Chronic Kidney Disease In Japan Research Articles

Regional variance in patterns of prescriptions for chronic kidney disease in Japan.

This study aims to describe the regional variance in prescriptions for chronic kidney disease (CKD) medications and to analyze regional characteristics to identify the sources of these differences by utilizing the National Database of Health Insurance Claims, which provides more than 95% of nationwide claim information for Japan. Data regarding the total claimed amount for phosphate binders (PBs), erythropoiesis-stimulating agents (ESAs), carbonaceous adsorbents, and potassium-lowering agents in fiscal year 2015 were obtained. Correlation coefficients were calculated for the claimed amount of these drugs per CKD patient and social and medical variables, including the percentage of the population aged ≥ 65years and the numbers of hospital beds and certified nephrologists. Subsequent multiple regression analysis was performed using explanatory factors affecting the amount of PB or ESA prescriptions per CKD patient. The total claimed amounts were 585,485,115 for PBs and 2,373,777 for ESAs. Variations in the claimed amount per CKD patient among 47 prefectures were 4.9-, 6.1-, 6.6-, and 6.0-fold for PBs, ESAs, carbonaceous adsorbents and potassium-lowering agents, respectively. The number of nephrologists per CKD patient was positively correlated with the prescribed amount for PBs and ESAs per CKD patient, and independently associated with the prescribed amount also in regression analysis. Substantial regional variation in CKD-related drug prescriptions exists even within a uniform health care system. The number of certified nephrologists was associated with the prescribed amount for PBs and ESAs. Further studies are needed to clarify whether geographic distribution of certified nephrologist may affect clinical practice pattern.

New insights on glomerular hyperfiltration: a Japanese autopsy study.

It has been suggested that low nephron number contributes to glomerular hypertension and hyperperfusion injury in progressive chronic kidney disease (CKD). The incidence of CKD in Japan is among the highest in the world, but the reasons remain unclear. We estimated total nephron (glomerular) number (NglomTOTAL) as well as numbers of nonsclerosed (NglomNSG) and globally sclerosed glomeruli (NglomGSG), and the mean volume of nonsclerosed glomeruli (VglomNSG) in Japanese normotensive, hypertensive, and CKD subjects and investigated associations between these parameters and estimated glomerular filtration rate (eGFR). Autopsy kidneys from age-matched Japanese men (9 normotensives, 9 hypertensives, 9 CKD) had nephron number and VglomNSG estimated using disector/fractionator stereology. Subject eGFR, single-nephron eGFR (SNeGFR), and the ratio SNeGFR/VglomNSG were calculated. NglomNSG in Japanese with hypertension (392,108 ± 87,605; P < 0.001) and CKD (268,043 ± 106,968; P < 0.001) was less than in normotensives (640,399 ± 160,016). eGFR was directly correlated with NglomNSG (r = 0.70, P < 0.001) and inversely correlated with VglomNSG (r = -0.53, P < 0.01). SNeGFR was higher in hypertensives than normotensives (P = 0.03), but was similar in normotensives and CKD, while the ratio SNeGFR/VglomNSG was similar in normotensives and hypertensives but markedly reduced in CKD. Nephron number in Japanese with hypertension or CKD was low. This results in a higher SNeGFR in hypertensives compared with normotensive and CKD subjects, but lowered SNeGFR/VglomNSG in CKD subjects, suggesting that changes in GFR are accommodated by glomerular hypertrophy rather than glomerular hypertension. These findings suggest glomerular hypertrophy is a dominant factor in maintenance of GFR under conditions of low nephron number.

PUK26 - Burden of Illness Associated With Anaemia In Chronic Kidney Disease In Japan: A Literature Review

PUK26 - Burden of Illness Associated With Anaemia In Chronic Kidney Disease In Japan: A Literature Review

A nationwide prospective cohort study of patients with advanced chronic kidney disease in Japan: The Reach-J CKD cohort study.

