Effects of Fasting and Glucose Load on Free Cortisol Responses to Stress and Nicotine1
The availability of energy appears to exert important regulatory functions in pituitary-adrenal stress responses. In two studies, the effects of short-term fasting and subsequent glucose administration on the free cortisol response to psychological stress and nicotine consumption were investigated. Study 1: After fasting for 8-11 h, healthy young men ingested either 100 g glucose (n = 13) or water (n = 12). One hour later they were exposed to a psychosocial stress task (Trier Social Stress Test). A third group also ingested 100 g glucose, but they were not exposed to any additional treatment (n = 10). Capillary blood glucose levels were in the lower euglycemic range before and significantly…
Glucose but Not Protein or Fat Load Amplifies the Cortisol Response to Psychosocial Stress
We previously reported that glucose intake amplifies cortisol response to psychosocial stress and smoking in healthy young men, while low blood glucose levels prevented the stress-induced activation of the hypothalamus pituitary adrenal (HPA) axis. However, it remains unknown whether this modulation is specific for glucose load or a more common effect of energy availability. To elucidate this question, 37 healthy men, who fasted for at least 8 h before the experiment, were randomly assigned to four experimental groups, who received glucose (n = 8), protein (n = 10), fat (n = 10), and water (n = 9), one h before their exposure to the Trier Social Stress Test (TSST). Blood glucose levels were…