Adrenaline during mental stress in relation to fitness, metabolic risk factors and cardiovascular responses in young men.

We studied plasma adrenaline ( A) in relation to physical fitness, metabolic cardiovascular risk factors and cardiovascular responses. Men ( age 21-24 years) with high and normal ( both n=519) screening blood pressure ( BP) were studied cross-sectionally. We measured peak oxygen uptake ( VO2peak) ( treadmill exercise), and plasma catecholamines, heart rate ( HR), finger systolic ( SBP) and diastolic ( DBP) BP, and insulin-adjusted glucose disposal rate ( GDR/I) during a hyperinsulinaemic glucose clamp ( rest) and mental arithmetic stress test ( MST). By multiple regression, A at rest ( A(rest)) ( beta 50.37, p < 0.05) and during MST ( A(mst)) ( beta 50.40, p < 0.01) were associated with high screening BP. In the respective models, Arest was negatively related to body mass index ( BMI) ( beta 520.56, p < 0.001) and A(mst) positively to VO2peak ( beta 50.54, p < 0.001). BP and HR responses correlated positively with VO2peak, but were determined by A(mst) in multiple regression models. Independently of BMI and VO2peak, serum high-density lipoprotein cholesterol was positively related to A levels, whereas GDR/I was independently related only to VO2peak. Increased adrenaline secretion may be related to high BP, but may at the same time be associated with a beneficial metabolic profile.