ALB and Pleural effusion: Patients with pleural effusion had significantly lower GFR (54.40 ± 20.21 vs. 62.29 ± 17.25 mL/min; p < 0.001) and albumin levels (33.94 ± 5.01 vs. 36.76 ± 6.52 g/dL; p = 0.037).