People with comorbidities, like cardiac and liver ailments, and smokers are more prone to fall prey to Covid-19, according to doctors.
The World Health Organisation (WHO) has listed smoking as one of the major risk factors for coronavirus as it suppresses immune functions of body.
Smokers have higher expression of ACE2 (angiotensin converting enzyme 2) that signals inflammation and also more secretory cells making them susceptible to infections, said Dr Latha Sharma, consultant pulmonologist, KIMS Hospitals.
ACE2, attached to the outer surface of cells in lungs, arteries, heart, kidney and intestines, also serves as the entry point for coronaviruse, including SARS-CoV-2 (Covid-19).
“Studies suggest Covid-19 virus interacts with specific human receptor, known as hACE2 (human angiotensin converting enzyme 2), that infects lungs and nasal mucosa. Hence, it’s highly recommended that one stays away from smoking to stay safe,” said Sharma.
According to a University College London study, smokers are 1.45 times more likely to have severe complications compared to non-smokers and those who quit smoking.
Also, critically ill Covid-19 patients with chronic obstructive pulmonary disease (COPD) had 63 per cent risk of severe disease and 60 per cent risk of mortality, while critically ill patients without COPD had only 33.4 per cent risk of severe disease and 55 per cent risk of mortality.
Dr Nishant Sinha, senior consultant pulmonologist, Continental Hospitals said while 60 plus years, diabetes and high blood pressure are seen as the likely comorbidities for a Covid-19 patient, a review of studies by public health experts convened by WHO, found that Covid-19 may turn more severe in smokers than on-smokers.
“Smoking impairs the capacity to fight infections due to damage of Cilia, tiny hair like structures in the airways. Tobacco smoke is also a major risk factor for non-communicable ailments, like cardiovascular and respiratory diseases, cancer and diabetes. Coronavirus infection turns severe in people with these ailments,” he said.