The annual survey of the Japanese Society for Dialysis Therapy Renal Data Registry (JRDR) was conducted for 4,493 dialysis facilities at the end of 2020 among which 4,437 facilities (98.8％) responded to the facility survey and 4,271 facilities (95.1％) responded to the patient survey. The number of chronic dialysis patients in Japan continues to increase every year； it has reached 347,671 at the end of 2020 and the prevalence ratio of dialysis patients was 2,754 per million population. The mean age of the prevalent dialysis patients in the patient survey was 69.4 years. Diabetic nephropathy was the most common primary disease of the prevalent dialysis patients (39.5％), followed by chronic glomerulonephritis (25.3％) and nephrosclerosis (12.1％). The number of incident dialysis patients during 2020 was 40,744； it decreased by 141from 2019. The average age was 70.88 years and diabetic nephropathy (40.7％) was the most common cause in incident dialysis patients. Nephrosclerosis became the second cause followed by glomerulonephritis. As 34,414 patients died in 2020, the crude annual mortality rate was 9.9％. The three major causes of death were heart failure (22.4％), infectious disease (21.5％) and malignancy (9.0％). The patients treated by hemodiafiltration (HDF) have been increasing in number rapidly since 2012. The number has reached 163,825 by the end of 2020, which accounted for 47.1％ of all dialysis patients. The number of peritoneal dialysis (PD) patients was 10,338 in 2020, which has slightly increased since 2017. The combination or hybrid therapy with hemodialysis (HD) or HDF was given to 20.8％ of PD patients. Home HD therapy was conducted in 751 patients at the end of 2020； it decreased by 9 from 2019. Clinical data about Coronavirus disease (COVID‒19) and malignant diseases were newly collected in 2020. The status of the past living kidney donor was also investigated as in 2019. Results obtained on each condition provide a fundamental information from which more clinically effective practice patterns on these conditions will be developed.

Secondary hyperparathyroidism (SHPT) is a major problem in chronic kidney disease (CKD), as it is associated with greater bone turnover and increased risks of fractures and cardiovascular mortality. The clinical use of calcimimetics, which improve the sensitivity of the calcium‒sensing receptor, has markedly facilitated the treatment of SHPT. However, here we report three hemodialysis‒dependent cases of hypercalcemia caused by the inappropriate use of the second‒generation calcimimetic etelcalcetide under low bone turnover. The serum calcium levels of a 38‒year‒old male, 62‒year‒old male, and 66‒year‒old female continued to increase to＞12 mg/dL in the presence of low serum intact parathyroid hormone levels (≤21 pg/mL), even after the discontinuation of oral or intravenous active vitamin D analogs. The patients’ serum calcium levels normalized about a month after the discontinuation of intravenous etelcalcetide. The administration of etelcalcetide under low bone turnover presumably caused adynamic bone disease and reduced the buffering capacity of calcium, resulting in hypercalcemia. Understanding the pathophysiology of bone disease and the appropriate use of calcimimetics are necessary in CKD patients.