title: Physical activity and hypothalamic-pituitary-adrenocortical axis function in adolescents.
abstract: Little is known about the associations between physical activity (PA) and hypothalamic-pituitary-adrenocortical axis (HPAA) activity in adolescents. This knowledge could offer insight into the links between PA and well-being in youth. We studied whether objectively-measured PA is associated with diurnal salivary cortisol responses and morning salivary cortisol responses after a low-dose overnight dexamethasone suppression test (DST) in adolescent girls and boys. We conducted a cross-sectional birth cohort study in Helsinki, Finland. At a mean age of 12.4 (SD=0.5) years, 150 girls and 133 boys wore wrist-worn accelerometers over at least 4 days to measure PA. Their salivary cortisol was measured across 1 day and upon awakening after a low-dose overnight DST (3 μg/kg of weight). Girls with higher overall PA and vigorous PA (VPA), and less sedentary time had lower salivary cortisol upon awakening and/or after (decreases between |0.17| and |0.25| SDs per SD increase in overall PA, VPA and decrease in sedentary time; P-values<0.039). Boys with higher overall PA, and less sedentary time had greater suppression of salivary cortisol following overnight DST (suppression between |0.24| and |0.27| SDs per SD increase in overall PA and decrease in sedentary time; P-values<0.012). Overall PA, VPA and sedentary time did not associate with DST suppression in girls or with diurnal salivary cortisol in boys. These results show that PA is associated with altered HPAA function in early adolescents, and that the associations are sex specific.
authors: Institute of Behavioural Sciences, University of Helsinki, Finland.
authors: Silja
authors: S
authors: Martikainen
authors: Institute of Behavioural Sciences, University of Helsinki, Finland.
authors: Anu-Katriina
authors: AK
authors: Pesonen
authors: Institute of Behavioural Sciences, University of Helsinki, Finland; Folkhälsan Research Center, Helsinki, Finland.
authors: Jari
authors: J
authors: Lahti
authors: Institute of Behavioural Sciences, University of Helsinki, Finland.
authors: Kati
authors: K
authors: Heinonen
authors: Institute of Behavioural Sciences, University of Helsinki, Finland.
authors: Riikka
authors: R
authors: Pyhälä
authors: Research Center for Sport and Health Sciences, Foundation for Sport and Health Sciences, Jyväskylä, Finland.
authors: Tuija
authors: T
authors: Tammelin
authors: Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland; Hospital for Children and Adolescents, Helsinki University Central Hospital and University of Helsinki, Finland; Department of Obstetrics and Gynaecology, MRC Oulu, Oulu University Central Hospital and University of Oulu, Oulu, Finland.
authors: Eero
authors: E
authors: Kajantie
authors: Department of Medicine, University of Helsinki, and Helsinki University Hospital, Helsinki, Finland; Institute of Health Sciences/Geriatrics, University of Oulu, Oulu, Finland.
authors: Timo E
authors: TE
authors: Strandberg
authors: Endocrinology Unit, University/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, Edinburgh, UK.
authors: Rebecca M
authors: RM
authors: Reynolds
authors: Institute of Behavioural Sciences, University of Helsinki, Finland. Electronic address: katri.raikkonen@helsinki.fi.
authors: Katri
authors: K
authors: Räikkönen
mesh_terms: D061725:Accelerometry; D000293:Adolescent; D000294:Adolescent Behavior / Q000502:physiology*; D015415:Biomarkers / Q000378:metabolism; D002648:Child; D002940:Circadian Rhythm / Q000502:physiology; D003430:Cross-Sectional Studies; D003907:Dexamethasone; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D010912:Pituitary-Adrenal Function Tests; D010913:Pituitary-Adrenal System / Q000378:metabolism*; D012463:Saliva / Q000378:metabolism; D012727:Sex Characteristics; D014851:Wakefulness
chemical_list: D015415:Biomarkers; D003907:Dexamethasone; D006854:Hydrocortisone
keywords: Actigraphy; Cortisol; Dexamethasone suppression test; Hypothalamic–pituitary–adrenocortical axis; Physical activity; Youth