INCREASED FREE CORTISOL SECRETION AFTER AWAKENING IN CHRONICALLY STRESSED INDIVIDUALS DUE TO WORK OVERLOAD

The present study investigated the association between chronic stress and cortisol changes during the first hour after awakening in the morn ing. According to results of a pilot study, it was hypothesized that c hronically stressed subjects would show a more enhanced and prolonged increase of cortisol level after awakening compared to non-stressed su bjects. In 100 subjects, chronic stress was assessed twice with a I-we ek interval between measures and cortisol was repeatedly measured duri ng the first hour of awakening on 3 consecutive days. Results showed t hat chronically stressed subjects had a significantly larger increase in cortisol (+15.5 nmol/l) compared to unstressed subjects (+9.1 nmol/ l). Further analysis indicated a significant sex difference with large r increases in chronically stressed women (+16.5 nmol/l) compared to s tressed men (+11.8 nmol/l). From these data we conclude that a repeate d measurement of free cortisol in response to awakening should be cons idered a possible biological correlate of chronic stress. Possible cau ses, consequences and clinical relevance of this hypercortisolism in c hronically stressed subjects are briefly discussed. (C) 1998 John Wile y & Sons, Ltd.