Effect of PM2.5 for hospitalization of cardiovascular diseases and medical expenses by age group: a nationwide study from the Japanese Registry Of All cardiac and vascular Diseases (JROAD)

Introduction

Although particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) exposure influences cardiovascular events, there is limited knowledge how PM2.5 exposure is associated with cardiovascular hospitalization in Japan.

Purpose

We tested the hypothesis that PM2.5 exposure was related to the number of cardiovascular hospitalizations, hospitalization period, and medical expenses.

Methods

We included 835,405 subjects who were admitted to acute care hospitals in Japan. We classified PM2.5 exposure concentration into quintile groups (from low to high in the order of “PM-1” to “PM-5” group). Multilevel mixed-effects Poisson and linear regression analysis were used to estimate the association of PM2.5 exposure concentration with the cardiovascular hospitalization events, duration and medical expenses. We also analyzed those factors classified by age.

Results

PM-2, 3, 4, 5 group were positively related to the number of cardiovascular hospitalization events compared with PM-1 group (Table 1). PM-3, 4, 5 group were positively associated with a 0.018, 0.029, and 0.029 (all p<0.001) of the difference of log cardiovascular hospitalization period compared with PM-1 group (p for trend <0.001). These groups were also positively associated with a 0.016, 0.023, and 0.021 (all p<0.001) of the difference of log medical expenses compared with PM-1 group (p for trend <0.001). Analyzed by age group, hospitalization duration was longer (p<0.05) and medical expenses was lower (p<0.05) significantly in super-aging group (over 90 years old) than the group under 64 years old (Figure 1).

Conclusions

PM2.5 exposure concentration has harmful effect on not only cardiovascular events but cardiovascular hospitalization period and medical expenses due to big-data in Japan. Medical costs were kept low in comparison with their hospitalization period in subjects over 90 years old.

Figure 1

Funding Acknowledgement

Type of funding source: None

Differences in Corrective Mode for Divalent Ions and Parathyroid Hormone between Standard- and Low-Calcium Dialysate in Patients on Continuous Ambulatory Peritoneal Dialysis—Result of a Nationwide Survey in Japan

⋄ Background

In patients on continuous ambulatory peritoneal dialysis (CAPD), dialysate calcium concentration has a strong influence on correction of serum calcium, phosphorus, and parathyroid hormone (PTH); however, the optimal concentration of Ca in PD solution is still uncertain. The aim of the survey reported here was to evaluate the prevalence of patients treated with standard- [SCD (approximately 3.25 – 4.0 mEq/L)] or low-calcium [LCD (approximately 1.8 – 2.5 mEq/L)] dialysate and differences in the clinical effects for correction of abnormalities in divalent ions and PTH.

⋄ Materials and Methods

We used a questionnaire to survey 333 peritoneal dialysis facilities nationwide in Japan. Then, we analyzed serum Ca, P, and PTH levels and the prescription rates for CaCO3 as a P binder and for vitamin D (VitD) analogs.

⋄ Results

The 2384 CAPD patients enrolled in this analysis had a mean age of 60.5 ± 14.2 years and a mean duration of CAPD of 44.1 ± 39.2 months. The prevalences of SCD, LCD, and combination of SCD and LCD were, respectively, 49%, 50%, and 1% at initiation, and 40%, 38%, and 22% at the time of the survey. In 735 and 876 patients respectively, LCD and SCD had been prescribed from initiation to the time of the survey. In these two groups, we observed no difference in initiation and current serum levels of Ca and P. But prescription rates for CaCO3 and VitD analogs were higher in the LCD group than in the SCD group, and PTH levels were higher in the LCD group than in the SCD group.

⋄ Conclusions

A beneficial effect of LCD was revealed in the increased doses of CaCO3 and VitD analogs seen in that group without the occurrence of hypercalcemia; however, PTH levels in that group were not maintained within an acceptable range. The survey suggests that more serious attention should be paid to the Ca concentration in peritoneal dialysate so as to lessen mineral and PTH disorders in CAPD.

Mizoribine therapy combined with steroids and mizoribine blood concentration monitoring for idiopathic membranous nephropathy with steroid-resistant nephrotic syndrome

Background

We designed a prospective and randomized trial of mizoribine (MZR) therapy combined with prednisolone (PSL) for idiopathic membranous nephropathy (IMN) with steroid-resistant nephrotic syndrome (SRNS).

Methods

Patients with IMN were divided into 2 groups, and MZR combined with PSL was administered for 2 years. PSL was initially prescribed at 40 mg/day and tapered. MZR was given once-a-day at 150 mg and 3-times-a-day at 50 mg each to groups 1 and 2. Serum MZR concentrations from 0 to 4 h after administration were examined within one month of treatment. The concentration curve and peak serum level (C_max) of MZR were estimated by the population pharmacokinetic (PPK) parameters of MZR.

