Cytokine concentrations after heavy alcohol consumption in people with and without a hangover

Purpose: After an evening of heavy alcohol consumption, next day alcohol hangovers are commonly experienced. However, about 20 to 25% of the people claim not to have a hangover, despite heavy alcohol consumption [1]. It has been suggested that not experiencing alcohol hangovers may increase the risk of continuing harmful drinking behavior. Therefore, further research on this topic is warranted. Although the causes of alcohol hangovers are unknown, it has been suggested that the immune system might play a role [2]. Previous research has found significant increases in IL-10, IL-12, and IFN-γ concentrations in during the hangover state [3]. Whereas these findings were observed in blood, the aim of the current study was to investigate cytokines levels in saliva and urine, determined after an evening of alcohol consumption in people who report a hangover compared to people who do not report a hangover (hangover resistant). Methods: N= 36 healthy subjects (22 female, 14 male), aged 18 to 35 years old, participated in this naturalistic study. N= 17 reported being hangover resistant and N= 19 reported having hangovers after heavy alcohol consumption. Of both groups, saliva and urine samples were collected on a control day (no alcohol consumed) and approximately 9 hours after stopping alcohol consumption on a hangover day (the day after an evening consuming alcohol). Cytokine concentrations (IL-1b, IL-2, IL-4, IL-5, IL-6, IL-10, GM-CSF, IFN-γ and TNF-α) on the hangover and control day were determined using Multiplex Bead Immuno-essays (Invitrogen by Life Technologies, California, USA) according to manufacturer's instructions. Difference scores (hangover - placebo) of cytokine concentrations were compared between subjects with a hangover and the hangover resistant group. Results: On average, participants consumed 11.6 (4.6) alcoholic drinks in the alcohol condition (hangover resistant group: 11.0 (4.6) drinks, hangover group: 12.1 (7.2) drinks. The difference in total alcohol consumed was not significant (p = 0.61). In saliva, significant increases in IL-2, IL-4, IL-5, IL-6, IL-10, IFN-γ and TNF-α concentrations were found in the hangover condition. In urine, significant increases were found for Il-4 and IL-6 in the hangover condition, whereas a significant decrease was found for IL-8. No significant differences were found between subjects with a hangover and hangover resistant subjects. Cytokine levels in urine were less pronounced when compared to those determined in saliva samples. Conclusions: Our results are consistent with previous research, showing significant increases in cytokine concentrations during alcohol hangover. The results were consistent in both saliva and urine samples, although the observed effects in saliva were more clear. No significant differences were found between subjects with a hangover and hangover resistant subjects. Further research should investigate the role of the immune system in the pathogenesis of alcohol hangover, and why some drinkers claim to be hangover resistant despite heavy alcohol consumption.