BACKGROUND: @entity701 is the primary output of the @entity2339 and is central to the biological stress response, with wide-ranging effects on @entity146 health. Despite well-studied biological pathways of glucocorticoid function, little attention has been paid to the role of genetic variation. Conventional salivary, urinary and serum measures are strongly influenced by diurnal variation and transient reactivity. Recently developed technology can be used to measure @entity701 accumulation over several months in hair, thus indexing chronic HPA function. METHOD: In a socio-economically diverse sample of 1070 twins/multiples (ages 7.80-19.47 years) from the Texas Twin Project, we estimated effects of sex, age and socio-economic status (SES) on hair concentrations of @entity701 and its inactive metabolite, @entity821 , along with their interactions with genetic and environmental factors. This is the first genetic study of hair neuroendocrine concentrations and the largest twin study of neuroendocrine concentrations in any tissue type. RESULTS: Glucocorticoid concentrations increased with age for females, but not males. Genetic factors accounted for approximately half of the variation in @entity701 and @entity821 . Shared environmental effects dissipated over adolescence. Higher SES was related to shallower increases in @entity701 with age. SES was unrelated to @entity821 , and did not significantly moderate genetic effects on either @entity701 or @entity821 . CONCLUSIONS: Genetic factors account for sizable proportions of glucocorticoid variation across the entire age range examined, whereas shared environmental influences are modest, and only apparent at earlier ages. @entity998 appears to be more consistently related to biological sex, age and genotype than to experiential factors that cluster within nuclear families.

Genetic influences on hormonal markers of XXXX in human hair.

@entity821 :: ('MESH:D003348', 'Chemical') :: ['cortisone'] @entity998 :: ('MESH:D002303', 'Disease') :: ['Chronic glucocorticoid output'] @entity146 :: ('MESH:D001523', 'Disease') :: ['psychiatric'] @entity2339 :: ('MESH:D007029', 'Disease') :: ['hypothalamic-pituitary-adrenal (HPA) axis'] @entity701 :: ('MESH:D006854', 'Chemical') :: ['Cortisol', 'cortisol']
@entity2339 :: (MESH:D007029,Disease) :: ['chronic hypothalamic-pituitary-adrenal function']