Results

At 2 years, 10 of 19 patients (52.6 %) in group 1 and 7 of 18 patients (38.9 %) in group 2 achieved complete remission (CR). The time-to-remission curve using the Kaplan–Meier technique revealed an increase in the cumulative CR rate in group 1, but no significant difference between the groups. Meanwhile, there was a significant difference in C_max between groups 1 and 2 (mean ± SD: 1.20 ± 0.52 vs. 0.76 ± 0.39 μg/mL, p = 0.04), and C_max levels in CR cases were significantly higher than those in non-CR cases. Receiver operating characteristic analysis showed that C_max more than 1.1 µg/mL was necessary for CR in once-a-day administration.

Conclusion

Administration of MZR once a day is useful when combined with PSL for treatment of IMN with SRNS. In addition, it is important to assay the serum concentration of MZR and to determine C_max, and more than 1.1 µg/mL of C_max is necessary for CR.

Effect of Behavior Modification on Outcome in Early- to Moderate-Stage Chronic Kidney Disease: A Cluster-Randomized Trial

OBJECTIVES

Owing to recent changes in our understanding of the underlying cause of chronic kidney disease (CKD), the importance of lifestyle modification for preventing the progression of kidney dysfunction and complications has become obvious. In addition, effective cooperation between general physicians (GPs) and nephrologists is essential to ensure a better care system for CKD treatment. In this cluster-randomized study, we studied the effect of behavior modification on the outcome of early- to moderate-stage CKD.

DESIGN

Stratified open cluster-randomized trial.

SETTING

A total of 489 GPs belonging to 49 local medical associations (clusters) in Japan.

PARTICIPANTS

A total of 2,379 patients (1,195 in group A (standard intervention) and 1,184 in group B (advanced intervention)) aged between 40 and 74 years, who had CKD and were under consultation with GPs.

INTERVENTION

All patients were managed in accordance with the current CKD guidelines. The group B clusters received three additional interventions: patients received both educational intervention for lifestyle modification and a CKD status letter, attempting to prevent their withdrawal from treatment, and the group B GPs received data sheets to facilitate reducing the gap between target and practice.

MAIN OUTCOME MEASURE

The primary outcome measures were 1) the non-adherence rate of accepting continuous medical follow-up of the patients, 2) the collaboration rate between GPs and nephrologists, and 3) the progression of CKD.

RESULTS

The rate of discontinuous clinical visits was significantly lower in group B (16.2% in group A vs. 11.5% in group B, p = 0.01). Significantly higher referral and co-treatment rates were observed in group B (p<0.01). The average eGFR deterioration rate tended to be lower in group B (group A: 2.6±5.8 ml/min/1.73 m2/year, group B: 2.4±5.1 ml/min/1.73 m2/year, p = 0.07). A significant difference in eGFR deterioration rate was observed in subjects with Stage 3 CKD (group A: 2.4±5.9 ml/min/1.73 m2/year, group B: 1.9±4.4 ml/min/1.73 m2/year, p = 0.03).

CONCLUSION

Our care system achieved behavior modification of CKD patients, namely, significantly lower discontinuous clinical visits, and behavior modification of both GPs and nephrologists, namely significantly higher referral and co-treatment rates, resulting in the retardation of CKD progression, especially in patients with proteinuric Stage 3 CKD.

TRIAL REGISTRATION

The University Hospital Medical Information Network clinical trials registry UMIN000001159.

Downregulation of transient receptor potential M6 channels as a cause of hypermagnesiuric hypomagnesemia in obese type 2 diabetic rats

We assessed the expression profile of Mg2+-transporting molecules in obese diabetic rats as a cause of hypermagnesiuric hypomagnesemia, which is involved in the development of insulin resistance, hypertension, and coronary diseases. Kidneys were obtained from male Otsuka Long-Evans Tokushima fatty (OLETF) and Long-Evans Tokushima Otsuka (LETO) obese diabetic rats at the ages of 16, 24, and 34 wk. Expression profiles were studied by real-time PCR and immunohistochemistry together with measurements of urine Mg2+excretion. Urine Mg2+excretion was increased in 24-wk-old OLETF rats and hypomagnesemia was apparent in 34-wk-old OLETF rats but not in LETO rats (urine Mg2+excretion: 0.16 ± 0.01 μg·min−1·g body wt−1in 24-wk-old LETO rats and 0.28 ± 0.01 μg·min−1·g body wt−1in 24-wk-old OLETF rats). Gene expression of transient receptor potential (TRP)M6 was downregulated (85.5 ± 5.6% in 34-wk-old LETO rats and 63.0 ± 3.5% in 34-wk-old OLETF rats) concomitant with Na+-Cl−cotransporter downregulation, whereas the expression of claudin-16 in tight junctions of the thick ascending limb of Henle was not different. The results of the semiquantitative analysis of immunohistochemistry were consistent with these findings (TRPM6: 0.49 ± 0.04% in 16-wk-old LETO rats, 0.10 ± 0.01% in 16-wk-old OLETF rats, 0.52 ± 0.03% in 24-wk-old LETO rats, 0.10 ± 0.01% in 24-wk-old OLETF rats, 0.48 ± 0.02% in 34-wk-old LETO rats, and 0.12 ± 0.02% in 34-wk-old OLETF rats). Gene expression of fibrosis-related proinflammatory cytokines as well as histological changes showed that the hypermagnesiuria-related molecular changes and tubulointerstitial nephropathy developed independently. TRPM6, located principally in distal convoluted tubules, appears to be a susceptible molecule that causes hypermagnesiuric hypomagnesemia as a tubulointerstitial nephropathy-independent altered tubular function in diabetic nephropathy.

