These trends are consistent with Abdelnabi et al. (2021), who observed significantly lower Hb in patients with CKD (10 g/dL) compared to controls (12.4 g/dL), while Behera (2020) [21] noted a mean Hb of 7.76 g/dL in CKD cases versus 13.2 g/dL in controls [18,21]. This evidence concerns the gene GSTM1 and chronic kidney disease.