New research found that babies who live at higher elevations, specifically those that rise above 8,000 feet (2,438 meters), may face a slightly higher risk of Sudden Infant Death Syndrome, otherwise known as SIDS. However researchers caution parents not to panic about these new findings.
"The absolute risk [of SIDS] remains very low, and ... this is in no way a call to abandon residence [in] or visits to high-altitude" locations, said study researcher Dr. David Katz, a cardiologist at the University of Colorado Denver.
However the research does suggest that lower oxygen levels might play a role in SIDS, a finding that could hint at the cause of tragic, unexplained infant deaths.
For the new study, Katz and his colleagues gathered data from birth certificates and death certificates for all births and deaths in Colorado between 1990 and 2012. The state has the highest elevation, on average, of any state in the United States. These elevations range from 3,315 feet above sea level to 14,433 feet above sea level, the researchers said.
The team then excluded infants born with known defects and infants born between 1994 and 1996, when the Back to Sleep campaign was just starting. This gave researchers two clear pre- and post- campaign groups to compare. Next they separated the infants into groups based on elevation: less than 6,000 feet, between 6,000 and 8,000 feet, and above 8,000 feet.
Researchers found that there was no difference in SIDS risk between babies living at less than 6,000 feet compared to those living at 6,000 to 8,000 feet. However, above 8,000 feet, that changed. Between 2007 and 2012, there were 0.42 deaths of infants for every 1,000 live births from SIDS. However, in the group above 8,000 feet, this number rose to 0.79 SIDS deaths for every 1,000 live births.
"At higher altitude, there is greater absolute risk of SIDS," Katz told Live Science. Cities at above 8,000 feet in Colorado include ski towns such as Vail, Winter Park and Breckenridge, as well as mountain towns such as Leadville, Silverton and Fairplay.
Researchers also found the Back to Sleep campaign worked in the higher elevations as well. Putting to babies to sleep on their backs, as hard as that can be at times, can lower the risk of SIDS across the board.
"I think it's important to point out that parents can still focus on modifiable risk factors for sudden infant death syndrome, including putting infants on their back to sleep, avoiding excessive blankets or stuffed animals, and maintaining a no-smoking environment," Katz said.
"I would like parents to feel that they're empowered to take some very concrete steps to minimize risk of SIDS wherever they live," study co-author Dr. Susan Niermeyer, a professor of pediatrics at the University of Colorado School of Medicine, told Live Science. Breastfeeding and sleeping in the same room as an infant can also reduce SIDS risk, she said.
Katz and his team also cautioned that their study was purely observational, and they aren't sure why the elevation appears to be linked to SIDS. "I'm going to resist the urge to speculate," Katz said.
