Clinical analysis of renoprotective responding patients administrated with oral adsorbent in chronic renal failure secondary to chronic glomerulonephritis

Pre-, pro-, and synbiotics: do they have a role in reducing uremic toxins? A systematic review and meta-analysis

Objective. This paper assessed the effectiveness of pre-, pro-, and synbiotics on reducing two protein-bound uremic toxins, p-cresyl sulphate (PCS) and indoxyl sulphate (IS). Methods. English language studies reporting serum, urinary, or fecal PCS and/or IS (or their precursors) following pre-, pro-, or synbiotic interventions (>1 day) in human adults were included. Population estimates of differences in the outcomes between the pre- and the postintervention were estimated for subgroups of studies using four meta-analyses. Quality was determined using the GRADE approach. Results. 19 studies met the inclusion criteria, 14 in healthy adults and five in haemodialysis patients. Eight studies investigated prebiotics, six probiotics, one synbiotics, one both pre- and probiotics, and three studies trialled all three interventions. The quality of the studies ranged from moderate to very low. 12 studies were included in the meta-analyses with all four meta-analyses reporting statistically significant reductions in IS and PCS with pre- and probiotic therapy. Conclusion. There is a limited but supportive evidence for the effectiveness of pre- and probiotics on reducing PCS and IS in the chronic kidney disease population. Further studies are needed to provide more definitive findings before routine clinical use can be recommended.

Usefulness of change in estimated glomerular filtration rate as a predicting factor of progression of chronic kidney disease

Purpose. To explore factors contributing to chronic kidney disease (CKD) progression and change in estimated glomerular filtration rate over time (ΔeGFR) as a risk factor in predialysis patients under multidisciplinary managements. Methods. Among 113 CKD patients, eGFR, serum creatinine, total protein, albumin, urea nitrogen, uric acid, calcium, inorganic phosphate, total cholesterol, urinary creatinine, urinary protein (UP), hemoglobin A1c, hemoglobin, and hematocrit were analyzed. Results. ΔeGFR analysis in the first six months presented a positive slope (remission group) in 43 patients (38%) and a negative slope (no-remission group) in 70 patients (62%). Three-year dialysis-free rate was 89.4% in the remission group and 39.3% in the no-remission group, with a significant difference (P < 0.0001). To explore factors contributing to dialysis initiation by stepwise Cox regression, baseline eGFR (HR 0.706, P < 0.0001) and ΔeGFR in the first six months of treatment (HR 0.075, P < 0.0001) were identified. To investigate factors affecting remission and no remission by stepwise logistic regression, age (odds ratio 1.06, P = 0.018) and UP excretion (odds ratio 1.223, P = 0.045) were identified. Conclusion. Monitoring of ΔeGFR and UP is not only useful in suppressing CKD 3 progression, but also in deciding strategies to achieve remission in individual patients.

Long-Term Effects of the Oral Adsorbent, AST-120, in Patients with Chronic Renal Failure

The oral adsorbent AST-120 has been widely used in Japan to delay the initiation of dialysis therapy in patients with chronic renal failure. This study evaluated the long-term effects of AST-120 in patients with chronic renal failure who had not previously undergone dialysis. One hundred out-patients were prospectively enrolled and prescribed 6 g/day oral AST-120 for ≥ 1 year. The clinical effectiveness of AST-120 was evaluated by comparing changes in the slope of the reciprocal serum creatinine-time plot (1/sCr slope) before and after AST-120 administration. The 1/sCr slope improved significantly after ≥ 1 year of AST-120 treatment and greatest improvement was observed in patients with the longest AST-120 administration period (> 30 months). The results suggest that long-term treatment with AST-120 may be beneficial for chronic renal failure patients in the pre-dialysis stage.

AST-120, an oral adsorbent, delays the initiation of dialysis in patients with chronic kidney diseases

The effects of an oral adsorbent, AST-120, in chronic kidney disease (CKD) patients was evaluated by the 24-month dialysis-free rate and 50% dialysis-free period. This study retrospectively analyzed 193 patients admitted to the Osaka Medical College Hospital between January 1994 and December 2001 because of CKD and who later started dialysis. The propensity score on multiple factors was used to match two groups of patients (AST-120 group, n = 78; non-AST-120 group, n = 78). Then, the proportion of patients remaining dialysis-free and the 50% dialysis-free period during the 24 months after starting treatment with or without AST-120 were analyzed. The impact of AST-120 on the risk of dialysis initiation was also determined by multivariate analysis. There were no significant differences in the clinical background and laboratory values after matching the two groups using the propensity score. The 50% dialysis-free period was significantly prolonged in the AST-120 group compared to the non-AST-120 group for all patients analyzed, as well as for the subgroup with diabetic or non-diabetic renal disease. When AST-120 treatment was started at a serum creatinine level below 3 mg/dL, the dialysis-free period was longer than 24 months in the AST-120 group, compared with 16.2 months in the non-AST-120 group. The 24-month dialysis-free rate was higher in the AST-120 group in every patient category. The risk of dialysis initiation was increased 3.48-fold in patients who were not administered AST-120. These results show that AST-120 delays the initiation of dialysis in CKD patients. Thus, AST-120 is an effective supplementary therapy to prevent the initiation of dialysis in CKD patients.

