Residential altitude affects the risk of sudden infant death syndrome (SIDS) in infants, with higher altitude associated with an increased risk of SIDS.
David Katz, MD, of the University of Colorado School of Medicine, and colleagues conducted a retrospective cohort study of birth and death registries in Colorado from 2007 to 2012, determining infant residential altitude from maternal residential address. The researchers also evaluated the impact of the Back to Sleep campaign to assess the association between sleep position and altitude.
In total, 393,216 infants born between 2007 and 2012 were included, 51.4% of which were boys (mean birth weight 3194 ± 558 g). No meaningful differences were found among the material population. Of the cohort, 79.6% resided at an altitude <6,000 feet, 18.5% resided at an altitude between 6,000 and 8,000 feet, and 1.9% resided above 8,000 feet.
Compared to those who resided below 6,000 feet, infants who resided above 8,000 feet had a higher adjusted risk of SIDS (odds ratio 2.30; 95% confidence interval 1.01–5.24). The researchers also found that following the Back to Sleep Campaign, incidence of SIDS in Colorado dropped from 1.99/1000 live births to 0.57/1000 live births — an effect seen across all different altitudes.
Theories of sudden infant death syndrome (SIDS) suggest hypoxia is a common pathway. Infants living at altitude have evidence of hypoxia; however, the association between SIDS incidence and infant residential altitude has not been well studied.
We performed a retrospective cohort study by using data from the Colorado birth and death registries from 2007 to 2012. Infant residential altitude was determined by geocoding maternal residential address. Logistic regression was used to determine adjusted association between residential altitude and SIDS. We evaluated the impact of the Back to Sleep campaign across various altitudes in an extended cohort from 1990 to 2012 to assess for interaction between sleep position and altitude.