title: Hypothalamo-pituitary adrenal axis and sympatho-adrenal medullary system responses to psychological stress were not attenuated in women with elevated physical fitness levels.
abstract: It is not clear if higher levels of cardiorespiratory fitness are associated with lower hypothalamo-pituitary adrenal (HPA) axis and sympatho-adrenal medullary (SAM) system reactivity to psychological stress in women. The association between cardio-metabolic risk markers and acute physiological responses to psychological stress in women who differ in their cardiorespiratory fitness status has also not been investigated. Women with high (n = 22) and low (n = 22) levels of fitness aged 30-50 years (in the mid-follicular phase of the menstrual cycle) were subjected to a Trier Social Stress Test (TSST) at 1500 h. Plasma concentrations of cortisol, adrenaline (Adr), noradrenaline (NA), and dopamine (DA) were measured in samples collected every 7-15 min from 1400 to 1700 h. Heart rate and blood pressure were measured at the same time points. Low-fit women had elevated serum triglyceride, cholesterol/HDL ratio, fasting glucose, and HOMA-IR levels compared with high-fit women. While cortisol, Adr, NA, HR, and blood pressure all demonstrated a significant response to the TSST, the responses of these variables did not differ significantly between high- and low-fit women in response to the TSST. Dopamine reactivity was significantly higher in the low-fit women compared with high-fit women. There was also a significant negative correlation between VO2 max and DA reactivity. These findings suggest that, for low-fit women aged 30-50 years, the response of HPA axis and SAM system to a potent acute psychological stressor is not compromised compared to that in high-fit women.
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, VIC, Australia.
authors.forename: Sisitha U
authors.initials: SU
authors.lastname: Jayasinghe
authors.affiliation: Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia.|Central Clinical School, Monash University, Melbourne, VIC, Australia.
authors.forename: Gavin W
authors.initials: GW
authors.lastname: Lambert
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, VIC, Australia.
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Torres
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, VIC, Australia.
authors.forename: Steve F
authors.initials: SF
authors.lastname: Fraser
authors.affiliation: Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia.
authors.forename: Nina
authors.initials: N
authors.lastname: Eikelis
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, VIC, Australia. anne.turner@deakin.edu.au.
authors.forename: Anne I
authors.initials: AI
authors.lastname: Turner
mesh_terms: D000313:Adrenal Medulla / Q000503:physiopathology*; D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D004298:Dopamine / Q000097:blood; D004837:Epinephrine / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D008055:Lipids / Q000097:blood; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D010809:Physical Fitness / Q000502:physiology* / Q000523:psychology; D010913:Pituitary-Adrenal System / Q000503:physiopathology*; D013315:Stress, Psychological / Q000097:blood / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*
chemical_list: D008055:Lipids; D004298:Dopamine; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine
keywords: Fitness; Stress; TSST; Women