Higher altitude linked to slightly increased SIDS risk: study

Babies who live at high altitude may face a slightly increased risk of sudden infant death syndrome (SIDS), a U.S. study said Monday.

The study, published in the U.S. journal Pediatrics, examined birth and death registries of nearly 395,000 infants in the U.S. state of Colorado from 2007 to 2012, and compared the records with the altitudes of the children' homes.

Colorado is the highest state in the U.S. with elevations ranging from 3,315 feet (1,010 meters) above sea level to 14,433 feet (4,399 meters).

Compared with infants who lived below 6,000 feet (1,828 meters), infants who lived at an altitude higher than 8,000 feet (2,438 meters) had a 2.3 times higher rate of SIDS, according to the study led by David Katz of the University of Colorado Denver.

However, despite doubling the risk, the absolute risk remains very low, it noted. During the six years studied, there were only 0.8 SIDS deaths for every 1,000 infants who lived above 8,000 feet.

The study suggested that high altitude hypoxia, or low oxygen levels, may explain the increased SIDS risk. Hypoxia has been previously cited as a risk factor for SIDS.

SIDS is defined as the sudden unexplained death of an infant less than one year of age. Globally it resulted in about 15,000 deaths in 2013, down from 22,000 deaths in 1990. Endite