Fig. 1

Apelin level in studied groups. Panel A indicates overall apelin level in COV patients compared to non-COV individuals. Analyzed by Mann–Whitney U test. Panel B indicates apelin level based on underlying diseases subgroups, analyzed by Kruskal–Wallis test followed by Mann–Whitney U test. @ P < 0.05 vs. non-COV, *P < 0.05, **P < 0.01, *** P < 0.001 vs. CTL and, #P < 0.05 vs. DM group. CTL control (healthy subjects), HTN hypertension, DM diabetes mellitus, OB obese. n = 15–20 in each group