Clinical significance of fractional magnesium excretion (FEMg) as a predictor of interstitial nephropathy and its correlation with conventional parameters

BACKGROUND

Elevated urine Mg excretion and its correlation with histological damage in tubulo-interstitial nephropathy (TIN) were reported. Here we investigated the clinical significance of the fractional excretion of Mg (FEMg) for the prediction of TIN.

METHODS

We enrolled and assessed 94 adult patients with various renal diseases diagnosed principally by renal biopsy.

RESULTS

Our stratified analysis based on the value of the conventional TIN parameter N-acetylglucosaminidase (NAG) excretion showed that the high-NAG index group (more than median value of NAG-to-Cr ratio, n = 47) demonstrated significantly high FEMg values (p = 0.017). A univariate analysis revealed a significant correlation between the FEMg and the NAG index (R = 0.60) but not for other parameters. A multivariate regression analysis confirmed the significance of the FEMg as an effective predictor of the NAG index. The FEMg showed a significant correlation with the estimated glomerular filtration rate (eGFR) in the patients with eGFR ≤ 30 mL/min. The correlation of FEMg with the NAG index was not observed in the primary glomerulonephritis patients but was apparent in the patients with hypertensive nephrosclerosis or interstitial nephritis.

CONCLUSION

Our findings may indicate that the combination of the FEMg and the NAG index can provide a specific, sensitive assessment for TIN in patients without renal insufficiency.

A case of water intoxication with prolonged hyponatremia caused by excessive water drinking and secondary SIADH

Water intoxication is a life-threatening disorder accompanied by brain function impairment due to severe dilutional hyponatremia. We treated a 22-year-old man without psychotic illness who had been put in a detention facility. He drank 6 liters of water over a 3-hour period at the facility as a game's penalty, and he showed progressive psychiatric and neurological signs including restlessness, peculiar behavior and convulsions. On his admission, 15 h after the discontinuation of the water drinking, he was in a coma, showing intermittent convulsions and remarkable hyponatremia (120 mmol/l). Because his laboratory tests showed hypertonic urine and normal sodium excretion, the diagnosis of secondary development of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) was strongly suggested and later confirmed by the suppression of the renin-aldosterone system and the inappropriately elevated secretion of ADH. Saline infusion and an initial administration of furosemide in addition to dexamethasone as treatments for the patient's brain edema successfully improved his laboratory data and clinical signs by the 3rd hospital day, and he was returned to the facility without physical or psychiatric abnormalities on the 6th day. The secondary SIADH might have been due to the prolonged emesis, recurrent convulsions and rapid elevation of intracranial pressure.

Significance of combined cyclosporine-prednisolone therapy and cyclosporine blood concentration monitoring for idiopathic membranous nephropathy with steroid-resistant nephrotic syndrome: a randomized controlled multicenter trial

Background

Combined treatment with cyclosporine microemulsion preconcentrate (CyA MEPC) and steroids has been widely used for idiopathic membranous nephropathy (IMN) associated with steroid-resistant nephrotic syndrome (SRNS). Recent studies have shown that once-a-day and preprandial administration of CyA MEPC is more advantageous than the conventional twice-a-day administration in achieving the target blood CyA concentration at 2 h post dose (C2). We designed a randomized trial to compare these administrations.

Methods

IMN patients with SRNS (age 16–75 years) were divided prospectively and randomly into 2 groups. In group 1 (n = 23), 2–3 mg/kg body weight (BW) CyA MEPC was given orally once a day before breakfast. In group 2 (n = 25), 1.5 mg/kg BW CyA MEPC was given twice a day before meals. CyA + prednisolone was continued for 48 weeks.

Results

Group 1 showed a significantly higher cumulative complete remission (CR) rate (p = 0.0282), but not when incomplete remission 1 (ICR1; urine protein 0.3–1.0 g/day) was added (p = 0.314). Because a C2 of 600 ng/mL was determined as the best cut-off point, groups 1 and 2 were further divided into subgroups A (C2 ≥600 ng/mL) and B (C2 <600 ng/mL). Groups 1A and 2A revealed significantly higher cumulative remission (CR + ICR1) (p = 0.0069) and CR-alone (p = 0.0028) rates. On the other hand, 3 patients with high CyA levels (C2 >900 ng/mL) in Group 1A were withdrawn from the study because of complications.

