Adrenocortical and gonadal steroids during sleep deprivation.

Twelve healthy males were exposed to 48 hr of sleep deprivation under conditions of strictly controlled activity and of food and drink intake. During the experiment the subjects were isolated from external time cures, i.e. no daylight, clocks, etc. Plasma samples were obtained before and at the end of the vigil, as well as after 5 days of recovery. Samples were analyzed for adrenal and gonadal steroid hormones and for follicle-stimulating (FSH) and luteinizing hormones (LH). The levels of all unconjugated steroids studied (cortisol, 17-hydroxypregnenolone, 17-hydroxyprogesterone, androstenedione, dihydrotestosterone) were significantly lower at the end of the sleep deprivation period. Self-ratings of fatigue were significantly higher at the end of the deprivation period. After recovery, all values returned to base line. No changes were observed in the levels of FSH, LH, or most conjugated steroids. It was concluded that the results were not consistent with the view that sleep deprivation induces an emergency reaction with increased activation, but rather that it results in lower levels of both psychological and physiological activation.