In summary, the relationship between RBP4 and CKD involves multiple factors, including direct factors related to the breakdown and metabolism of RBP4 in the kidney and indirect factors related to the association of RBP4 with insulin resistance, diabetes, obesity, inflammation, hyperuricaemia, hypertension, and other risk factors of CKD. Here, RBP4 is linked to obesity due to melanocortin 4 receptor deficiency.