Effect of Nonsupplemented Low-Protein Diet on the Initiation of Renal Replacement Therapy in Stage 4 and 5 Chronic Kidney Disease: A Retrospective Multicenter Cohort Study in Japan.

OBJECTIVE: In subjects with chronic kidney disease (CKD), the effect of low-protein diet (LPD) is expected to alleviate uremic symptoms. However, whether LPD is effective in preventing loss of kidney function is controversial. The aim of this study was to evaluate the association between LPD and renal outcomes. METHODS: We conducted a multicenter cohort study of 325 patients who suffered CKD stage 4 and 5 with eGFR ≥10 mL/min/1.73 m,2 between January 2008 and December 2014. The primary diseases of the patients were chronic glomerulonephritis (47.7%), nephrosclerosis (16.9%), diabetic nephropathy (26.2%), and others (9.2%). The patients were divided into four groups, based on the mean protein intake (PI)/day, group 1 (n = 76): PI < 0.5 g/kg ideal body weight/day, group 2 (n = 56): 0.5 ≤ PI < 0.6 g/kg/day, group 3 (n = 110): 0.6 ≤ PI < 0.8 g/kg/day, group 4 (n = 83): PI ≥ 0.8 g/kg/day. Dietary supplementation with essential amino acids and ketoanalogues was not used. The outcome measure was occurrence of renal replacement therapy (RRT) (hemodialysis, peritoneal dialysis, renal transplantation (excluding preemptive transplantation)) and all-cause mortality until December 2018. Cox regression models were used to examine whether LPD was associated with the risk of outcomes. RESULTS: During a mean follow-up of 4.1 ± 2.2 years. Thirty-three patients (10.2%) died of all causes, 163 patients (50.2%) needed to start RRT, and 6 patients (1.8%) received a renal transplant. LPD therapy of 0.5 g/kg/day or less was significantly related to a lower risk of RRT and all-cause mortality [Hazard ratio = 0.656; 95% confidence interval, 0.438 to 0.984, P = .042]. CONCLUSIONS: These results suggest that non-supplemented LPD therapy of 0.5 g/kg/day or less may prolong the initiation of RRT in stage 4 and 5 CKD patients.

Intravenous Maxacalcitol Therapy Correlates with Serum Fibroblast Growth Factor 23 Levels in Hemodialysis Patients Independent of Serum Phosphate or Calcium Levels.

Fibroblast growth factor 23 (FGF23) is a regulator of phosphate and vitamin D homeostasis that carries out primary bone- and mineral-related physiological functions to increase renal phosphate excretion and reduce 1α-hydroxylation of 25-hydroxyvitamin D. In a negative endocrine feedback loop, 1,25-dihydroxyvitamin D also stimulates FGF23 secretion. Previous studies have assessed the correlation between vitamin D receptor activator therapy and FGF23 concentrations, and to our knowledge, none has assessed the correlation between intravenous (i.v.) maxacalcitol therapy and FGF23 concentration in hemodialysis patients. Subjects included 148 patients on maintenance hemodialysis. Serum FGF23 concentrations were measured. The correlations among serum FGF23 concentrations with i.v. maxacalcitol therapy and other clinical parameters and medications were analyzed. Mean serum log FGF23 was 3.7 ± 0.8 pg/mL. After division into two equal groups based on median serum log FGF23 level, the percentages of patients administered i.v. maxacalcitol (60/74 [81.1%] vs. 45/74 [60.8%], p < 0.01) were significantly higher in the high log FGF23 group. The amounts of serum FGF23 concentrations had been significantly higher to the amounts of i.v. maxacalcitol per week dependency. Multivariate regression analysis showed that treatment with i.v. maxacalcitol was an independent predictor of serum FGF23 levels, regardless of phosphate or calcium concentrations. i.v. maxacalcitol correlates with serum FGF23 concentration in hemodialysis patients, independent of serum phosphate or calcium concentrations.

Vascular calcification estimated by aortic calcification area index is a significant predictive parameter of cardiovascular mortality in hemodialysis patients.

BACKGROUND: Vascular calcification is a feature of arteriosclerosis. In hemodialysis (HD) patients, vascular calcification progresses rapidly. This study used the aortic calcification area index (ACAI), an index of vascular calcification, to evaluate vascular calcification factors in HD patients, to investigate correlations between ACAI and long-term prognosis and to assess correlations between various factors and long-term prognosis. METHODS: Subjects comprised 137 patients on maintenance HD. ACAI was measured as an index of vascular calcification as measured by abdominal plain computed tomography. The patients were divided into a high ACAI (H) group and a low ACAI (L) group according to whether the ACAI was below or above the mean value (21.4%) of ACAI, and long-term all-cause death and cardiovascular death rates were compared between groups. Risk factors for all-cause death and cardiovascular death were examined by Cox hazard analysis. RESULTS: During follow-up (mean follow-up period 95.3 ± 50.3 months), 76 patients died, including 46 cardiovascular deaths. Deaths included 51 of 70 patients (67.1%) in Group H and 25 of 67 patients (37.3%) in Group L. Cardiovascular death rates were 51.4 and 14.9%, respectively. On Kaplan-Meier analysis, the number of all-cause deaths was significantly higher in Group H (P < 0.001, log-rank test). Similarly, the number of cardiovascular deaths was significantly higher in Group H. Multivariate Cox proportional hazards analysis showed that ACAI (%) was a significant prognostic indicator for cardiovascular death (hazard ratio 1.03; 95% confidence interval 1.00-1.06, P = 0.03). CONCLUSION: High ACAI was clearly correlated with mortality rate in HD patients, particularly cardiovascular mortality rate. ACAI was a useful long-term prognostic indicator in HD patients.

