A review on association between respiratory infections and diabetes

Abstract

Respiratory disease is a major cause of elevated morbidity and mortality worldwide. Between 1990 and 2017, the mortality rate from chronic respiratory diseases increased by 18%, from 3.32 million to 3.91 million. Several studies have reported that people with diabetes have a significant rate of respiratory infection. This review evaluated the association between diabetes and multiple respiratory diseases such as Tuberculosis, Influenza, and Covid-19. Diabetes patients are often immunocompromised. Their health deteriorates further as they are exposed to respiratory infections, which result in serious health problems such as coronary complications, hyperglycemia, pulmonary vascular abnormality, renal impairment, pancreatitis, endothelial dysfunction, and inflammatory infiltration. In the case of tuberculosis, diabetes patients experience more disease complications than non-diabetics. Tuberculosis can result in infection-related hypoglycemia and hyperglycemia in diabetic patients, altering the immune response to tuberculosis, which causes further hypoglycemia and hyperglycemia-related complications. Moreover, diabetes patients show a less positive response to tuberculosis therapy. Due to influenza, diabetes patients become more vulnerable to a lung infection that might cause damage to myocardial tissues, ultimately resulting in cardiovascular complexity. So far, the evidence does not support that the SARS-CoV-2 infection rate is higher in diabetic patients. However, increased severity of SARS-CoV-2 infection is observed in diabetic patients. Increased viral entry, higher inflammation levels, and reduced T cell function have also been reported in SARS-CoV-2 infected diabetic patients.