Epidemiology and outcomes of Japanese patients with advanced chronic kidney disease (CKD)-an estimated glomerular filtration rate (eGFR)<45ml/min/1.73m2-has remained largely unexamined. We conducted a nationwide survey to determine the distribution of Japanese CKD patients, and are conducting a cohort study of these patients. A questionnaire eliciting details about facilities and their CKD practices was sent to all clinics/hospitals with nephrologists. Based on the survey results, we recruited 2400 advanced CKD patients receiving nephrologist care from at least 30 representative facilities throughout Japan, selected randomly with stratification by region and facility size. Through patient questionnaires and nephrologist-practice surveys aligned with the international CKD Outcomes and Practice Patterns Study (CKDopps), we shall annually or semi-annually collect patient, physician and clinic data prospectively, detailing CKD practices for 5years, with a primary outcome of death or renal replacement therapy initiation, and secondary outcomes being decline of eGFR by 30% or 50%, CKD progression to CKD G5, or a cardiovascular event. Of 790 eligible, responding facilities, 330 (41.8%) treat ≥80 advanced CKD patients in the average 3-month period. Regional distribution of these facilities is similar to that of persons in the general population. Hence, the 30 facilities selected for data collection appear to be geographically representative in Japan. Our study will enhance understanding of various CKD practices and biological data associated with CKD progression, and allow international comparisons using the CKDopps platform. This will provide evidences to improve the health and quality of life for patients with advanced CKD.

Individual Income Status Correlates with Chronic Kidney Disease in Japan beyond Metabolic Risk Factors: Cross Sectional Study

Background: Chronic kidney disease (CKD) is a pre-condition for end-stage kidney disease (ESKD) undergoing hemodialysis, as well as a risk factor for cardiovascular disease. Therefore, it is vital that CKD prevention measures be established. In particular, socioeconomic status (SES), as represented by income, contributes to non-communicable diseases like CKD. The purpose of this study was to examine the independent association between CKD and individual SES in Japan, with consideration of other metabolic risks. Methods: In the present study, we analyzed the 2011 National Health and Nutrition Survey by the Ministry of Health, Labor, and Welfare. Specifically, we analyzed 3,557 people out of 8,762 whose serum creatinine was measured. Logistic regression analysis was used to calculate the odds ratio (OR) of CKD by income distinction, after adjustment for age and metabolic risks (obesity, diabetes mellitus, dyslipidemia, and hypertension), which were assessed at the medical examination. Results: CKD was found in 385 participants (10.8%) and was associated with greater age, obesity, higher levels of low-density lipoprotein cholesterol, triglyceride, and glycated hemoglobin, and lower levels of hemoglobin and high-density lipoprotein cholesterol. The adjusted model indicated a significant association between lower income and CKD: the OR of the low income group (<2 million yen) was 1.33 (95% confidence interval: 1.01 - 1.78) in comparison with the high income group. Conclusions: The results of the present study indicate a substantial relationship between individual lower income status and CKD in Japan, where healthcare is easy to access. To prevent ESKD and cardiovascular diseases, early detection of CKD and its metabolic risks is necessary, especially among the socioeconomically vulnerable population.

Association between low birth weight and childhood-onset chronic kidney disease in Japan: a combined analysis of a nationwide survey for paediatric chronic kidney disease and the National Vital Statistics Report.

Although numerous epidemiological surveys performed across several continents and ethnic groups have linked low birth weight (LBW) to increased risk of chronic kidney disease (CKD) in adulthood, the effects of birth weight and prematurity on development of CKD in childhood have not been clearly established. Data on sex, LBW incidence and gestational age were compared between paediatric CKD cases and a control group. Paediatric CKD cases were obtained from a nationwide survey conducted by the Pediatric CKD Study Group in Japan. The population attributable fraction was calculated to evaluate the effects of reducing the prevalence of LBW infants (LBWI). Of 447 individuals born between 1993 and 2010 that fulfilled the eligibility criteria, birth weight data were obtained for 381 (85.2%) (231 boys and 150 girls), 106 (27.8%) of whom were LBWI. The proportion of LBWI in the general population during the same period was much lower (8.6%). Therefore, the risk ratio (RR) for paediatric CKD was significantly higher in the LBW group [crude RR: 4.10; 95% confidence interval (CI) 3.62-5.01], and the overall impact on paediatric CKD for removal of LBW amounted to 21.1% (95% CI 16.0-26.1%). In addition, 82 patients (21.9%) with paediatric CKD were born prematurely (before 37 weeks of gestation), and as with LBW, a strong correlation was observed between prematurity and CKD (RR: 4.73; 95% CI 3.91-5.73). Both birth weight and gestational age were strongly associated with childhood-onset CKD in this study.