Improved assessment of aortic calcification in Japanese patients undergoing maintenance hemodialysis.

OBJECTIVE: Vascular calcification is a feature of arteriosclerosis and in hemodialysis (HD) patients it may be severe, even at a relatively young age, and is closely related to the overall prognosis. We used the aortic calcification area index (ACAI), derived from the aortic calcification index (ACI), to evaluate and analyze the risk factors for abdominal aortic calcification in HD patients. PATIENTS AND METHODS: Subjects comprised 137 patients on maintenance HD. ACAI was measured on abdominal plain computed tomography: 10 slices of the abdominal aorta were obtained at 1-cm intervals from the bifurcation of the common iliac artery and the area of the aortic cross-section and calcification was measured using image software. The calcification area was divided by the cross-sectional area and expressed as a percentage (%). The mean value for the 10 slices was also calculated. Patients were divided into 2 groups according to ACAI being lower or higher than the mean value and the risk factors in each group were compared by multivariate analysis. Results Group comparison showed significant differences in age, systolic blood pressure, serum calcium, and lipoprotein(a). On multiple regression analysis, age, systolic blood pressure, and serum calcium were independent risk factors. On logistic regression analysis, age, duration of dialysis, systolic blood pressure, and serum calcium were independent risk factors. CONCLUSION: Risk factors for abdominal aortic calcification in HD patients include age, systolic blood pressure, and serum calcium, according to ACAI evaluation. The ACAI was accurate and useful for evaluating abdominal calcification.

[Long-term suppressive effect of falecalcitriol on parathyroid hormone secretion in secondary hyperparathyroidism in hemodialysis patients].

Alfacarcidol and calcitriol are widely used to treat secondary hyperparathyroidism associated with chronic renal failure, but it is often not possible to administer doses high enough to sufficiently inhibit parathyroid hormones because of the risk of hypercalcemia and hyperphosphatemia. We administered falecalcitriol (Hornel) Tablets) to patients with poorly controlled secondary hyperparathyroidism. The usefulness of falecalcitriol was demonstrated by the fact that control of intact-PTH was maintained for up to 24 months without a clear increase in serum Ca x serum inorganic phosphorus (iP), iP, and ALP levels.

[Levels of serum ascorbate and its metabolites in hemodialysis patients].

The status of ascorbic acid (AA) in dialysis patients is the subject of debate. Some reports have found AA to be deficient in dialysis patients, while others have found that AA is not deficient. In an attempt to confirm AA serum concentrations in dialysis patients, we analyzed the concentrations of AA as well as its metabolites using the specific determination of AA with chemical derivatization and the HPLC method. We studied 131 patients under maintenance hemodialysis therapy (HD), 23 patients with chronic renal failure (CRF) and 48 healthy controls (C). Serum concentrations of AA and the AA metabolites dehydroascorbic acid (DHA) and 2, 3-diketogulonate (DKG) were measured by HPLC. Nine HD patients were taking AA supplements. Seventy-six (62.3%) of the 122 HD patients not taking AA supplements exhibited deficient levels of AA (< 20 microM), while 13 (56.5%) of the 23 CRF patients and 9 (18.8%) of the 48 C showed deficient levels of AA. Analysis of AA metabolites in the normal-range AA (20-80 microM) group revealed that the DHA/AA ratio in HD patients was significantly higher than in C (3.3 +/- 2.6% and 1.2 +/- 2.2%, respectively). The DKG/AA ratio in HD patients was higher than in CRF patients (3.6 +/- 5.2% vs. 0.9 +/- 1.9%), whereas DKG was not detected in C. When compared to serum levels before the start of dialysis, serum AA, DHA and DKG concentrations at the end of the dialysis session decreased by an average of 74.2, 84.0 and 78.8% respectively. In HD patients, serum levels of thiobarbituric reactive substances (TBARS) were significantly lower in the higher AA (> 80 microM) group than in the deficient and normal-range AA groups. In 12 AA-deficient patients, after 1 month of taking AA supplements (200 mg/day), serum AA levels rose to 79.9 microM, while serum TBARS level declined when compared with levels before supplementation. In conclusion, the frequency of AA deficiency in dialysis patients is extremely high. AA deficiency in HD patients may result in high TBARS levels, which reflect increased oxidative stress. Adequate AA supplementation should therefore be considered in such patients.