The Sleep Homeostatic Response to Sleep Deprivation in Humans is Heritable


 
 
 Following sleep deprivation, increases in delta power have historically been used to index increases in sleep pressure. Research in mice has demonstrated that the homeostatic delta power response to sleep deprivation is heritable. Whether this is true in humans is unknown. In the present study, we used delta power and ORP, a novel measure of sleep depth, to investigate the effects of acute sleep deprivation on sleep depth and to assess the heritability of sleep homeostasis in humans.
 
 
 
 ORP and delta power were examined during baseline and recovery sleep following 38 hours of sleep deprivation in 57 monozygotic and 38 dizygotic same-sex twin pairs. Two complementary methods were used to estimate trait heritability of sleep homeostasis.
 
 
 
 During recovery sleep, ORP was lower and delta power was higher than at baseline, indicating deeper sleep. However, at the end of the recovery night, delta power reached baseline levels but ORP demonstrated incomplete recovery. Both ORP and delta power showed broad sense heritability of sleep homeostasis following sleep deprivation. The classical approach demonstrated an h 2 estimate of 0.43 for ORP and 0.73 for delta power. Mixed-effect multilevel models showed that the proportion of variance attributable to additive genetic transmission was 0.499 (95% CI 0.316 to 0.682; p<0.0001) for ORP and 0.565 (95% CI 0.403 to 0.726; p<0.0001 for delta power.
 
 
 
 These results demonstrate that that the homeostatic response to sleep deprivation is a heritable trait in humans and confirm ORP as a robust measure of sleep depth.