Anaemia management and mortality risk in newly visiting patients with chronic kidney disease in Japan: The CKD-ROUTE study.

To investigate the association between iron deficiency anaemia and mortality risk and assess the changes in anaemia and iron status after primary management by a nephrologist. In this prospective cohort study, we stratified 951 non-dialysis chronic kidney disease (CKD) G2-G5 patients newly visiting 16 nephrology centres into four groups according to the presence of anaemia with or without iron deficiency. All-cause mortality, cardiovascular (CV)-related mortality, and a change in anaemia and iron status after specialized primary care were the endpoints evaluated. During a median follow-up time of 19 months, the number of all-cause deaths and CV-related deaths were 56 and 26, respectively. Compared with the control group, the groups with isolated anaemia and iron deficiency anaemia had significantly higher all-cause mortalities (isolated anaemia: hazard ratio (HR), 3.37; 95% confidence intervals (CI), 1.76-6.44; iron deficiency anaemia: HR, 3.11; 95% CI, 1.21-8.01) and CV-related mortalities (isolated anaemia: HR, 3.64; 95% CI, 1.36-9.73; iron deficiency anaemia: HR, 3.86; 95% CI, 1.11-13.41). In the isolated anaemia group, erythropoietin-stimulating agent (ESA) prescriptions significantly increased to approximately 70%. However, in patients with both anaemia and iron deficiency, iron prescriptions only increased to 48.1%. Iron deficiency anaemia and isolated anaemia were associated with all-cause and CV-related mortality. The absence of relative increase in iron prescriptions suggests that iron deficiency should be accurately assessed and iron supplementation should be appropriately used to manage anaemia in non-dialysis patients with CKD.

Growth impairment in children with pre-dialysis chronic kidney disease in Japan.

Growth impairment is a major complication of chronic kidney disease (CKD) in children. However, no cohort studies have examined the growth of Asian children with pre-dialysis CKD. We sent cross-sectional surveys to 113 Japanese medical institutions that were treating 447 children with CKD stages 3-5 in 2010 and 2011. Of 447 children included in our survey conducted in 2010, height and CKD stage were evaluable for 297 children in 2011, and height standard deviation score (height SDS) was calculated in these children. Height SDS decreased with increasing CKD stage (P < 0.001) in boys and girls. Height SDS also decreased significantly with increasing CKD stage among patients with congenital anomalies of the kidney and urinary tract (P < 0.001). Risk factors for growth impairment included CKD stages 4 and 5 (relative to stage 3), being small-for-date, and asphyxia at birth. Among children with a height SDS ≤-2.0, growth hormone was used in 19.5, 31.0, and 25.0 % of children with CKD stages 3, 4, and 5, respectively. This prospective cohort study revealed marked growth impairment in Japanese children with CKD stages 3-5 relative to healthy children. CKD-related risk factors for growth impairment included advanced CKD (stages 4 and 5), being small-for-date, and asphyxia at birth. Growth hormone was infrequently used in this cohort of children with pre-dialysis CKD.

Niacin and Chronic Kidney Disease.

Chronic kidney disease (CKD) is an increasing problem worldwide. The number of end-stage renal disease patients requiring treatment by dialysis is estimated to be increasing by 10,000 patients per year in Japan. Furthermore, an estimated 13 million people are living with CKD in Japan. Various complications are associated with CKD, including cardiovascular disease (CVD). More than one-third of CKD patients die from CVD. Thus, prevention of CVD is a primary concern for the treatment of CKD patients. CKD-mineral and bone disorder (CKD-MBD) is a serious complication that typically leads to CVD. Hyperphosphatemia is thought to be a central-risk factor for CKD-MBD. Therefore, managing hyperphosphatemia is crucial to prevent CKD-MBD and CVD. It is difficult to achieve the target serum phosphate level through dietary modifications alone in patients with hyperphosphatemia, because most foods contain phosphate. Thus, phosphate binders such as calcium carbonate are commonly prescribed to CKD patients with hyperphosphatemia, but these have undesirable side effects. Inhibition of intestinal phosphate transport activity has also been investigated as an alternative approach for controlling serum phosphate levels in CKD patients. Nicotinamide, which is the amide of niacin, can inhibit intestinal phosphate transport. Niacin and related compounds have also been developed as drugs for hyperlipidemia conditions, especially hypertriglyceridemia with low high-density lipoprotein. This type of dyslipidemia is frequently observed in CKD patients and is a modifiable risk factor for CVD. Thus, niacin and related compounds may have utility for the treatment of both hyperphosphatemia and dyslipidemia in CKD patients to prevent CVD.

