New-Onset Anemia and Associated Risk of ESKD and Death in Non-Dialysis CKD Patients: A Multi-Cohort Observational Study

Background

Anemia is a common complication of chronic kidney disease (CKD), but its incidence in nephrology settings is poorly investigated. Similarly, the risks of adverse outcomes associated with new-onset anemia are not known.

Methods

We performed a pooled analysis of three observational cohort studies including 1031 non-anemic CKD patients with eGFR <60 mL/min/1.73 m² regularly followed in renal clinics. We estimated the incidence of mild anemia (hemoglobin 11–12 g/dL in women and 11–13 g/dL in men) and severe anemia (hemoglobin <11 g/dL or use of erythropoiesis-stimulating agents) during a 3-year follow-up period. Thereafter we estimated the risk of end-stage kidney disease (ESKD) and all-cause death associated with new-onset mild and severe anemia.

Results

The mean age was 63 ± 14 years, 60% were men and 20% had diabetes. The mean estimated glomerular filtration rate (eGFR) was 37 ± 13 mL/min/1.73 m² and the median proteinuria was 0.4 g/day [interquartile range (IQR) 0.1–1.1]. The incidence of mild and severe anemia was 13.7/100 patients-year and 6.2/100 patients-year, respectively. Basal predictors of either mild or severe anemia were diabetes, lower hemoglobin, higher serum phosphate, eGFR <30 mL/min/1.73 m² and proteinuria >0.50 g/day. Male sex, moderate CKD (eGFR 30–44 mL/min/1.73 m²) and moderate proteinuria (0.15–0.50 g/day) predicted only mild anemia. The incidence of anemia increased progressively with CKD stages (from 8.77 to 76.59/100 patients-year) and the proteinuria category (from 13.99 to 25.02/100 patients-year). During a median follow-up of 3.1 years, 232 patients reached ESKD and 135 died. Compared with non-anemic patients, mild anemia was associated with a higher adjusted risk of ESKD {hazard ratio [HR] 1.42 [95% confidence interval (CI) 1.02–1.98]} and all-cause death [HR 1.55 (95% CI 1.04–2.32)]. Severe anemia was associated with an even higher risk of ESKD [HR 1.73 (95% CI 1.20–2.51)] and death [HR 1.83 (95% CI 1.05–3.19)].

Conclusions

New-onset anemia is frequent, particularly in patients with more severe renal damage and in those with diabetes mellitus. The occurrence of anemia, even of a mild degree, is associated with mortality risk and faster progression towards ESKD.

[Calcific uremic arteriolopathy (Calcyphilaxis): a rare disease? Report of three cases]

INTRODUCTION

Calcific uremic arteriolopathy (CUA; CALCYPHILAXIS) is a syndrome that occurs prevalently in patients with chronic kidney disease on dialysis. It is characterized by the medial calcification of skin small arteries leading to necrotic lesions. Several risk factors have been identified: obesity, female gender, diabetes mellitus, hyperphosphatemia, inflammation, treatment with vitamin D, calcium-based phosphate binders and warfarin.

MATERIALS AND METHODS

We report three cases of CUA observed from October 2011 to September 2014.

RESULTS

The mean age at diagnosis was 56 years (range 33-68). Biochemistry showed: mean levels of PTH=1277 pg/ml (range 1000-1696), serum calcium =10.2 mg/dl (range 9.4-11.1), phosphorus=4.5 mg/dl (range 3.4-5.5). All patients were taking vitamin D, two patients were on warfarin therapy. Following actions were undertaken: interruption of calcium-based phosphate binders, vitamin D and warfarin therapy, initiation of cinacalcet and sodium thiosulfate therapy, use of dialysate with lowest available calcium concentration (1.25 mmol/l), Hyperbaric Oxygen Therapy, surgical dressings of skin lesions three times a week. Significant improvement was observed in mean levels of PTH (331 pg/ml, range 200-465), serum calcium (8.3 mg/dl, range 7.4-9.6) and phosphorus (3.4 mg/dl, range 2.6-3.8). In two out of three patients complete healing of ulcerative lesions was obtained.

CONCLUSIONS

These cases underline the importance of early diagnosis of CUA especially in patients with concomitant risk factors and careful clinical monitoring, being CUA characterized by a rapid evolution and high mortality.

