Patient knowledge and adherence to maintenance hemodialysis: an International comparison study.

BACKGROUND: Non-adherence to hemodialysis (HD) is associated with increased morbidity and mortality. In this cross-sectional study, we compared correlates and rates of non-adherence between the US and Japan to determine if differences in patient knowledge about HD might account for international variation in adherence. METHODS: We evaluated 100 US and 116 Japanese patients on maintenance HD. Patient knowledge was scored based on the identification of their vascular access, dry weight, cause of kidney disease, and ≥ 3 phosphorus- and potassium-rich foods. Patients were considered non-adherent if they missed > 3% of HD sessions in 3 months. RESULTS: 23% of the US and none of the Japanese patients were non-adherent. Using logistic regression, we found that in the US non-adherence was more common in black patients [Odds ratio (OR) 3.98; 95% confidence interval (CI) 1.42-11.22], while high school graduates (OR 0.20; 95% CI 0.05-0.81) and those on the transplant waiting list (OR 0.25; 95% CI 0.083-0.72) were less likely to miss their treatments. There was no significant association between knowledge and non-adherence in the US. However, Japanese patients had significantly higher levels of HD knowledge than US patients after adjusting for age (p < 0.001). CONCLUSION: Age-adjusted HD knowledge was higher and non-adherence rates were lower in Japan vs. the US. However, because of the unexpected finding of 100% adherence in Japan, we were unable to formally test whether knowledge was significantly associated with adherence across both countries. Further research is needed to understand the reasons behind the higher non-adherence rates in the US.

Dietary acid intake and kidney disease progression in the elderly.

BACKGROUND/AIMS: Non-volatile acid is produced by metabolism of organic sulfur in dietary protein, and promotes kidney damage. We investigated the role of dietary acid load, in terms of net endogenous acid production (NEAP), in chronic kidney disease (CKD) progression. METHODS: 217 CKD patients on low-protein diet with a normal serum bicarbonate level were enrolled in this retrospective cohort study in Japan. The primary outcome was 25% decline in estimated glomerular filtration rate (eGFR) or start of dialysis. Their NEAP was measured every 3 months. The patients were categorized into four groups on the basis of quartiles of NEAP every 3 months. The groups were treated as time-dependent variables. RESULTS: The average age (SD) was 70.6 (7.1) years; eGFR 23.5 (14.2) ml/min/1.73 m(2). Analysis using extended Cox models for the NEAP groups adjusted for baseline characteristics (referring to group 1 showing the lowest NEAP) showed that high NEAP was associated with a high risk of CKD progression; group 2, adjusted hazard ratio (HR) 3.930 (95% confidence interval (CI) 1.914, 8.072); group 3, adjusted HR 4.740 (95% CI 2.196, 10.288); group 4, adjusted HR 4.303 (95% CI 2.103, 8.805). Logistic regression analysis adjusted for baseline characteristics showed that the occurrence of hypoalbuminemia or hyperkalemia was associated with low serum bicarbonate level and the presence of complications at baseline, but not with NEAP. CONCLUSION: In elderly CKD patients, our findings suggest that high NEAP is independently associated with CKD progression. The decrease in NEAP may be an effective kidney-protective therapy.

High serum bicarbonate level within the normal range prevents the progression of chronic kidney disease in elderly chronic kidney disease patients.

BACKGROUND: Metabolic acidosis leads to chronic kidney disease (CKD) progression. The guidelines recommend a lower limit of serum bicarbonate level, but no upper limit. For serum bicarbonate level to be clinically useful as a therapeutic target marker, it is necessary to investigate the target serum bicarbonate level within the normal range to prevent CKD progression. METHODS: One hundred and thirteen elderly CKD patients, whose serum bicarbonate level was controlled within the normal range, were enrolled in this retrospective cohort study in Ibaraki, Japan. Outcome was defined as a decrease of 25% or more in estimated glomerular filtration rate (eGFR) or starting dialysis. We used Cox proportional hazard models adjusted for patients' characteristics to examine the association between serum bicarbonate level and the outcome. RESULTS: Female patients were 36.3%: average age (SD), 70.4 (6.6) years; eGFR, 25.7 (13.6) ml/min/1.73 m(2); serum bicarbonate level, 27.4 (3.2) mEq/l. Patients with the lowest quartile of serum bicarbonate levels [23.4 (1.8) mEq/l] showed a high risk of CKD progression compared with patients with high serum bicarbonate levels [28.8 (2.3) mEq/l]: adjusted hazard ratio (HR), 3.511 (95% CI, 1.342-9.186). A 1 mEq/l increase in serum bicarbonate level was associated with a low risk of CKD progression: adjusted HR, 0.791 [95% confidence interval (CI), 0.684-0.914]. CONCLUSIONS: In elderly CKD patients, our findings suggest that serum bicarbonate level is independently associated with CKD progression, and that a high serum bicarbonate level is associated with a low risk of CKD progression. A high target serum bicarbonate level within the normal range may be effective for preventing CKD progression.

Icodextrin reduces mortality and the drop-out rate in Japanese peritoneal dialysis patients.

Although numerous reports have shown that the use of icodextrin solution, as compared with conventional dextrose solutions, provides various clinical benefits, data on the impact of icodextrin solution on mortality and drop-out are sparse. In the present retrospective study, we compared clinical outcomes in a large cohort of patients prescribed either icodextrin or dextrose solution for the long dwell. A total of 7808 patients across Japan who were using Baxter peritoneal dialysis (PD) solutions in 2004 were included in this cross-sectional analysis. Outcomes data were retrieved from the Baxter Japan database. The annual drop-out rate in the icodextrin group (8.9%) was significantly (p < 0.0001) lower than that in the dextrose group (14.5%). The annual mortality rate was also lower (6.6% vs. 13.5%, p < 0.0001). Using data from the 2000 report of the Japanese Society for Dialysis Therapy, the relative risk of death in the icodextrin group, regardless of PD duration, was consistently lower than that in hemodialysis patients. These results indicate that, in PD, the use of icodextrin solution (as compared with dextrose solution) significantly reduces both mortality and drop-out rate.