Awareness and current implementation of drug dosage adjustment by pharmacists in patients with chronic kidney disease in Japan: a web-based survey.

BackgroundThe aims of this study were to evaluate the current awareness of and implementation by pharmacists in Japan of adjustment of drug dosage according to renal function (ADDR) in patients with chronic kidney disease (CKD) and to clarify the factors influencing implementation of ADDR by community pharmacists.MethodsWe conducted a web-based questionnaire of Japanese community and hospital pharmacists. Responders were compared by characteristics, rate of implementation of ADDR, experience with adverse drug events, pharmacist awareness of implementation of ADDR, and obstacles to ADDR implementation experienced by pharmacists. Additionally, the factors influencing the implementation of ADDR by community pharmacists were investigated by logistic regression analysis.ResultsFewer community pharmacists had implemented ADDR than hospital pharmacists. The community pharmacists had less experience with adverse drug events caused by an inappropriate dosage than the hospital pharmacists, while the hospital pharmacists had encountered more severe adverse drug events than the community pharmacists. The community pharmacists had less awareness of ADDR implementation, and believed that problems in implementing ADDR were caused by a lack of information on the renal function of patients. In the logistic regression analysis, the factors influencing implementation of ADDR were “Routinely receiving prescriptions from nephrologists”, “Experience with adverse drug events caused by inappropriate dosage for CKD patients”, and “Awareness of the need for pharmacists to check the dosage of renally excreted drugs”; they did not include “Lack of information on patient renal function”.ConclusionsThis study indicates that fewer Japanese community pharmacists than hospital pharmacists implement ADDR and that implementation of ADDR by community pharmacists is hindered by their limited awareness of the importance of patient renal function. We advocate that many countermeasures be introduced to prevent CKD patients from experiencing adverse drug events caused by inappropriate dosage. Such countermeasures would include a training program to educate pharmacists about the impact of impaired renal function on dosage of drugs that are excreted by the kidneys.Electronic supplementary materialThe online version of this article (doi:10.1186/s12913-014-0615-0) contains supplementary material, which is available to authorized users.

GCK, GCKR polymorphisms and risk of chronic kidney disease in Japanese individuals: data from the J-MICC Study

Chronic kidney disease (CKD) is well known as a strong risk factor for both of end-stage renal disease and cardiovascular disease. To clarify the association of glucokinase and glucokinase regulatory protein (GCKR) polymorphisms with the risk of CKD in Japan, we examined this association among Japanese individuals using cross-sectional data. The subjects for this analysis were 3,314 consecutively selected participants from the Japan Multi-Institutional Collaborative Cohort Study. Age- and sex- adjusted odds ratios (aORs) of CKD stages 3-5 were calculated for each genotype by logistic regression and the effects of genotype on estimated glomerular filtration rate were evaluated by linear regression. Gene-environment interaction was also investigated based on questionnaire information. When subjects with GCKR rs780094 G/A and G/G, or GCKR rs1260326 T/C and C/C were combined together and compared with the references (GCKR rs780094 A/A or GCKR rs1260326 T/T), the aORs were 0.84 (0.69-1.02) or 0.81 (0.67-0.99) (p = 0.075 or 0.037), respectively. A significant OR for interaction between GCKR rs1260326 T/T and current smoking (OR = 1.79, p = 0.041) was also observed. The present study suggests a possible association of the T/T genotype of GCKR rs1260326 polymorphism with elevated risk of CKD and its interaction with current smoking, which may support the possibility of performing risk evaluation and prevention of this potentially life-threatening disease based on genetic traits in the near future.

