Washington: Chronic alcohol misuse is an overlooked risk factor for developing severe COVID-19, according to a review of studies. The researchers at Rush University Medical Center, US, noted that research points to COVID-19 patients' contrasting immune responses as a key driver of symptom severity. Some people are known to be more vulnerable to severe COVID-19, including adults aged 65 and above and those with pre-existing health conditions, such as Type 2 diabetes, cardiovascular disease, chronic lung disease, and kidney disease.
However, many patients who experience severe COVID-19, sometimes including death, do not fit into these categories, implying that additional risk factors are involved. Studies have found that Alcohol Use Disorder (AUD) is associated with severe COVID-19 disease or higher risk of mortality, especially in the elderly.
Substance use disorders (SUDs) generally are linked to an increased risk of COVID-19 severity and of other underlying health conditions associated with worse COVID-19 outcomes, the researchers said. The research, published in the journal Alcoholism: Clinical & Experimental Research, evaluated data from studies relating to alcohol misuse, COVID-19 severity, and factors and mechanisms involved in worse outcomes.
In COVID-19, some patients’ immune systems fail to control the reproduction of the virus, leading to high viral levels. The resulting exaggerated inflammatory response - a “cytokine storm” - triggers acute respiratory distress syndrome (ARDS).
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This severe form of lung injury is the most common cause of death in COVID-19, according to the researchers. Increasing evidence implicates a certain inflammasome - a protein complex that induces inflammation to help clear the body of threats - called NLRP3. Scientists have identified mechanisms by which alcohol misuse may impair the immune response to pathogens, especially in the lungs, and contribute to dangerous inflammatory responses. Chronic alcohol use is almost uniformly associated with NLRP3 activation, the researchers said.
Studies of people with chronic alcohol exposure and COVID-19 patients reveal the same systemic inflammation pathways, including inflammasome activation and amplified cytokine release, they said. Studies point to a plausible biological process. This relates to the gastrointestinal (GI) tract, a battleground for COVID-19 possibly second only to the lungs. GI symptoms in COVID-19 are linked to worse outcomes. The intestinal microbiome - micro-organisms in the gut - and the immune system appear closely intertwined, according to the researchers.
Alcohol misuse and other underlying conditions that worsen COVID-19 share certain GI vulnerabilities: a pro-inflammatory microbiome in the gut and “leaky gut” - abnormal intestinal permeability, allowing microbes to move into the blood, they said. These two conditions combine to transfer gut bacteria to the lungs. That activates NLRP3, leading to systemic inflammation, manifesting as ARDS and more severe COVID-19, the researchers said. They concluded that severe COVID-19 including death is clearly associated with AUD and SUD. (PTI)
(This story has not been edited by ETV Bharat and is auto-generated from a syndicated feed.)
