Michael Emery, PhD, from the University of Washington, and colleagues tested estrogen and testosterone levels in the blood serum of 127 infants who had died of SIDS and 42 infants who had died of other causes of unexpected infant death. They found that the testosterone levels in the male SIDS infants were 120% higher than in male non-SIDS infants and 50% higher in female SIDS infants than in female non-SIDS infants. Estrogen levels were not different among the SIDS and non-SIDS infants.
"These results may be important for better understanding of SIDS because the known relationship between testosterone and breathing during sleep provides a mechanism that potentially contributes to SIDS," says Dr. Emery. Previous studies have indicated that higher levels of testosterone may result in depressed breathing during sleep, which in turn may increase the risk of SIDS.
The study is reported in "Serum Testosterone and Estradiol Levels in Sudden Infant Death" by Michael J. Emery, PhD, Henry F. Krous, MD, Julie M. Nadeau-Manning, MSW, Brett T. Marck, BA, and Alvin M. Matsumoto, MD. The article appears in The Journal of Pediatrics, Volume 147, Number 5 (November 2005), published by Elsevier.