Pre-dialysis chronic kidney disease in children: results of a nationwide survey in Japan

Chronic kidney disease (CKD) in children is a progressive and intractable condition that may severely impair the child's growth, development and quality of life. Epidemiological information on pediatric CKD, particularly in Asians, is scant. We conducted a nationwide, population-based survey of Japanese children aged 3 months to 15 years with pre-dialysis CKD to examine the prevalence of pediatric CKD in Japan. CKD was classified according to newly established criteria derived from reference serum creatinine levels in Japanese children. Surveys were sent to 1190 institutions across Japan to report on cases of pediatric CKD managed as of 1 April 2010. A total of 925 institutions (77.7%) responded. Information on 447 children was collected. When subdivided according to our diagnostic criteria, 70.5% of children had stage 3 CKD, 23.9% stage 4 and 5.6% stage 5. The estimated prevalence of Japanese children with CKD was 2.98 cases/100,000 children. Of 407 CKD cases with non-glomerular disease, 278 (68.3%) had congenital anomalies of the kidney and urinary tract (CAKUT). The newly established criteria showed good validity compared with existing criteria, including the abbreviated Schwartz equation. Findings from the first nationwide survey of pre-dialysis CKD in Asian children indicate that the prevalence of stage 3-5 CKD in children in Japan aged 3 months to 15 years is 2.98 cases/100,000 children. Most children with CKD presented with non-glomerular disease, most frequently CAKUT. Improved management of CAKUT, including renoprotective treatment and urological intervention, is required.

Burden and management of chronic kidney disease in Japan: systematic review of the literature

BackgroundChronic kidney disease (CKD) is a common disorder with increasing prevalence worldwide. This systematic literature review aims to provide insights specific to Japan regarding the burden and treatment of CKD.MethodsWe reviewed English and Japanese language publications from the last 10 years, reporting economic, clinical, humanistic, and epidemiologic outcomes, as well as treatment patterns and guidelines on CKD in Japan.ResultsThis review identified 85 relevant articles. The prevalence of CKD was found to have increased in Japan, attributable to multiple factors, including better survival on dialysis therapy and a growing elderly population. Risk factors for disease progression differed depending on CKD stage, with proteinuria, smoking, hypertension, and low levels of high-density lipoprotein commonly associated with progression in patients with stage 1 and 2 disease. Serum albumin levels and hemoglobin were the most sensitive variables to progression in patients with stage 3 and 5 disease, respectively. Economic data were limited. Increased costs were associated with disease progression, and with peritoneal dialysis as compared with either hemodialysis or combination therapy (hemodialysis + peritoneal dialysis) treatment options. Pharmacological treatments were found potentially to improve quality of life and result in cost savings. We found no reports of treatment patterns in patients with early-stage CKD; however, calcium channel blockers were the most commonly prescribed antihypertensive agents in hemodialysis patients. Treatment guidelines focused on anemia management related to dialysis and recommendations for peritoneal dialysis treatment and preventative measures. Few studies focused on humanistic burden in Japanese patients; Japanese patients reported greater disease burden but better physical functioning compared with US and European patients.ConclusionA dearth of evidence regarding the earlier stages of kidney disease presents an incomplete picture of CKD disease burden in Japan. Further research is needed to gain additional insight into CKD in Japan.

Olmesartan medoxomil and azelnidipine therapy in patients with hypertension and chronic kidney disease in Japan

In the present investigation we extracted data on hypertensive patients with chronic kidney disease (CKD) who were enrolled in 3 studies - 2 studies of the angiotensin receptor blocker (ARB) olmesartan medoxomil (OLM), lasting 12 weeks and 2 years, respectively, and one of the calcium channel blocker (CCB) azelnidipine (AZ) lasting 12 weeks - to assess the effects of OLM and AZ on blood pressure (BP), estimated glomerular filtration rate (eGFR) and proteinuria in hypertensive patients with CKD in the setting of daily clinical practice. The 3 studies followed open prospective cohort designs that represented daily clinical practice in Japan. Patients with CKD at baseline were selected. Change of BP, eGFR and proteinuria on OLM therapy or AZ therapy were analyzed. At 12 weeks, OLM (n=1,317) and AZ (n=952) therapies exhibited similar BP-lowering effects. AZ led to a significantly (p=0.0069) greater increase of eGFR compared with OLM, while OLM tended to improve proteinuria to a greater extent than AZ. Treatment with OLM for 2 years (n=109) significantly improved proteinuria but did not alter eGFR. This study shows that OLM and AZ reduced BP and proteinuria without decreasing eGFR in Japanese hypertensive patients with CKD in the setting of daily clinical practice.