Conclusion

CyA + prednisolone treatment is effective for IMN with associated SRNS at a C2 of ≥600 ng/mL. To achieve remission, preprandial once-a-day administration of CyA at 2–3 mg/kg BW may be the most appropriate option. However, we should adjust the dosage of CyA by therapeutic drug monitoring to avoid complications.

Release from glomerular overload by the addition of low-dose thiazide in patients with angiotensin receptor blocker-resistant hypertension

BACKGROUND/AIMS

This multicenter, prospective, observational study assessed the renoprotective effects of losartan/thiazide combination therapy in terms of lowering the estimated glomerular filtration rate (eGFR).

METHODS

Adult patients with angiotensin receptor blocker (ARB)-resistant essential hypertension (n = 104) were enrolled and switched to combination therapy with losartan (50 mg/day) and hydrochlorothiazide (12.5 mg/day).

RESULTS

eGFR values declined significantly during the first 3 months, and changes in eGFR were assessed according to tertiles of the eGFR decrease ratio at 3 months. Only the high eGFR decrease (1st tertile) group showed significantly greater decreases in baseline eGFR and albumin-to-creatinine ratio (ACR) during the first 3 months. Additionally, the assessment according to tertiles of the baseline eGFR showed a signifcant decrease in eGFR and ACR during the first 3 months in the high baseline eGFR (1st tertile) group, but not in the moderate (2nd tertile) and low baseline eGFR (3rd tertile) groups.

CONCLUSION

The present results revealed that losartan/thiazide combination therapy attenuated glomerular overload, indicating that this therapy may provide glomerular protection in patients with an elevated GFR without causing prolonged damage to renal function.

Renoprotective effect of pioglitazone by the prevention of glomerular hyperfiltration through the possible restoration of altered macula densa signaling in rats with type 2 diabetic nephropathy

BACKGROUND/AIMS

Pioglitazone (PGZ), one of the thiazolidinediones, has been known to show renoprotective effects. In this study, we focused on the effect of PGZ on glomerular hyperfiltration (GHF), resultant glomerular injury and altered macula densa signaling as a cause of sustained GHF through modified tubuloglomerular feedback in rats with diabetic nephropathy.

METHODS

Kidneys from 24-week-old male OLETF rats and LET rats, nondiabetic controls, were used for the experiment. PGZ was administered (10 mg/kg/day, p.o.) for 2 weeks from 22 to 24 weeks of age in some of the OLETF rats (OLETF+PGZ).

RESULTS

Parameters relating GHF, kidney weight, creatinine clearance, urine albumin/creatinine ratio and glomerular surface were all increased in OLETF rats and partially restored in OLETF+PGZ rats. Expressions of desmin and TGF-β were also increased in OLETF rats and restored in OLETF+PGZ rats. The changes in TGF-β expression were confirmed to be independent of podocyte number. Finally, the immunoreactivity of neuronal nitric oxide synthase (nNOS) and cyclooxygenase 2 (COX-2) in the macula densa was assessed for the evaluation of macula densa signaling. Altered intensities of nNOS and COX-2 in OLETF rats were restored in OLETF+PGZ rats, which agreed with the gene expression analysis (nNOS: 100.2 ± 2.9% in LET, 64.2 ± 2.7% in OLETF, 87.4 ± 12.1% in OLETF+PGZ; COX-2: 100.8 ± 7.4% in LET, 249.2 ± 19.4% in OLETF, 179.9 ± 13.5% in OLETF+PGZ; n = 5) and the semiquantitative analysis of nNOS/COX-2-positive cells.

CONCLUSION

PGZ effectively attenuated the GHF and hyperfiltration-associated glomerular injury in diabetic nephropathy. The restoration of altered macula densa signaling might be involved in the renoprotective effect of PGZ.

Endogenous factors modified by hemodialysis may interfere with the accuracy of blood glucose-measuring device

