Bibian van der Voorn

173 GENDER-SPECIFIC HPA AXIS REACTIVITY IN CHILDHOOD TABLE 1. Summary of articles describing sex differences in diurnal rhythmicity Author (year) Sample size Age Sampling points Medium Results Adam (2010) 26 230 17.04±0.36 yrs 6x/day on 3 days Saliva Lower diurnal cortisol curves in boys Bae (2015) 36 138 (70 controls) 10.7±1.7 yrs 3x/day on 3 days Saliva Higher levels at awakening, 30 minutes after awakening and higher total daily output in girls; levels in the evening and diurnal slope: no sex differences Barbosa (2012) 22 145 8-10yr group: 9.0±0.8 yrs; 11-14yr group: 11.9±1.0 yrs 2x Saliva No sex differences, higher diurnal decline in children aged 11-14 yrs old Bartels (2003) 23 360 12 yrs 4x/day on 2 days Saliva No sex differences; pubertal status not assessed Carrion (2002) 24 31 Mean: 10.9 yrs 4x/day on 3 days Saliva No sex differences; pubertal status not associated with reactivity Doom (2013) 25 110 9.42±0.88 yrs 3x/day on 5 days Saliva No sex differences; pubertal status not assessed Fransson (2014) 31 157 14-16 yrs 4x (including CAR) Saliva Steeper decline in girls Garcia (1990) 12 76 (21 controls) 11.2±0.37 yrs 3-hourly during 24 hours Blood No sex differences; pubertal status not assessed Haen (1984) 11 64 1 mo. to 15 yrs 6 hourly (4x) Blood No sex differences; pubertal status not assessed Jones (2006) 14 140 7-9 yrs 5x Saliva No sex differences; pubertal status not assessed Kelly (2008) 32 2995 15.4±0.32 yrs 2x, 30min apart in the morning Saliva Steeper decline in girls Kjolhede (2014) 19 342 9.5±1.9 yrs 3x/day on 4 days Saliva No sex differences; pubertal status not assessed Knutsson (1997) 13 235 2.2-18.5 yrs 7x Blood No sex differences, except for higher values in girls at pubertal stage 2 Kuhlman (2015) 38 121 12.8±2.3 yrs 4x/day on 2 days Saliva No impact of sex on cortisol at awakening or linear decline, but boys showed less deceleration of the diurnal decline between dinner and bed-time. Lumeng (2014) 20 331 3-4 yrs 3x/day on 3 days Saliva No sex differences; pubertal status not assessed Martikainen (2013) 29 252 8.1±0.3 yrs 7x Saliva Higher morning cortisol in girls, no sex difference in nadir Matchock (2007) 39 120 Boys: 9, 11 or 13 yrs; girls: 8, 10 or 12 yrs 6x (including CAR) Saliva Cortisol peak occurred later in boys than girls during later puberty. Higher morning cortisol in boys at pubertal stage 2. AUCg: no effect of sex, but significant pubertal stage effect Michels (2012) 18 385 5-10 yrs 4x (including CAR) Saliva No sex differences except somewhat steeper decline in girls (p=0.30) Morin-Major (2016) 28 88 14.5±1.8 yrs 4x/day on 2 days Saliva Higher AUC in girls Netherton (2004) 37 129 12.8±0.19 yrs 2x/day on 4 days Saliva Mid-post pubertal girls higher morning cortisol than boys. No sex differences in variance across the four days Osika (2007) 15 84 9.9±0.55 yrs 5x (including CAR) Saliva No sex differences; pubertal status not assessed Rosmalen (2005) 30 1768 11.08±0.55 yrs 3x (including CAR) Saliva Higher morning cortisol levels in girls, no sex differences in evening cortisol, already present in pre-pubertal children. Age or pubertal status not associated with cortisol levels. Ruttle (2013) 33 346 11, 13 and 15 yrs 3x/day on 3 days Saliva Steeper slope in girls at ages 11 and 13, and in longitudinal analyses; higher cortisol levels in girls throughout the day at age 15 Shirtcliff (2012) 34 357 9, 11, 13 and 15 yrs 3x/day on 3 days Saliva Steeper slopes, more curvature in girls. Advancement through puberty: rhythm becomes flatter, especially in girls Susman (2007) 16 111 Boys: 9, 11 or 13 yrs; girls: 8, 10 or 12 yrs 6x (including CAR) Saliva No sex differences; pubertal status not associated with reactivity Tzortzi (2009) 17 21 10-14 yrs 20x (including CAR) Saliva No sex differences; pubertal status not assessed Vaillancourt (2008) 35 154 147±9.07 mo. 2x/day on 3 days Saliva Higher morning levels in girls on Saturday, multilevel regression: consistently higher production in girls Vanaelst (2013) 21 355 5-10 yrs 4x/day on 2 days (including CAR) Saliva No sex differences; pubertal status not assessed Williams (2013) 27 27 9.13±1.41 yrs 3x/day on 2 days (including CAR) Saliva Boys exhibited flatter slopes than girls