Measurement of health-related quality of life in patients with chronic kidney disease in Japan with EuroQol (EQ-5D)

Chronic kidney disease (CKD) is a health-related quality-of-life (HRQOL) deteriorating disease which is not only a public health but also a socioeconomic problem. Interest in developing cost-effective interventions to control CKD has increased. The aim of this study was to measure HRQOL in terms of quality-adjustment weights for cost-effectiveness analysis using EQ-5D in patients with CKD. The relationships between the measured HRQOL and clinical indices/complications were also analyzed. EQ-5D, a generic preference-based instrument, was administered to 569 CKD outpatients at Tsukuba University Hospital between November and December 2008. The response rate was 94.4% (537/569). Data on sex, age, creatinine, hemoglobin, serum albumin and eGFR were obtained from the patients' records. Data on the presence of complications such as hypertension, diabetes, and history of cardiovascular disease (CVD) were also retrieved. Measured quality-adjustment weights by the CKD stage were 0.940 (95% CI 0.915-0.965), 0.918 (0.896-0.940), 0.883 (0.857-0.909), 0.839 (0.794-0.884), and 0.798 (0.757-0.839) for stages 1-5, respectively. The decrease in weight was significant by ANOVA (P < 0.0001), and the weight for all stages was 0.885 (0.871-0.898). There was a positive relationship between hemoglobin/serum albumin and the weight. The presence of hypertension lowered the weight from 0.910 (0.885-0.936) to 0.874 (0.858-0.891), diabetes from 0.901 (0.886-0.917) to 0.840 (0.811-0.869), and CVD from 0.892 (0.878-0.906) to 0.783 (0.718-0.848). HRQOL decreases with progression of CKD stage and/or presence of anemia, undernutrition, hypertension, diabetes, or history of CVD.

特集:慢性腎臓病(CKD)―日本人おける慢性腎臓病(CKD)対策の課題―

特集:慢性腎臓病(CKD)―日本人おける慢性腎臓病(CKD)対策の課題―

Prevalence of chronic kidney disease in the Japanese general population

We previously estimated the prevalence of chronic kidney disease (CKD) stages 3-5 at 19.1 million based on data from the Japanese annual health check program for 2000-2004 using the Modification of Diet in Renal Disease (MDRD) equation multiplied by the coefficient 0.881 for the Japanese population. However, this equation underestimates the GFR, particularly for glomerular filtration rates (GFRs) of over 60 ml/min/1.73 m(2). We did not classify the participants as CKD stages 1 and 2 because we did not obtain proteinuria data for all of the participants. We re-estimated the prevalence of CKD by measuring proteinuria using a dipstick test and by calculating the GFR using a new equation that estimates GFR based on data from the Japanese annual health check program in 2005. Data were obtained for 574,024 (male 240,594, female 333,430) participants over 20 years old taken from the general adult population, who were from 11 different prefectures in Japan (Hokkaido, Yamagata, Fukushima, Tochigi, Ibaraki, Tokyo, Kanazawa, Osaka, Fukuoka, Miyazaki and Okinawa) and took part in the annual health check program in 2005. The glomerular filtration rate (GFR) of each participant was computed from the serum creatinine value using a new equation: GFR (ml/min/1.73 m(2)) = 194 x Age(-0.287) x S-Cr(-1.094) (if female x 0.739). The CKD population nationwide was calculated using census data from 2005. We also recalculated the prevalence of CKD in Japan assuming that the age composition of the population was same as that in the USA. The prevalence of CKD stages 1, 2, 3, and 4 + 5 were 0.6, 1.7, 10.4 and 0.2% in the study population, which resulted in predictions of 0.6, 1.7, 10.7 and 0.2 million patients, respectively, nationwide. The prevalence of low GFR was significantly higher in the hypertensive and proteinuric populations than it was in the populations without proteinuria or hypertension. The prevalence rate of CKD in Japan was similar to that in the USA when the Japanese general population was age adjusted to the US 2005 population estimate. About 13% of the Japanese adult population-approximately 13.3 million people-were predicted to have CKD in 2005.

