Naoki Kimata

Bio: Naoki Kimata is an academic researcher. The author has contributed to research in topics: Hemodialysis & Dialysis. The author has an hindex of 23, co-authored 48 publications receiving 2903 citations.

An Overview of Regular Dialysis Treatment in Japan (As of 31 December 2013)

Abstract: A nationwide survey of 4325 dialysis facilities was conducted at the end of 2013, among which 4268 (98.7%) responded. The number of new dialysis patients was 38,095 in 2013. Since 2008, the number of new dialysis patients has remained almost the same without any marked increase or decrease. The number of dialysis patients who died in 2013 was 30,751. The dialysis patient population has been growing every year in Japan; it was 314,438 at the end of 2013. The number of dialysis patients per million at the end of 2013 was 2470. The crude death rate of dialysis patients in 2013 was 9.8%. The mean age of new dialysis patients was 68.7 years and the mean age of the entire dialysis patient population was 67.2 years. The most common primary cause of renal failure among new dialysis patients was diabetic nephropathy (43.8%). The actual number of new dialysis patients with diabetic nephropathy has almost been unchanged for the last few years. Diabetic nephropathy was also the most common primary disease among the entire dialysis patient population (37.6%), followed by chronic glomerulonephritis (32.4%). The percentage of dialysis patients with diabetic nephropathy has been increasing continuously, whereas the percentage of dialysis patients with chronic glomerulonephritis has been decreasing. The number of patients who underwent hemodiafiltration (HDF) at the end of 2013 was 31,371, a marked increase from that in 2012. This number is more than twice that at the end of 2011 and approximately 1.5 times the number at the end of 2012. In particular, the number of patients who underwent online HDF increased approximately fivefold over the last 2 years. Among 151,426 dialysis patients with primary causes of renal failure other than diabetic nephropathy, 10.8% had a history of diabetes. Among those with a history of diabetes, 26.8% used glycoalbumin as an indicator of blood glucose level; and 33.0 and 27.6% were administered insulin and dipeptidyl peptidase (DPP)-4 inhibitor, respectively, as a medication of diabetes. The facility survey showed that 9392 patients underwent peritoneal dialysis (PD). The patient survey revealed that 1920 of these PD patients also underwent another dialysis method using extracorporeal circulation, such as hemodialysis (HD) or HDF. The number of patients who underwent HD at home at the end of 2013 was 461, a marked increase from that at the end of 2012 (393).

Overview of Regular Dialysis Treatment in Japan (as of 31 December 2011)

Abstract: A nationwide statistical survey of 4255 dialysis facilities was conducted at the end of 2011. Responses were submitted by 4213 facilities (99.0%). The number of new patients started on dialysis was 38,613 in 2011. Although the number of new patients decreased in 2009 and 2010, it increased in 2011. The number of patients who died each year has been increasing; it was 30,743 in 2011, which exceeded 30,000 for the first time. The number of patients undergoing dialysis has also been increasing every year; it was 304,856 at the end of 2011, which exceeded 300,000 for the first time. The number of dialysis patients per million at the end of 2011 was 2385.4. The crude death rate of dialysis patients in 2011 was 10.2%, which exceeded 10% for the first time in the last 20 years. The mean age of new dialysis patients was 67.84 years and the mean age of the entire dialysis patient population was 66.55 years. The most common primary cause of renal failure among new dialysis patients was diabetic nephropathy (44.3%). Diabetic nephropathy was also the most common primary disease among the entire dialysis patient population (36.7%), exceeding chronic glomerulonephritis (34.8%) which had been the highest until last year. The survey included questions related to the Great East Japan Earthquake, which occurred on 11 March 2011. The results on items associated with the Great East Japan Earthquake were reported separately from this report. The mean uric acid levels of the male and female patients were 7.30 and 7.19 mg/dL, respectively. Certain drugs for hyperuricemia were prescribed for approximately 17% of patients. From the results of the facility survey, the number of patients who underwent peritoneal dialysis (PD) was 9642 and the number of patients who did not undergo PD despite having a peritoneal dialysis catheter was 369. A basic summary of the results on the survey items associated with PD is included in this report and the details were reported separately.

Overview of regular dialysis treatment in Japan (as of 31 December 2008).

Abstract: A nationwide statistical survey of 4124 dialysis facilities was conducted at the end of 2008 and 4081 facilities (99.0%) responded. The number of patients undergoing dialysis at the end of 2008 was determined to be 283,421, an increase of 8179 patients (3.0%) compared with that at the end of 2007. The number of dialysis patients per million at the end of 2008 was 2220. The crude death rate of dialysis patients from the end of 2007 to the end of 2008 was 9.8%. The mean age of the new patients begun on dialysis was 67.2 years and the mean age of the entire dialysis patient population was 65.3 years. For the primary diseases of the new patients begun on dialysis, the percentages of patients with diabetic nephropathy and chronic glomerulonephritis were 43.3% and 22.8%, respectively. Among the facilities that measured bacterial count in the dialysate solution in 2008, 52.0% of facilities ensured that a minimum dialysate solution volume of 10 mL was sampled. Among the patients treated by facility dialysis, 95.4% of patients were treated three times a week, and the average time required for one treatment was 3.92 ± 0.53 (SD) h. The average amounts of blood flow and dialysate solution flow were 197 ± 31 and 487 ± 33 mL/min, respectively. The number of patients using a polysulfone membrane dialyzer was the largest (50.7%) and the average membrane area was 1.63 ± 0.35 m(2). According to the classification of dialyzers by function, the number of patients using a type IV dialyzer was the largest (80.3%). The average concentrations of each electrolyte before treatment in patients treated with blood purification by extracorporeal circulation were 138.8 ± 3.3 mEq/L for serum sodium, 4.96 ± 0.81 mEq/L for serum potassium, 102.1 ± 3.1 mEq/L for serum chloride, and 20.7 ± 3.0 mEq/L for HCO(3) (-) ; the average serum pH was 7.35 ± 0.05. Regarding the type of vascular access in patients treated by facility dialysis, in 89.7% of patients an arteriovenous fistula was used and in 7.1% an arteriovenous graft was used. The percentage of hepatitis C virus (HCV)-positive patients who were HCV-negative in 2007 was 1.04%; the percentage is particularly high in patients with a period of dialysis of 20 years or longer. The risk of becoming HCV-positive was high in patients with low serum creatinine, serum albumin, and serum total cholesterol levels, and/or a low body mass index before beginning dialysis.

