Kiyoshi Kurokawa’s research while affiliated with National Graduate Institute for Policy Studies and other places

Background Socioeconomic status (SES) factors such as employment, educational attainment, income, and marital status can affect the health and well-being of the general population and have been associated with the prevalence of chronic kidney disease (CKD). However, no studies to date in Japan have reported on the prognosis of patients with CKD with respect to SES. This study aimed to investigate the influences of employment and education level on mortality and hospitalization among maintenance hemodialysis (HD) patients in Japan. Methods Data on 7974 HD patients enrolled in Dialysis Outcomes and Practice Patterns Study phases 1–4 (1999–2011) in Japan were analysed. Employment status, education level, demographic data, and comorbidities were abstracted at entry into DOPPS from patient records. Mortality and hospitalization events were collected during follow-up. Patients on dialysis < 120 days at study entry were excluded from the analyses. Cox regression modelled the association between employment and both mortality and hospitalization among patients < 60 years old. The association between education and outcomes was also assessed. The association between patient characteristics and employment among patients < 60 years old was assessed using logistic regression. Results During a median follow-up of 24.9 months (interquartile range, 18.4–32.0), 10% of patients died and 43% of patients had an inpatient hospitalization. Unemployment was associated with mortality (hazard ratio [HR] = 1.57; 95% confidence interval [CI]: 1.05–2.36) and hospitalization (HR = 1.25; 95% CI: 1.08–1.44). Compared to patients who graduated from university, patients with less than a high school (HS) education and patients who graduated HS with some college tended to have elevated mortality (HR = 1.41; 95% CI, 1.04–1.92 and HR = 1.36; 95% CI: 1.02–1.82, respectively) but were not at risk for increased hospitalizations. Factors associated with unemployment included lower level of education, older age, female gender, longer vintage, and several comorbidities. Conclusions Employment and education status were inversely associated with mortality in patients on maintenance HD in Japan. Employment but not education was also inversely associated with hospitalizations. After adjustment for comorbidities, the associations with clinical outcomes tended to be stronger for employment than education status.

To help relieve the burden of dietary restrictions experienced by many hemodialysis (HD) patients, dialysis staff may encourage patients, with no consideration to the degree of family support. Here, we clarified the effect of staff encouragement and living conditions on the burden of dietary restrictions in HD patients. This retrospective cohort study was conducted using data from the Dialysis Outcomes and Practice Patterns Study (DOPPS) I and III. We enrolled patients aged 18-75 years on HD therapy for at least 3 months. We categorized patients into four groups based on combinations of level of staff encouragement (high or low) and living condition (alone or with family) at baseline survey. Patients who felt they received high staff encouragement and lived with their family were set as the control. The main outcome was increase in patients' perceived burden of dietary restriction after 1 year. 1377 (69.1%) felt they received high staff encouragement, and 176 (9.1%) were living alone. After 1 year, 537 (26.9%) patients reported feeling an increased burden of dietary restriction. A low level of staff encouragement did not increase the burden in any patients, regardless of living situation. However, a high level of staff encouragement did increase the burden in patients living alone (adjusted odds ratio: 1.57, 95% confidence interval: 1.05-2.36). We observed an unexpected association between high staff encouragement and increased burden of dietary restriction among patients living alone. Staff encouragement may not relieve patients' burden with respect to dietary restriction and may in fact exacerbate it.

Cinacalcet lowers parathyroid hormone levels. Whether it can prolong survival of people with chronic kidney disease (CKD) complicated by secondary hyperparathyroidism (SHPT) remains controversial, in part because a recent randomized trial excluded patients with iPTH < 300 pg/ml. We examined cinacalcet's effects at different iPTH levels. This was a prospective case-cohort and cohort study involving 8229 patients with CKD stage 5D requiring maintenance hemodialysis who had SHPT. We studied relationships between cinacalcet initiation and important clinical outcomes. To avoid confounding by treatment selection, we used marginal structural models, adjusting for time-dependent confounders. Over a mean of 33 months, cinacalcet was more effective in patients with more severe SHPT. In patients with iPTH >= 500 pg/ml, the reduction in the risk of death from any cause was about 50% (Incidence Rate Ratio [IRR] = 0.49; 95% Confidence Interval [95% CI]: 0.29-0.82). For a composite of cardiovascular hospitalization and mortality, the association was not statistically significant, but the IRR was 0.67 (95% CI: 0.43-1.06). These findings indicate that decisions about using cinacalcet should take into account the severity of SHPT.

