Heritability of daytime cortisol levels and cortisol reactivity in children

Abstract

SummaryIndividuals differ widely in cortisol output over the day and cortisol reactivity to challenge, both of which are relevant to disease risk. There is limited evidence concerning the heritability of these differences, so we evaluated the heritability of cortisol levels in the afternoon and cortisol reactivity using a twin design. The study involved 80 monozygotic (MZ) and 70 dizygotic (DZ) same-sex twin pairs aged 11.2 years on average. Salivary cortisol was measured in the afternoon at home before and after playing a computer game. Ratings of excitement and upset were also obtained, and objective task performance was assessed. Salivary cortisol levels averaged 4.08 (S.D. 2.3) nmol/l at pretask baseline, and declined on average over the session to 3.45 (1.9) nmol/l immediately after the tasks and 2.87 (1.6) nmol/l 10 min later. There were, however, marked individual differences, with cortisol reactivity (difference between pretask baseline and post-task 1) ranging from +4.53 to −6.23 nmol/l. Intra-class correlations for all the cortisol parameters were substantially greater for MZ (range 0.41–0.57) than for DZ (0.11–0.29) twin pairs. Quantitative genetic modelling confirmed significant heritability for pretask baseline cortisol (58%), the two post-task values (60 and 56%), and cortisol reactivity (44%). The study lacked power for assessing sex differences. Subjective reports of excitement were also somewhat heritable, but there was little covariation of cortisol and subjective responses, so genetic influences on covariation could not be tested. These findings indicate that individual differences in children’s cortisol levels recorded before tasks and cortisol reactivity to behavioural challenges are influenced by genetic factors.

Evidence for the stress-linked immunocompetence handicap hypothesis in human male faces

“…Our results support this interpretation as, in humans, peak C is heritable (e.g. [42]) and suppresses the immune system (e.g. [38]).…”

Nonsynonymous HTR2C polymorphism predicts cortisol response to psychosocial stress I: Effects in males and females

“…Research investigating neuroendocrine reactivity to laboratory-induced stress has demonstrated that risk factors for depression predict dysregulated cortisol responding to psychosocial stress (e.g., Oswald et al, 2006; Wirtz et al, 2007) and that genetic factors account for a moderate amount of variance in cortisol reactivity (Federenko, Nagamine, Hellhammer, Wadhwa, & Wüst, 2004; Steptoe, van Jaarsveld, Semmler, Plomin, & Wardle, 2009). Furthermore, lab-induced psychosocial stress has been used to demonstrate gene-environment (GxE) interactions (e.g., Miller, Wankerl, Stalder, Kirschbaum, & Alexander, 2013) that meta-analytic evidence suggests also occur naturalistically (Karg, Burmeister, Shedden, & Sen, 2011).…”

Relationships between diurnal adrenocortical activity, children’s attachment security and mothers’ attachment representations

“…The new results presented here suggest that children's attachment quality has an impact both on children and mother physiology. Previous research has shown that the emotional state of the mother is mirrored both on their own cortisol levels, as well on their children's, probably due to genetic similarities and similar environmental conditions (Spangler, 1991;Stenius et al, 2008;Steptoe et al, 2009). …”