Schreiber Jane E, Shirtcliff Elizabeth, Van Hulle Carol, Lemery-Chalfant Kathryn, Klein Marjorie H, Kalin Ned H, Essex Marilyn J, Goldsmith H Hill
Department of Psychology, University of Wisconsin-Madison, 1202 West Johnson Street, Madison, WI 53706, USA.
Psychoneuroendocrinology. 2006 Oct;31(9):1131-7. doi: 10.1016/j.psyneuen.2006.07.005. Epub 2006 Sep 25.
Modest genetic effects on morning, but not late-day, cortisol levels have been established. Environmental demands may influence basal cortisol levels later in the day. Thus, we anticipated that individuals in the same family would have similar afternoon cortisol levels to the extent that they share aspects of their environment. We examined afternoon basal cortisol levels measured across 3 consecutive days in mothers and fathers and in multiple offspring in two separate large and longitudinal studies. Study I involved 321 families with singletons while study II involved 233 families with twins. Modest family similarity was apparent for afternoon basal cortisol levels in both studies. Spouses' cortisol levels were also correlated. Data from study II demonstrated that family resemblance in afternoon cortisol was accounted for by underlying shared environmental factors, but not underlying genetic factors. Shared environment accounted for 62% of the variation in twin afternoon basal cortisol levels and 14% of the variation in parent afternoon basal cortisol levels. We used pooled data from the two studies to examine whether parental depression, socioeconomic status (SES), and offspring sex and age impacted cortisol levels. Female offspring had higher cortisol levels than males, and cortisol decreased with age until about 9 years of age, after which cortisol increased with age. Family similarity persisted after accounting for parental depression, SES, time of day, and offspring sex and age, which suggests that the shared family environment influences parent and offspring stress hormone levels throughout the childhood years.
已证实基因对早晨皮质醇水平有适度影响，但对傍晚皮质醇水平无影响。环境需求可能会影响一天晚些时候的基础皮质醇水平。因此，我们预计同一家庭中的个体在共享环境因素的程度上，下午的皮质醇水平会相似。我们在两项独立的大型纵向研究中，对父母和多个后代连续三天测量的下午基础皮质醇水平进行了研究。研究I涉及321个有独生子女的家庭，而研究II涉及233个有双胞胎的家庭。在两项研究中，下午基础皮质醇水平都明显存在适度的家庭相似性。配偶的皮质醇水平也存在相关性。研究II的数据表明，下午皮质醇的家庭相似性是由潜在的共享环境因素而非潜在的基因因素造成的。共享环境占双胞胎下午基础皮质醇水平变异的62%，占父母下午基础皮质醇水平变异的14%。我们使用两项研究的汇总数据，来检验父母的抑郁、社会经济地位（SES）以及后代的性别和年龄是否会影响皮质醇水平。雌性后代的皮质醇水平高于雄性，皮质醇水平随年龄增长而下降，直到约9岁，此后皮质醇水平随年龄增长而上升。在考虑了父母的抑郁、SES、一天中的时间以及后代的性别和年龄后，家庭相似性依然存在，这表明共享的家庭环境在整个童年时期都会影响父母和后代的应激激素水平。
