Prevalence of and Risk Factors Associated with Alcohol Overconsumption at 2 Years After Bariatric Surgery

Animal model for high consumption and preference of ethanol and its interplay with high sugar and butter diet, behavior, and neuroimmune system

Introduction

Mechanisms that dictate the preference for ethanol and its addiction are not only restricted to the central nervous system (CNS). An increasing body of evidence has suggested that abusive ethanol consumption directly affects the immune system, which in turn interacts with the CNS, triggering neuronal responses and changes, resulting in dependence on the drug. It is known that neuroinflammation and greater immune system reactivity are observed in behavioral disorders and that these can regulate gene transcription. However, there is little information about these findings of the transcriptional profile of reward system genes in high consumption and alcohol preference. In this regard, there is a belief that, in the striatum, an integrating region of the brain reward system, the interaction of the immune response and the transcriptional profile of the Lrrk2 gene that is associated with loss of control and addiction to ethanol may influence the alcohol consumption and preference. Given this information, this study aimed to assess whether problematic alcohol consumption affects the transcriptional profile of the Lrrk2 gene, neuroinflammation, and behavior and whether these changes are interconnected.

Methods

An animal model developed by our research group has been used in which male C57BL/6 mice and knockouts for the Il6 and Nfat genes were subjected to a protocol of high fat and sugar diet intake and free choice of ethanol in the following stages: Stage 1 (T1)—Dietary treatment, for 8 weeks, in which the animals receive high-calorie diet, High Sugar and Butter (HSB group), or standard diet, American Institute of Nutrition 93-Growth (AIN93G group); and Stage 2 (T2)—Ethanol consumption, in which the animals are submitted, for 4 weeks, to alcohol within the free choice paradigm, being each of them divided into 10 groups, four groups continued with the same diet and in the other six the HSB diet is substituted by the AIN93G diet. Five groups had access to only water, while the five others had a free choice between water and a 10% ethanol solution. The weight of the animals was evaluated weekly and the consumption of water and ethanol daily. At the end of the 12-week experiment, anxiety-like behavior was evaluated by the light/dark box test; compulsive-like behavior by Marble burying, transcriptional regulation of genes Lrrk2, Tlr4, Nfat, Drd1, Drd2, Il6, Il1β, Il10, and iNOS by RT-qPCR; and inflammatory markers by flow cytometry. Animals that the diet was replaced had an ethanol high preference and consumption.

Results and discussion

We observed that high consumption and preference for ethanol resulted in (1) elevation of inflammatory cells in the brain, (2) upregulation of genes associated with cytokines (Il6 and Il1β) and pro-inflammatory signals (iNOS and Nfat), downregulation of anti-inflammatory cytokine (Il10), dopamine receptor (Drd2), and the Lrrk2 gene in the striatum, and (3) behavioral changes such as decreased anxiety-like behavior, and increased compulsive-like behavior. Our findings suggest that interactions between the immune system, behavior, and transcriptional profile of the Lrrk2 gene influence the ethanol preferential and abusive consumption.

Utility of phosphatidylethanol testing as an objective measure of alcohol use during the preoperative evaluation for bariatric surgery

BACKGROUND

The risk of alcohol use disorder increases after bariatric surgery. Preoperative alcohol use is a risk factor, and this is evaluated during the routine preoperative psychosocial evaluation. However, it is not clear whether patients accurately report their alcohol use.

OBJECTIVE

To determine whether an objective measure of alcohol use, phosphatidylethanol (PEth) testing, offers utility beyond self-reported alcohol use during the preoperative evaluation for bariatric surgery.

SETTING

Single healthcare system.

METHODS

PEth testing was included as part of the routine laboratory work for 139 patients undergoing evaluation for bariatric surgery. PEth testing results were compared with self-reported alcohol use and scores on the Alcohol Use Disorders Identification Test-Concise (AUDIT-C) questionnaire obtained during the preoperative psychosocial evaluation. PEth testing results were categorized into abstinent, light use, moderate use, or heavy use. There were 85 patients who completed both PEth testing and a preoperative psychosocial evaluation.

RESULTS

There were 25 participants (29.4%) who had a positive PEth test; about half had moderate or heavy use values (15.3% of the total sample). The majority of participants with a positive PEth test (82.6%) denied recent alcohol use. Of those with PEth values indicating moderate or heavy use, 61.5% did not have an elevated AUDIT-C score.

CONCLUSIONS

Patients appeared to underreport their alcohol use during the preoperative psychosocial evaluation. There appears to be utility for routine PEth testing as part of the evaluation process to identify those with risky drinking patterns. Patients with preoperative risky drinking could be educated about their risk and/or referred to programs to mitigate the development of preoperative alcohol misuse.