ALB and malnutrition: Besides, a reduced serum albumin level is a recognized clinical sign of malnutrition, and malnutrition causes respiratory muscle weakness and reduces pulmonary function (Kuzuya et al., 2007; Itoh et al., 2013; Rozga et al., 2013; Zhang et al., 2017; Arigliani et al., 2018; Eckart et al., 2020; Ferdous et al., 2021).