Figure 4: Leptin in CKD: A Link between anemia, malnutrition, and SHPT.

SHPT, a common complication of CKD, manifests primarily as high circulating PTH levels, which can inhibit Akt activation and leptin production in adipose. Leptin regulates hematopoiesis and nutrition metabolism. In patients with severe SHPT, after PTX, adipocytes produced more leptin through up-regulated Akt signaling because of normalization with high PTH environment, which in turn increased circulating leptin levels, and finally improved anemia and malnutrition. SHPT, secondary hyperparathyroidism; PTH, parathyroid hormone.