Inroduction
The pandemic caused by the coronavirus disease-2019 (COVID-19) has caused millions of people’s death since December 2019 and continues to do so. Although an effective drug treatment has not yet been found, vaccines developed against COVID-19 have been applied all over the world since the last months of 2020. On the other hand, studies on which factors affect the severity of the disease are still continuing. Studies to date indicate that age is the primary risk factor for COVID-19-related hospitalization and/or death. In addition, it has been revealed that the clinical course of COVID-19 is more severe in patients with chronic diseases such as hypertension (HT), cardiovascular diseases (CVD), diabetes mellitus (DM), obesity, chronic kidney failure, and cancer [1–4].
The cellular structure and receptors of the severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) that causes COVID-19 was found in March 2020. It was determined that the virus entered the cell with the angiotensin converting enzyme-2 (ACE2) receptor and the transmembrane protease serine 2 (TMPRSS2) receptor facilitated the entry of the virus into the cell [5]. Since then, the use of drug groups such as ACE inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) [6–8], ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs) [9,10], thiazolidinediones [11] which may cause an increase or decrease in ACE2 expression, has been investigated in large-scale studies during the COVID-19 pandemic. In general, it has been demonstrated that these drugs do not affect the severity or mortality of COVID-19. Besides, studies in which metformin was associated with decreased mortality and insulin was associated with increased mortality were published [11–14]. Regarding dipeptidyl peptidase-4 (DPP4) inhibitors, results have been reported that they are associated with good or poor clinical course of COVID-19 [11,15,16].
Considering that the rate of spread of COVID-19 may be related to the expression status of ACE2 or TMPRSS2 receptors [17,18] or to some other genetic factors that are not yet known, data in different parts of the world are important. With this study, we aimed to examine the effects of previous drug utilization in the last 6 months before contracting COVID-19 on the clinical course of COVID-19 by presenting data from Istanbul, Turkey.