In children with CKD who did not receive ESA, anemia was associated with older age (OR 1.075, p < 0.001), low weight (OR 0.853, p = 0.008), low body mass index (BMI) z-score (OR 0.779, p = 0.003), existence of glomerulonephritis (OR 3.263, p < 0.001), high levels of ionized parathyroid hormone (iPTH) (OR 1.007, p < 0.001) and serum phosphorus (OR 1.773, p < 0.001), low serum albumin (OR 0.498, p < 0.001) and calcium (OR 0.494, p < 0.001) levels, and low eGFR (OR 0.966, p < 0.001) in the univariate logistic regression. The gene discussed is PTH; the disease is chronic kidney disease.