In Japan, self-monitoring of blood glucose (SMBG) devices are widely used both at home and in hospitals, but many analytical errors and safety concerns have been reported about the SMBG devices used in hospitals. Analytical performances of StatStrip (Nova Biomedical Corporation, MA, USA), a new point-of-care testing device and Glutest (Sanwa Chemical, Aichi, Japan), a routinely used SMBG device were compared in glucose measurement of pre- and postdialysis blood samples and we evaluated which factors in blood modified by hemodialysis affect accuracy of these devices. Subjects in this study were 44 hemodialysis patients. Blood samples were obtained from patients just before and just after the hemodialysis. Blood glucose concentrations of samples were measured by StatStrip and Glutest. Hematocrit and plasma concentrations of electrolytes, metabolites, etc. of the samples were measured in the central laboratory. StatStrip showed no difference between pre- and postdialysis blood samples and showed very little bias from reference method. On the other hand, Glutest showed difference between pre- and postdialysis samples. Although there is no problem in the data of predialysis blood samples by Glutest, however, these of the postdialysis blood samples by Glutest were >10% less than reference method. Factors in blood modified by hemodialysis such as hematocrit, uric acid, albumin, potassium, and calcium affected glucose readings by Glutest. Glucose readings by Glutest of samples from hemodialysis patients were affected by hematocrit and several factors, which were modified by hemodialysis. StatStrip is considered as a better device in dialysis hospitals.

The efficacy of intensive granulocyte and monocyte adsorption apheresis in a patient with Crohn's disease complicated by extensive subcutaneous aseptic neutrophilic abscesses

BACKGROUND AND AIMS

Subcutaneous aseptic abscess is one phenotype of neutrophilic dermatitis. We were interested to see if a case of steroid refractory Crohn's disease (CD) complicated by subcutaneous aseptic neutrophilic abscesses responds to intensive granulocyte/monocyte adsorptive apheresis (GMA).

METHODS

The patient was a 21-year-old male with worsening severe CD while on oral prednisolone (30 mg/day). His symptoms included fever, bloody diarrhoea and multiple painful subcutaneous nodules throughout his body. Skin biopsy showed chronic panniculitis with neutrophilic infiltrates. Further, colonoscopy showed oedematous sigmoid colon, while colonic biopsy showed non-caseous granuloma. Because biologics were feared to increase the risk of bacteraemia as the result of germ culture on his pus was not known at the time, we decided to treat this case with GMA. Five GMA sessions with the Adacolumn over 5 consecutive days (daily GMA) were initiated.

RESULTS

On admission, his CD activity index (CDAI) was 355, C-reactive protein (CRP) 11.2 mg/dL. After 5 GMA sessions, CDAI decreased to 170, and CRP fell to 5.0 mg/dL, with no fever. GMA was restarted at 2 sessions/week (total 10 sessions). The patient's CDAI fell to <150, and the skin lesions re-epithelialized.

CONCLUSIONS

In this CD case complicated by subcutaneous aseptic neutrophilic abscesses, GMA appeared to be effective. Our impression is that when biopsy reveals neutrophil infiltrate is a major feature of the lesions, GMA should be considered. As GMA appears to have no safety concerns, a frequent GMA protocol, like daily followed by 2 to 3 times/week should be preferred over the routine weekly GMA.

Contribution of residual renal function on peritoneal solute transport in dialysis patients

BACKGROUND

Increased peritoneal solute transport rate (PSTR) is primarily a consequence of continuous exposure to bioincompatible glucose-based peritoneal dialysis (PD) solutions. However, relationships between increasing PSTR and dialysate glucose load remain unclear. As some PD patients with preserved residual renal function do not show increased PSTR despite long-term PD, we examined whether loss of residual renal function is associated with increased PSTR on long-term PD.

METHODS

We evaluated 35 patients who started PD between 1997 and 2002 and received continuous PD treatment for >6 years. Data included baseline clinical data, residual renal function, urea and creatinine clearance, dialysate glucose load, ultrafiltration, and the use of icodextrin and renin-angiotensin system inhibitors. Peritoneal equilibration test results and data were collected annually for 6 years.

RESULTS

Both the glomerular filtration rate and urine volume at 6 years on PD showed significant negative correlations with the dialysate-to-plasma creatinine ratio (D/P Cr) at 6 years (r = -0.716 and r = -0.717, respectively). Multivariate analysis showed only urine volume at 6 years on PD as an independent covariate of the D/P Cr at 6 years on PD.

CONCLUSIONS

Loss of residual renal function is directly associated with increased PSTR in patients on long-term PD.

[Predictive value of ultrasonographical assessments of carotid artery for cardiovascular events in patients under hemodialysis: add on comparison with stroke patients]

BACKGROUND

The prognosis of patients on hemodialysis (HD) was determined with respect to cardiovascular disease. We analyzed the relationships between several parameters of carotid artery echograms and cardiovascular events (CVE) in patients on HD. We also compared the characteristic findings of carotid artery echography in patients with stroke and patients on HD.

METHOD

We enrolled 104 patients on HD (male : female, 72: 32; mean age, 63.0 +/- 11.2 years) and 48 with stroke (male : female, 36: 12; mean age, 66.0 +/- 7.7 years) who were admitted to our hospital between 1998 and 2004. We measured intima media thickness (IMT), plaque score (PS), resistive index (RI), common carotid artery (CCA) stenosis and plaque echogenicity using B-mode ultrasonography. The correlation between carotid artery echographic findings and CVE were analyzed over a period of 37.5 +/- 22.9 months of follow-up. The characteristic findings of carotid artery echography were compared among groups of patients on initial HD (iHD) and maintenance HD (mHD) and with stroke accompanied by eGFR > 60 mL/min/1.73 m2.