Prospective randomized study evaluating the efficacy of the spherical adsorptive carbon AST-120 in chronic kidney disease patients with moderate decrease in renal function

AIMS

We studied whether adding the spherical adsorptive carbon AST-120 to conventional treatments is effective in inhibiting progression of chronic kidney disease (CKD) at the stage of moderate decrease in renal function.

METHODS

43 CKD patients with moderately impaired renal function indicated by glomerular filtration rate (GFR) of 20-70 ml/min as measured by non-radiolabeled iothalamate clearance method were enrolled in the study. 26 patients showing a decrease of GFR by 5 ml/min during a 1-year observation period were randomized to receive ongoing treatments only (control group, 12 cases) or with AST-120 co-administered with ongoing treatment (AST-120 group, 14 cases). The intervention period was 1 year and the change in GFR was the primary evaluation variable.

RESULTS

The mean changes of GFR per month (DeltaGFR) in the intervention period were not significantly different between both groups. However, when comparing the DeltaGFR in the observation and intervention periods for each group, the rate of decline in GFR was significantly retarded (p < 0.001) in the AST-120 group while no significant difference was observed in the control group.

CONCLUSION

These results suggest that co-administration of AST-120 with conventional treatments retards decline in renal function in CKD patients with moderate decrease in renal function.

An oral adsorbent, AST-120, suppresses oxidative stress in uremic rats

BACKGROUND

The production of reactive oxygen species (ROS) has been suggested to play an important role in the progression of chronic kidney disease (CKD). An oral adsorbent, AST-120, removes uremic toxins such as indoxyl sulfate (IS) and delays the progression of CKD, but the effect on ROS production is unknown. The present study aimed to determine whether AST-120 reduces oxidative stress in uremic rat kidneys using markers of ROS production such as acrolein and 8-hydroxy-2'-deoxyguanosine (8-OHdG).

METHODS

Daily administration of AST-120 was started 6 weeks after 5/6 nephrectomy and continued for 18 weeks. The changes in metabolic data, serum and urine IS levels, urinary excretion of markers of oxidative stress, and renal histological findings were investigated in uremic rats with or without AST-120 treatment.

RESULTS

In parallel with the increase in serum and urine IS, the serum creatinine, urinary protein and acrolein levels started to increase at 6 weeks, but urinary 8-OHdG remained unchanged and significantly increased at 18 weeks in uremic rats. AST-120 markedly and significantly attenuated increases in uremic toxins and oxidative stress levels as well as the histological changes in glomerular sclerosis, interstitial fibrosis, and the tubular staining of 8-OHdG.

CONCLUSION

AST-120 suppressed the progression of CKD, at least in part, via attenuation of oxidative stress induced by uremic toxin.

Prognostic factors for a composite end-point of renal outcomes in patients with chronic kidney disease

We aimed to investigate prognostic factors for a composite end-point of end-stage renal disease (ESRD) and the progression of renal disease in Japanese patients with chronic renal disease. Using a composite end-point comprising a doubling of serum creatinine (sCr), an increase in sCr level to 6.0 mg/dL, or initiation of dialysis and renal transplantation caused by ESRD, we examined data obtained in a prospective cohort study. The present study consisted of 641 patients who were 20 years of age or older with chronic renal disease caused by diabetic nephropathy, glomerulonephritis, or nephrosclerosis, and who had baseline sCr levels of 5.0 mg/dL or less. The following criteria were examined as prognostic factors: sex; age; elapsed time from initial diagnosis; disease underlying the nephropathy (diabetic or non-diabetic); complications with hypertension, hyperlipidemia, or anemia; baseline sCr level; therapeutic regimen, including use of ACE inhibitors or Ca2+ -channel blockers; and diet. A log-rank test was used for univariate analysis, and Cox regression analysis was used for multivariate analysis. Underlying disease (diabetic or non-diabetic), baseline sCr level, and Ca2+ -channel blocker therapy were significantly related to event incidence. In the present study, we identified underlying disease and baseline sCr level as important prognostic factors for a composite end-point in a predialysis patient population in both the early and middle stages of renal disease. These factors should be considered as balancing variables for randomization in future clinical studies.

