The Potential Effect Of Leptin And Il-6 Levels On Covid-19 Severity In Obese Patients

Abstract

Background: The obesity is one of the high-risk factors in COVID-19 in severe illness and mortality as the pandemic progresses. The
pleotropic Leptin is a polypeptide hormone and secreted by adipose tissues. It acts as a proinflammatory cytokine. Leptin is associated
with severe conditions known to cause the risk of COVID-19 severity. Acute changes in calorie intake affect Leptin levels, which in
turn are related to the amount of adipose tissue. Interleukin 6 (IL-6) also is a pleiotropic cytokine (184 amino acid) and initiates different
inflammatory responses in tissues.
The aim of study: The aim of this study is to evaluate the effect of Leptin and IL-6 levels on the COVID-19 severity of an early
diagnosis in obese patients infected with COVID-19.
Materials and Methods: This case-control study included 60 obese subjects, divided to 30 obese without any chronic disease and not
infected with COVID-19, and 30 individuals were infected with COVID-19, with the age ranged between (25-60) years. COVID-19
patients divided into three categories, (13 mild/moderate), (10 severe) and (7 dead). And thirty (20 male and 10 female) apparently
healthy subjects as control group. Their age and sex were comparable to the patients. The enzyme-linked immunosorbent assay
(ELISA) kits used to measure serum Leptin and IL-6 levels.
Results: Leptin concentration and IL-6 concentration were significantly higher in obese COVID-19 patients than the obese without
COVID-19 and normal weight control group (11.80±1.38, 344.23±70.13 vs 8.64±1.21, 790.34±194.29 vs 4.09±2.15, 138.89±46.36)
respectively. However, especially in dead and severe cases increased levels of IL-6 and Leptin than the mild/moderate cases of obese
patients infected with COVID-19. Serum leptin level has a positive significant correlation with levels of IL-6, D-dimer, ferritin and
NLR in obese COVID-19 patients group.
Conclusions: High circulating IL-6 and Leptin in the obese patients might involve dysregulation of proinflammatory cytokines in
obesity and may be used as a useful prognostic tool associated with COVID-19 to predict the SARS-COV-2 severity.