RESULTS

Both PS and RI significantly correlated with CVE (p < 0.005 and p < 0.05, respectively), and CVE occurred at the early phase of follow up in patients with increased PS. Both PS and RI were also higher in mHD than in stroke (p < 0.005). Both PS and CCA stenosis were higher in mHD than in iHD (p < 0.01, p< 0.05). More hard plaques were identified in patients on mHD than in those with stroke (p < 0.005). Multivariate analysis showed that the numbers of soft and hard plaques were significantly associated with CCA stenosis(p < 0.05) and the duration of dialysis (p < 0.05), respectively.

CONCLUSIONS

Increasing PS and RI were powerful predictors of CVE in patients on HD. Atherosclerotic changes were equal in patients on iHD and those with stroke. Plaque score, the numbers of hard plaques and CCA stenosis were increased in mHD, suggesting the development of atherosclerotic changes in patients on HD.

Design and methods of a strategic outcome study for chronic kidney disease: Frontier of Renal Outcome Modifications in Japan

BACKGROUND

The continuous increase in the number of people requiring dialysis is a major clinical and socioeconomical issue in Japan and other countries. This study was designed to encourage chronic kidney disease (CKD) patients to consult a physician, enhance cooperation between nephrologists and general practices, and prevent the progression of kidney disease.

METHODS

Subjects comprise CKD patients aged between 40 and 74 years consulting a general physician, and patients in CKD stage 3 with proteinuria and diabetes or hypertension. This trial is a stratified open cluster-randomized study with two intervention groups: group A (weak intervention) and group B (strong intervention). We have recruited 49 local medical associations (clusters) in 15 different prefectures, which were classified into four regions (strata) based on the level of increase rate of dialysis patients. The patients in group A clusters were instructed initially to undergo treatment in accordance with the current CKD treatment guide, whereas patients in group B clusters were not only instructed in the same fashion but also received support from an information technology (IT)-based system designed to help achieve the goals of CKD treatment, consultation support centers, and consultations by dietitians visiting the local general practice offices. We assessed the rates of continued consultation, collaboration between general practitioners and nephrologists, and progression of CKD (as expressed by CKD stage).

CONCLUSION

Through this study, filling the evidence-practice gap by facilitating effective communication and supporting general physicians and nephrologists, we will establish a CKD care system and decrease the number of advanced-stage CKD patients.

Differences in corrective mode for divalent ions and parathyroid hormone between standard- and low-calcium dialysate in patients on continuous ambulatory peritoneal dialysis--result of a nationwide survey in Japan

BACKGROUND

In patients on continuous ambulatory peritoneal dialysis (CAPD), dialysate calcium concentration has a strong influence on correction of serum calcium, phosphorus, and parathyroid hormone (PTH); however, the optimal concentration of Ca in PD solution is still uncertain. The aim of the survey reported here was to evaluate the prevalence of patients treated with standard- [SCD (approximately 3.25 - 4.0 mEq/L)] or low-calcium [LCD (approximately 1.8 - 2.5 mEq/L)] dialysate and differences in the clinical effects for correction of abnormalities in divalent ions and PTH.

MATERIALS AND METHODS

We used a questionnaire to survey 333 peritoneal dialysis facilities nationwide in Japan. Then, we analyzed serum Ca, P, and PTH levels and the prescription rates for CaCO(3) as a P binder and for vitamin D (VitD) analogs.

RESULTS

The 2384 CAPD patients enrolled in this analysis had a mean age of 60.5 +/- 14.2 years and a mean duration of CAPD of 44.1 +/- 39.2 months. The prevalences of SCD, LCD, and combination of SCD and LCD were, respectively, 49%, 50%, and 1% at initiation, and 40%, 38%, and 22% at the time of the survey. In 735 and 876 patients respectively, LCD and SCD had been prescribed from initiation to the time of the survey. In these two groups, we observed no difference in initiation and current serum levels of Ca and P. But prescription rates for CaCO(3) and VitD analogs were higher in the LCD group than in the SCD group, and PTH levels were higher in the LCD group than in the SCD group.

CONCLUSIONS

A beneficial effect of LCD was revealed in the increased doses of CaCO(3) and VitD analogs seen in that group without the occurrence of hypercalcemia; however, PTH levels in that group were not maintained within an acceptable range. The survey suggests that more serious attention should be paid to the Ca concentration in peritoneal dialysate so as to lessen mineral and PTH disorders in CAPD.

