Salivary or serum cortisol: possible implications for alcohol research

The aim of this study was to clarify the effect of alcohol on cortisol prior to a meal by contrasting the effect of consuming a small-moderate amount of white wine on salivary cortisol and serum cortisol when sampled simultaneously, with salivary cortisol when sampled alone in fasted individuals. A total of 16 males aged 19-22 years participated in the investigation. The experimental procedure required all participants to fast for six hours and then ingest 40g alcohol in the form of white wine over a 135-min period. Participants were separated into two groups (serum+saliva, saliva only). In the saliva (only) trial (n=8) the level of blood alcohol and salivary cortisol was assessed upon arrival (0-min) and then again at 45-min, 90-min and 135-min.Similarly, in the serum+saliva trial (n=8) the level of blood alcohol, serum cortisol and salivary cortisol was assessed at regular intervals across the 135-min alcohol consumption period but serum cortisol and salivary cortisol was sampled simultaneously. The results showed that when white wine is consumed prior to food the level of: serum cortisol is significantly increased immediately; salivary cortisol is not significantly altered when measured during blood sampling; salivary cortisol is significantly decreased when measured in the absence of blood sampling. It was concluded that when assessing the effects of alcohol on the hypothalamic-pituitary-adrenal axis care should be taken to ensure that the experimental methodology does not inadvertently influence the final results. Cortisol is rapidly released in response to stress and the stress of the blood sampling procedure is a significant factor that if not controlled for could potentially obscure the true effects of alcohol on the hypothalamic-pituitary-adrenal axis