Testosterone Levels High in SIDS Infants

Abnormally high testosterone levels may play a part in sudden infant death syndrome, Michael Emery, Ph.D., and colleagues reported.

Their postmortem serum analyses of SIDS infants showed that testosterone levels in some males were comparable to the highest levels reported in living infants (preterm males), and the levels for some SIDS females were more than twice as high as any previously reported levels for any living female infants.

Identifying a link between causality and elevated testosterone will take more study, said Dr. Emery of the University of Miami. But since the hormone decreases ventilation and ventilatory drive during sleep in adults, the researchers postulate a link between hormonal pulses, neuronal excitability, and cardiorespiratory control (J. Pediatr. 2005;147:596–91).

The researchers examined postmortem serum testosterone and estradiol in 127 SIDS infants and 42 control infants who had died unexpectedly, but of known causes. Both male and female controls were significantly older than SIDS infants (males, 155 days vs. 97 days; females, 134 days vs. 86 days).

Testosterone levels were significantly higher in SIDS males, compared with control males (4.8 nmol vs. 2.2 nmol) and in SIDS females, compared with control females (2.4 nmol vs. 1.6 nmol). Estradiol levels did not differ between controls and SIDS infants. Testosterone levels decreased significantly with infant age among male and female SIDS infants but remained steady with age among controls. The difference in testosterone levels between the groups remained significant even when preterm infants (three SIDS and seven controls) were excluded.