Protective effect of an oral adsorbent on renal function in chronic renal failure: determinants of its efficacy in diabetic nephropathy

Large-scale clinical trials have shown that the oral adsorbent AST-120 improves renal function and delays the initiation of dialysis in chronic renal failure (CRF) secondary to chronic glomerulonephritis. If renal failure progresses via common mechanisms, then the same effects can be expected in diabetic nephropathy. However, no study on diabetic nephropathy has been reported. Thus, we enrolled patients with statistically significant progression of CRF secondary to diabetic nephropathy, and analyzed the changes in renal function after AST-120 therapy, and the clinical factors associated with response to therapy. We enrolled 276 patients with diabetic nephropathy, whose serum creatinine (Scr) had increased from 3.4 to 4.5 mg/dL during the 4.5 +/- 3.7 months prior to the study. These patients took AST-120 at a dose of 5.0 +/- 1.4 g/day for 6 months. The clinical data were analyzed by dividing the patients into three groups based on the changes in Scr after AST-120 therapy, with responders showing a decrease (N = 82), partial responders showing <1.5-fold increase (N = 144), and non-responders showing >/=1.5-fold increase (N = 50). AST-120 significantly lowered the slope of 1/Scr-time line, suggesting that AST-120 suppressed the progression of renal impairment. No responders required dialysis, whereas 24.3% of the partial responders and 36.0% of the non-responders started dialysis therapy. In responders, the 1/Scr-time slope showed a negative-to-positive shift and serum urea nitrogen decreased significantly, whereas the improvement was moderate in partial responders and minimal in non-responders. Among responders, AST-120 therapy significantly improved renal function despite the presence of hypoproteinemia, hyperlipidemia, anemia or hypertension in many patients. The beneficial effect of AST-120 was significantly more marked in patients with blood pressure controlled within the normal ranges and hematocrit maintained at 30% or above. AST-120 reversed renal dysfunction or delayed the initiation of dialysis therapy in patients with progressive aggravation of CRF secondary to diabetic nephropathy, independent of hypoproteinemia, hyperlipidemia, anemia and hypertension. Active use of AST-120 may be recommended in patients with good control of blood pressure and hematocrit above 30%.

Oral Adsorbent AST-120 Decreases Carotid Intima-Media Thickness and Arterial Stiffness in Patients with Chronic Renal Failure

BACKGROUND/AIM

Intima media thickness (IMT) and stiffness of the carotid arteries is related to coronary artery disease, and chronic renal failure patients are at high risk for such diseases. An oral adsorbent, AST-120 (Kremezin; Kureha Chemical Industry, Tokyo, Japan), can delay the progression of chronic renal failure in undialyzed uremic patients. The aim of the present study was to determine whether AST-120 affects carotid artery IMT and pulse wave velocity (PWV) in patients with chronic renal failure not undergoing dialysis.

METHODS

Fifty patients with non-diabetic chronic renal failure were randomly divided into two groups: 30 patients (18 men and 12 women; mean age 53.5 years; mean serum creatinine 3.2 mg/dl) who were given AST-120 (6.0 g/day) and 20 patients (12 men and 8 women; mean age 52.0 years; mean serum creatinine 3.5 mg/dl) who were not given AST-120. Thirty healthy age-matched subjects (18 men and 12 women; mean age 51.5 years; mean serum creatinine 0.9 mg/dl) were also included. The treatment period was 24 months. IMT and arterial stiffness were measured before and after treatment.

RESULTS

The slope of the reciprocal serum creatinine concentration over time became significantly less steep in the AST-120 group than in the non-AST-120 group (p < 0.001). Before treatment, carotid artery IMT differed little between the AST-120 group (0.90 +/- 0.22 mm) and the non-AST-120 group (0.88 +/- 0.20 mm). IMT in these two groups was significantly greater than IMT in the control group (0.64 +/- 0.14 mm) (p < 0.01). Carotid IMT in the AST-120 group decreased slightly but not significantly to 0.84 +/- 0.20 mm after 12 months and then significantly after 24 months to 0.78 +/- 0.18 mm (p < 0.05). Carotid IMT in the non-AST group showed little change throughout the experimental period. PWV differed little between the AST-120 group (1,980 +/- 330 cm/s) and the non-AST group (1,940 +/- 360 cm/s) before treatment. PWV values in these two groups were significantly greater than PWV in the control group (1,280 +/- 240 cm/s) (p < 0.01). After 12 and 24 months, PWV in the AST-120 group decreased significantly to 1,840 +/- 280 cm/s (p < 0.05) and to 1,780 +/- 260 cm/s (p < 0.05), respectively; however, PWV in the non-AST group showed a slight increase during the experimental period.

CONCLUSION

The data suggest that AST-120 may reduce arterial stiffness and IMT in non-diabetic chronic renal failure patients before dialysis.