 feet above sea level, which include Aspen and Telluride in Colorado, as well as Santa Fe in New Mexico.