[Several PTH assay and the problem]

Parathyroid hormone (PTH) is the most important molecule used as the indicator of a bone and mineral metabolism including renal insufficiency patients. With the elucidation of the PTH molecule, the measuring method of the serum PTH concentration has changed. The intact PTH assay has been carried out as most general PTH assay until recently, and it is measured with the some kits. It is proposed the several problems, as some kinds differ between these kits including with the sensitivity and specificity. Moreover, in the PTH molecule which exists in the human serum, many fragments existed besides 1-84 PTH. It became clear by the intact PTH assay to have measured 7-84 PTH simultaneously with 1-84 PTH. And then the measuring method which detects only 1-84 PTH was developed. But the report of clinical future with specific 1-84 PTH measurement is not enough as evidence. It is expected that clinical meaning with 1-84 PTH specific measurement will be examined moreover.

Citrullination preferentially proceeds in glomerular Bowman's capsule and increases in obstructive nephropathy

BACKGROUND

Peptidylarginine deiminases (PADs) are a group of posttranslational modification enzymes that citrullinate (deiminate) protein arginine residues, yielding citrulline residues. Citrullination of arginine residues abolishes their positive charge, markedly altering their structure. We undertook this study to investigate the actions of PADs in the kidney.

METHODS

In male rats, we ligated the unilateral ureter, then analyzed the obstructed and contralateral kidneys 1 week later. Controls were rats simultaneously given sham operations. In another experiment, we ligated unilateral ureters of eight rats, four of which received a ureter-bladder anastomosis 1 week later. These rats were subjected to histologic examinations 5 weeks after unilateral ureteral obstruction (UUO).

RESULTS

Reverse transcription-polymerase chain reaction (RT-PCR) revealed that, of PADs (type I, II, III, and IV), only PAD type II was expressed in kidneys. Western blot study showed that PAD type II expression and citrullinated protein content increased greatly in kidneys that underwent unilateral ureteral ligation compared to that in contralateral or sham-operated kidneys. Immunohistochemical analyses revealed that PAD type II was preferentially expressed by parietal epithelial cells and that only in Bowman's capsule were proteins citrullinated. Additionally, these PAD type II and citrullinated proteins in obstructed nephropathy were significantly attenuated by the release of the obstruction. Proteome analysis revealed that one of citrullinated proteins in the kidney should be actin.

CONCLUSION

This result indicates that PAD type II and citrullinated proteins are suitable markers of Bowman's capsule. Not only are these markers preferentially expressed in Bowman's capsules but their expression is also increased in damaged kidneys by UUO, features that promise the further clarification of kidney diseases.

Prognosis and risk factors for idiopathic membranous nephropathy with nephrotic syndrome in Japan

BACKGROUND

Idiopathic membranous nephropathy (IMN) is a representative form of refractory nephrotic syndrome in Japan. Although IMN is thought to run a more benign course in Japanese than in the Caucasian population, risk factors and appropriate treatment are controversial issues.

METHODS

The research group supported by a grant for "Progressive Renal Disease" from the Ministry of Health, Labor and Welfare, Japan, carried out a national survey of patients with IMN and nephrotic syndrome. Of 1066 nephrotic patients with histopathologically proven IMN registered from 1975 to 1993 in 85 institutions, 949 patients were studied.

RESULTS

The overall renal survival rates were 95.8%, 90.3%, 81.1%, and 60.5% at 5, 10, 15, and 20 years after diagnosis, respectively. When clinical and histopathologic features at onset of nephrotic syndrome were evaluated by multivariate analysis, male gender, old age (> or =60 years), high serum creatinine concentration (> or =1.5 mg/dL), and the development of tubulointerstitial lesions (> or =20% of the biopsy sample area) were significant predictors of progression to end-stage renal disease (ESRD). The renal survival rate in patients on steroid therapy was significantly higher than in patients on supportive therapy alone. Patients achieving a remission showed a significant reduction of risk for progression.

CONCLUSION

IMN is a disease with a comparatively good prognosis in Japan even when it is associated with nephrotic syndrome. Steroid therapy, which has not been recommended for IMN in most review articles, seems to be useful at least for Japanese patients. In particular, a remission from heavy proteinuria likely results in a favorable outcome.

[Prevention and management of complications in nephrotic syndrome]

Nephrotic syndrome is defined as the glomerular disease with massive proteinuria and hypoalbuminemia, and complications are numerous. Among these complications, saltwater retention, thromboembolism, hyperlipidemia, metabolic bone disease, infections are important for management of nephrotic syndrome. Recent advances in the understanding of alterations in the metabolism of circulating and somatic proteins associated with proteinuria and hypooncotic condition have led to new insights into the pathophysiologic processes associated with this syndrome. Therapeutic consideration should be paid not only for the treatment of primary diseases, but also for the prevention of these complications.

