Bibian van der Voorn

179 GENDER-SPECIFIC HPA AXIS REACTIVITY IN CHILDHOOD not present in subjects aged 13-20 years. A similar result was found by Hostinar et al. (2015) 57 (n=81, age: 9.97±0.52 (children) and 16.05±0.39 (adolescents) years), who found a stronger cortisol response in girls at age 9-10, and no sex differences among the adolescents. Gunnar et al. (2009) 58 (n=82, age: 9, 11, 13 and 15 years) found a significantly higher AUCi in girls in response to the TSST-C at age 13, while no sex differences were found at ages 9, 11 and 15 years. Mrug et al. (2016) 59 (n=84, age: 13.4±1.0 years) found a higher cortisol 55 minutes post-test as well as a greater AUCi in girls. On the other hand, Lu et al. (2014) 60 (n=87, age: 12.7±0.3 years) found a significantly more negative logAUCi in girls, indicative of a smaller increase in cortisol in girls compared to boys after the TSST-C, and Trickett et al. (2014) 61 (n=151 controls, age 11.11±1.15 years) found a blunted cortisol response in girls compared to boys. Additionally, Bouma et al. (2009) 41 (n=644, age 16.1±0.6 years), who used the GSST, found lower cortisol responses in girls compared to boys, which was further specified in a study published by Bouma et al. in 2011 46 (n=553, age: 16.07±0.90 years), who found lower cortisol levels in girls on the first sample after completing the GSST. PHARMACOLOGICAL STRESS TESTS Seven studies (with the data of 322 subjects) investigated cortisol responses to pharmacological ACTH or CRH. Five studies (3 with ACTH, 2 with CRH) did not find significant sex differences, 62-66 and two studies found a smaller cortisol increase in girls. Stroud et al. (2011) 67 (n=68, age: 11.9±1.9 years), who performed a CRH challenge with 1μg/kg human CRH, found a smaller increase from baseline in girls compared to boys for all Tanner pubertal stages. Additionally, sex-specific pubertal changes were observed, with a baseline cortisol that increased in girls and decreased in boys with advancing puberty. Moreover, girls showed decreases in reactivity/ recovery rates (in μg/dL/min), as well as increases in total cortisol response (AUCg) and time to peak cortisol levels with pubertal maturation. Boys, on the other hand, showed little change in reactivity/recovery rates and no changes across puberty for the other parameters. Dahl et al. (1992) 68 (n=25, age: 10.3±1.6 years) also performed a 1μg/kg human CRH challenge, and found a smaller increase in cortisol concentration in girls compared to boys. MISCELLANEOUS STRESS TESTS Twenty-five studies (with the data of 3,004 subjects) performed a wide range of other stress tests. Three studies were performed in infants aged <1 year (with the data of 285 subjects), 69-71 of which two found a lower cortisol reactivity in girls: Davis and Emory