The Japanese Society of Hypertension Guidelines for the Management of Hypertension (JSH 2019)

Abstract: Satoshi Umemura ● Hisatomi Arima ● Shuji Arima ● Kei Asayama ● Yasuaki Dohi ● Yoshitaka Hirooka ● Takeshi Horio ● Satoshi Hoshide ● Shunya Ikeda ● Toshihiko Ishimitsu ● Masaaki Ito ● Sadayoshi Ito ● Yoshio Iwashima ● Hisashi Kai ● Kei Kamide ● Yoshihiko Kanno ● Naoki Kashihara ● Yuhei Kawano ● Toru Kikuchi ● Kazuo Kitamura ● Takanari Kitazono ● Katsuhiko Kohara ● Masataka Kudo ● Hiroo Kumagai ● Kiyoshi Matsumura ● Hideo Matsuura ● Katsuyuki Miura ● Masashi Mukoyama ● Satoko Nakamura ● Takayoshi Ohkubo ● Yusuke Ohya ● Takafumi Okura ● Hiromi Rakugi ● Shigeyuki Saitoh ● Hirotaka Shibata ● Tatsuo Shimosawa ● Hiromichi Suzuki ● Shori Takahashi ● Kouichi Tamura ● Hirofumi Tomiyama ● Takuya Tsuchihashi ● Shinichiro Ueda ● Yoshinari Uehara ● Hidenori Urata ● Nobuhito Hirawa

Serum Levels of Phosphorus, Parathyroid Hormone, and Calcium and Risks of Death and Cardiovascular Disease in Individuals With Chronic Kidney Disease: A Systematic Review and Meta-analysis

Abstract: Context Clinical practice guidelines on the management of mineral and bone disorders due to chronic kidney disease recommend specific treatment target levels for serum phosphorus, parathyroid hormone, and calcium. Objective To assess the quality of evidence for the association between levels of serum phosphorus, parathyroid hormone, and calcium and risks of death, cardiovascular mortality, and nonfatal cardiovascular events in individuals with chronic kidney disease. Data Sources The databases of MEDLINE (1948 to December 2010) and EMBASE (1947 to December 2010) were searched without language restriction. Hand searches also were conducted of the reference lists of primary studies, review articles, and clinical guidelines along with full-text review of any citation that appeared relevant. Study Selection Of 8380 citations identified in the original search, 47 cohort studies (N = 327 644 patients) met the inclusion criteria. Data Extraction The characteristics of study design, participants, exposures, and covariates together with the outcomes of all-cause mortality, cardiovascular mortality, and nonfatal cardiovascular events at different levels of serum phosphorus, parathyroid hormone, and calcium were analyzed within studies. Data were summarized across studies (when possible) using random-effects meta-regression. Data Synthesis The risk of death increased 18% for every 1-mg/dL increase in serum phosphorus (relative risk [RR], 1.18 [95% confidence interval {CI}, 1.12-1.25]). There was no significant association between all-cause mortality and serum level of parathyroid hormone (RR per 100-pg/mL increase, 1.01 [95% CI, 1.00-1.02]) or serum level of calcium (RR per 1-mg/dL increase, 1.08 [95% CI, 1.00-1.16]). Data for the association between serum level of phosphorus, parathyroid hormone, and calcium and cardiovascular death were each available in only 1 adequately adjusted cohort study. Lack of adjustment for confounding variables was not a major limitation of the available studies. Conclusions The evidentiary basis for a strong, consistent, and independent association between serum levels of calcium and parathyroid hormone and the risk of death and cardiovascular events in chronic kidney disease is poor. There appears to be an association between higher serum levels of phosphorus and mortality in this population.

The mortality risk of overhydration in haemodialysis patients

Abstract: Background. While cardiovascular events remain the primary form of mortality in haemodialysis (HD) patients, few centres are aware of the impact of the hydration status (HS). The aim of this study was to investigate how the magnitude of the prevailing overhydration influences long-term survival. Methods. We measured the hydration status in 269 prevalent HD patients (28% diabetics, dialysis vintage = 41.2 ± 70 months) in three European centres with a body composition monitor (BCM) that enables quantitative assessment of hydration status and body composition. The survival of these patients was ascertained after a follow-up period of 3.5 years. The cut off threshold for the definition of hyperhydration was set to 15% relative to the extracellular water (ECW), which represents an excess of ECW of ∼2.5 l. Cox-proportional hazard models were used to compare survival according to the baseline hydration status for a set of demographic data, comorbid conditions and other predictors. Results. The median hydration state (HS) before the HD treatment (� HSpre) for all patients was 8.6 ± 8.9%. The unadjusted gross annual mortality of all patients was 8.5%.