Risk factors for chronic kidney disease in Japan: a community-based study

BackgroundChronic kidney disease (CKD) is increasingly being recognized as a predictor for both end-stage renal disease and cardiovascular disease. The present study, conducted on individuals from a community in Arita, Japan, was designed to evaluate biomarkers that can be used to determine the associated factors for CKD.MethodsThis study involved 1554 individuals. Kidney function was evaluated in terms of the creatinine-based estimated glomerular filtration rate (eGFR), which was determined using the Modification of Diet in Renal Disease equation. Low eGFR was defined as eGFR < 60 mL/min per 1.73 m2. The concentration of both urinary albumin and urinary type IV collagen were measured.ResultsIn the younger participants (age, <65 years), the odds ratio (95% confidence interval [CI]) of low eGFR was 1.17 (1.02 to 1.34) for each 1 year older age, 6.28 (1.41 to 28.03) for urinary albumin creatinine ratio (ACR) over 17.9 mg/g and 9.43 (2.55 to 34.91) for hyperlipidemia. On the other hand, among the elderly participants (age, ≥ 65 years), the odds ratio (95% CI) of low eGFR was 2.97 (1.33 to 6.62) for gender, 1.62 (1.06 to 2.50) for hypertension and 1.97 (1.19 to 3.28) for hyperlipidemia. Urinary type IV collagen creatinine ratio was not identified as an associated factor for low eGFR.ConclusionIn this present cross-sectional community-based study, ACR is associated with CKD, which was defined as an eGFR of less than 60 mL/min per 1.73 m2, in the younger participants but not in the older participants.

Chronic Kidney Disease in Japan

Chronic kidney disease (CKD) is defined as either kidney damage with urine, imaging, and histologic abnormalities, or a low estimated glomerular filtration rate (GFR) for more than 3 months. The GFR is calculated using either the Modification of Diet in Renal Disease (MDRD) Study equation or the Cockcroft-Gault formula. CKD is a risk factor for end-stage renal disease (ESRD) and cardiovascular disease. In Japan, the prevalence of ESRD is increasing and is currently more than 2,000 per million population. More than 40% of incident ESRD is due to diabetes mellitus (DM). The prevalence of a low GFR (< 60 ml/min/1.73 m(2)) is estimated to be 20% of the adult population. Studies based on several community-based screening programs suggest that Japan has a higher prevalence of CKD than any other country. Early detection and treatment of CKD are necessary to decrease the incidence of ESRD and cardiovascular disease.

Chronic Kidney Disease Japan Cohort (CKD-JAC) Study: Design and Methods

The prevalence and incidence of end-stage renal disease (ESRD) in Japan are the highest and the third highest, respectively, in the world, while the incidence of cardiac death in Japan is the lowest among developed countries. A recent study showed that the prevalence of chronic kidney disease (CKD), defined as an estimated glomerular filtration rate (GFR) of less than 60 mL/min/1.73 m(2), is extremely high in Japan, about 20% of the adult population. However, the risk of ESRD and cardiovascular disease (CVD) in the CKD population has not been determined nationwide. For this observational study, we will establish a Chronic Kidney Disease Japan Cohort (CKD-JAC) by enrolling 3,000 patients with CKD in 17 clinical centers around Japan, which will be used to determine the incidence of ESRD and CVD in Japanese CKD patients. Risk factors associated with the development of CVD will also be examined. Comorbidity of diabetes in CKD patients will be analyzed to determine whether it is a risk for rapid progression of CKD and high incidence of CVD. In addition, we will study whether the burden of CKD decreases the QOL of patients, and increases hospitalization or health resource utilization. Insights from the CKD-JAC study will provide a basis for future interventional trials focused on reducing the burden of ESRD and CVD in patients with CKD in Japan.