A randomized open-label comparative study of conventional therapy versus mizoribine onlay therapy in patients with steroid-resistant nephrotic syndrome (postmarketing survey)

BACKGROUND

A previous double-blind 24-week clinical trial of mizoribine (MZ) vs placebo in steroid-resistant primary nephrotic syndrome (SRPNS) showed that MZ was more effective than placebo in reducing the rate of deterioration of renal function. The present study was conducted to evaluate the efficacy and safety of MZ in patients with SRPNS after 2 years' treatment.

METHODS

A multicenter randomized open-label controlled trial in patients with SRPNS was conducted as a 2-year prospective postmarketing study.

RESULTS

There was a significant imbalance in the baseline serum albumin level (s-Alb) between the conventional therapy (CT) and MZ onlay therapy groups. Early dropouts were more frequent in the subset of patients in the CT group having a baseline s-Alb < or =3 g/dl. Therefore, the primary analysis (urinary protein level (UP)-improving effect) was performed using a mixed-effects model, with stratification according to the baseline s-Alb value. The analysis revealed that, in the subset of 34 patients with membranous nephropathy (MN) within the stratum of patients with baseline s-Alb < or =3 g/dl (n = 52), the rate of change (slope of change in the UP level/month), in terms of the log (UP+0.2), was -0.0577 in those allocated to the MZ group and -0.0227 in those allocated to the CT group (P = 0.058). In the stratum of patients with a baseline s-Alb >3 g/dl (n = 97), there were no significant differences in the UP between the two treatment groups. Hence, MZ onlay therapy was not considered to be efficacious in this group of patients. No serious adverse reactions to the drug were observed.

CONCLUSIONS

The present study yielded significant results, in that it suggested the possibility that long-term MZ therapy may afford further reduction of the UP, in addition to that obtained following CT, in particular, in MN patients in a severe nephrotic state.

Thr1313Met mutation in skeletal muscle sodium channels in a Japanese family with paramyotonia congenita

A 37-year-old Japanese woman was referred from another clinic to confirm the diagnosis of myotonia congenita. She had experienced cold-induced myotonia and muscle stiffness from early childhood. Of her three children, her elder son and her daughter have clinical features similar to hers. They experience neither grip nor percussion myotonia during warm weather, whereas myotonia is provoked by cold. Her younger son has no symptoms. DNA analyses of the SCN4A gene showed a C to T transition at nucleotide position 3938 in exon 22 of SCN4A (Thr1313Met) in all three affected family members, but not in the unaffected son. Paramyotonia congenita, the prevalence of which is very low in Japan, was diagnosed based on their clinical features and DNA analysis results.

Mature form of adrenomedullin is a useful marker to evaluate blood volume in hemodialysis patients

We investigated the pathophysiological significance of the mature form of adrenomedullin (AM) in hemodialysis (HD) patients. Thirty-nine HD patients were enrolled and divided into two groups: those undergoing ultrafiltration (UF) during an HD session, group I; and those not undergoing UF, group II. We measured mature AM, atrial natriuretic peptide (ANP), endothelin-1, nitric oxide, cyclic guanosine 3',5'-monophosphate, and catecholamine levels at 1-hour intervals during HD sessions. On-line optical measurement of hematocrit was used to estimate change in blood volume during HD. In group II, blood volume did not change significantly during HD, nor did plasma mature AM concentrations estimated at the beginning and end of the HD treatment (3.0 +/- 0.3 and 2.8 +/- 0.2 fmol/mL, respectively). However, blood volume decreased significantly in group I patients (-7.3% +/- 0.6%), as did plasma mature AM concentrations (from 4.4 +/- 0.3 to 3.1 +/- 0.3 fmol/mL; P < 0.01). In contrast to mature AM, plasma ANP concentrations declined in both groups (from 193 +/- 32 to 87 +/- 14 pg/mL in group I and 67 +/- 12 to 46 +/- 8 pg/mL in group II). We conclude that mature AM is a useful marker to evaluate circulating blood volume in HD patients. Circulating blood volume may regulate the conversion of AM from the inactive to the mature form.

A patient with myotonic dystrophy type 1 (DM 1) accompanied by laryngeal and renal cell carcinomas had a small CTG triplet repeat expansion but no somatic instability in normal tissues

We examined (CTG)n lengths in various tissues from a 70-year-old man with myotonic dystrophy type 1 (DM 1) who had a small 60-70 (CTG), expansion in his leukocytes. He died of renal cell carcinoma 5 years after a total laryngectomy for laryngeal carcinoma. Southern blot and polymerase chain reaction analyses were done on tissues obtained at autopsy. In the various normal tissues, (CTG). lengths were almost all the same size, whereas the renal cell carcinoma and metastatic tissues had longer lengths. When compared with the lengths in leukocytes about 5 years previously, (CTG)n lengths in the normal tissues were the same size. These findings suggest that both somatic instability and age-dependent (CTG). expansion in DM 1 patients with a small expansion may be less dominant than in patients with large expansions.