Background Dialysis guidelines in Japan recommend more frequent measurement of mineral metabolism markers than the Kidney Disease: Improving Global Outcomes guidelines. However, the extent to which frequent marker measurement contributes to achievement of target ranges and to therapy adjustment is unknown. Methods This multicenter cohort study involved 3276 hemodialysis patients with secondary hyperparathyroidism. Data on laboratory measurements and drug prescriptions were collected every 3 months. Main exposures were frequencies of measuring serum calcium and phosphorus [weekly/biweekly/monthly (reference)] and serum parathyroid hormone (PTH) [monthly/bimonthly/trimonthly (reference)] levels. Outcomes were achievement of guideline-specified ranges of mineral metabolism markers when serum levels were over, and maintenance of ranges when levels were already within, respective specified ranges, use of intravenous vitamin D receptor activator (VDRA) and initiation of cinacalcet use. Associations were examined via generalized estimating equations. Results When serum marker levels exceeded the target range, weekly measurement of calcium and phosphorus was positively associated with achievement of the guideline-specified calcium range [adjusted odds ratio (AOR): 1.57, 95% confidence interval (CI) 1.09–2.26] but not phosphorus range (AOR: 0.99, 95% CI 0.74–1.33). Monthly measurement of PTH was positively associated with achievement of the guideline-specified PTH range (AOR: 1.14, 95% CI 1.01–1.27). When serum marker levels were within the guideline-specified range, increased frequency of measurements was not associated with in-range maintenance of marker levels for any of the three mineral markers assessed. Regarding treatment regimen, relatively frequent measurement of serum calcium and phosphorus was positively associated with cinacalcet initiation and relatively frequent measurement of serum PTH with cinacalcet initiation and intravenous VDRA use. Conclusions Our results suggest that increasing frequency of measurements is helpful when serum marker levels exceed the target range, partially via adjustment in the therapeutic regimen. We found no evidence that frequent measurements are helpful when mineral levels are already within target ranges.

Background The extent of contribution of disturbed magnesium balance to mortality remains unclear among hemodialysis patients. Methods This was a cohort study involving 3276 patients on maintenance hemodialysis at 86 facilities in Japan from 2008 to 2010 who had secondary hyperparathyroidism (SHPT). Baseline serum magnesium (sMg) values were categorized into quintiles (≤2.3, >2.3–2.5, >2.5–2.7, >2.7–3.0 and >3.0 mg/dL), and the middle quintile was set as the reference. Outcome was all-cause death. Independent contribution to all-cause death was assessed via Cox regression to generate population-attributable fractions (PAFs). Results A total of 2165 patients from 68 facilities were analyzed. The lowest quintile of sMg was positively associated with lower serum potassium and albumin levels, higher C-reactive protein (CRP) levels and prevalence of atrial fibrillation and cerebrovascular disease than the other quintiles. The highest sMg quintile was positively associated with higher potassium levels, and negatively associated with lower serum albumin levels and higher intact parathyroid hormone and CRP levels and prevalence of cerebrovascular disease than the other quintiles. During a median follow-up of 3 years, the lowest and the second lowest quintiles of sMg were associated with all-cause death [adjusted hazard ratio (HR) 1.737, 95% confidence interval (95% CI) 1.200–2.512 and HR 1.675, 95% CI 1.254–2.238, respectively). Point estimates of adjusted HRs of the highest and the second highest sMg quintiles were higher than those of the middle quintile for all-cause death. Adjusted PAFs of lower sMg and of higher and lower sMg for all-cause death were 24.0% (95% CI 13.0–35.0%) and 30.7% (95% CI 14.5–46.8%), respectively. Conclusion In hemodialysis patients with SHPT, dysregulated sMg is an important contributor to all-cause death. Further studies are warranted to examine whether or not correction of sMg improves survival.

Introduction and Aims: On-line dialysance (Kt) and thermodilution (BTM-Qa) methods could be important components in vascular access monitoring programs. This study evaluated the efficiency of these two methods in reducing the thrombosis rate and access-related costs compared with a historic control group. Methods: We studied 148 long-term hemodialysis patients with arteriovenous fistulas (historical control group, n = 74) for 2 years. During the study period, the indications for vascular treatments were the Kt reduction ≥20% with respect to baseline values or Qa less than 500 mL/min (or a decrease in flow > 20%). Differences between the Qa and Kt groups were tested using Student’s T-Test or the Wilcoxon test, as appropriate. The χ2 test was used to analyze the angioplasty and thrombosis rates compared with the historical control group. A P-value ≤0.05 was considered statistically significant. Results: During the study period, we detected 16 cases of significant vascular access dysfunction. The Kt value after vascular treatment was 71.1L (59L; P = 0.001) and BTM-Qa was 1218.6 mL/min (519.7 mL/min; P = 0.001). Compared with the control group, the thrombosis rate was 0.027 vs 0.148 episodes/patient-year (P = 0.009) and the total access-related cost was €22,293 vs €47,467 (P = 0.033). Conclusions: This study suggests that a combined monitoring program based on Kt and Qa-BTM represents an effective screening method that significantly reduces the thrombosis rate and economic costs of vascular treatments View larger version: In this window In a new window Download as PowerPoint Slide