Plasma p-cresol lowering effect of sevelamer in peritoneal dialysis patients: evidence from a Cross-Sectional Observational Study

p-Cresol is a by-product of the metabolism of aromatic aminoacid operated by resident intestinal bacteria. In patients with chronic kidney disease, the accumulation of p-cresol and of its metabolite p-cresyl-sulphate causes endothelial dysfunction and ultimately increases the cardiovascular risk of these patients. Therapeutic strategies to reduce plasma p-cresol levels are highly demanded but not available yet. Because it has been reported that the phosphate binder sevelamer sequesters p-cresol in vitro we hypothesized that it could do so also in peritoneal dialysis patients. To explore this hypothesis we measured total cresol plasma concentrations in 57 patients with end-stage renal disease on peritoneal dialysis, 29 receiving sevelamer for the treatment of hyperphosphatemia and 28 patients not assuming this drug. Among the patients not assuming sevelamer, 16 were treated with lanthanum whereas the remaining 12 received no drug because they were not hyperphosphatemic. Patients receiving sevelamer had plasma p-cresol and serum high sensitivity C-reactive protein concentrations significantly lower than those receiving lanthanum or no drug. Conversely, no difference was observed among the different groups either in residual glomerular filtration rate, total weekly dialysis dose, total clearance, urine volume, protein catabolic rate, serum albumin or serum phosphate levels. Multiple linear regression analysis showed that none of these variables predicted plasma p-cresol concentrations that, instead, negatively correlated with the use of sevelamer. These results suggest that sevelamer could be an effective strategy to lower p-cresol circulating levels in peritoneal dialysis patients in which it could also favorably affect cardiovascular risk because of its anti-inflammatory effect.

Blood pressure variability and outcomes in chronic kidney disease

BACKGROUND

We investigated the effects of visit-to-visit systolic blood pressure variability (SBPV) on both mortality and dialysis inception in a cohort of chronic kidney disease (CKD) patients not requiring dialysis therapy. Furthermore, we also explored the carry-over effect of visit-to-visit SBPV on mortality after dialysis initiation.

METHODS

We conducted a longitudinal retrospective, observational, multi-centre study in three tertiary care nephrology outpatient clinics. All the ambulatory CKD patients admitted to the outpatient clinics from 1 January 2004 to 31 December 2005 were screened for study eligibility. We selected all consecutive patients older than 18 years of age with a mean estimated glomerular filtration rate of <60 mL/min/m(2), free from cardiovascular disease. SBPV was defined as the ratio of the SD to the mean SBP of five values recorded during a run-in phase of 4-5 months. Data on dialysis inception and mortality were recorded through 31 December 2010.

RESULTS

Overall, we selected a cohort of 374 elderly (median age: 79 years) subjects. A total of 232 (62%) and 103 (29%) patients were male and had diabetes, respectively. A significant association between SBPV and the risk of death but not of CKD progression to dialysis was noted at univariate and after multivariable adjustments (hazard ratio for all-cause mortality per 1% increase in SBPV: 1.05; 95% confidence interval: 1.02-1.09; P = 0.001). Notably, no lethal event was recorded after dialysis initiation.

CONCLUSIONS

Current findings suggest that SBPV may be of use for risk stratification in CKD patients.

Progression of coronary artery calcification and cardiac events in patients with chronic renal disease not receiving dialysis

We tested for the presence of coronary calcifications in patients with chronic renal disease not on dialysis and studied its progression in 181 consecutive non-dialyzed patients who were followed for a median of 745 days. Coronary calcifications (calcium score) were tallied in Agatston units by computed tomography, and the patients were stratified into two groups by their baseline calcium score (100 U or less and over 100 U). Survival was measured by baseline calcium score and its progression. Cardiac death and myocardial infarction occurred in 29 patients and were significantly more frequent in those patients with calcium scores over 100 U (hazard ratio of 4.11). With a calcium score of 100 U or less, the hazard ratio for cardiac events was 0.41 and 3.26 in patients with absent and accelerated progression, respectively. Thus, in non-dialyzed patients, the extent of coronary calcifications was associated to cardiac events, and progression was an independent predictive factor of cardiac events mainly in less calcified patients. Hence, assessment of coronary calcifications and progression might be useful for earlier management of risk factors and guiding decisions for prevention of cardiac events in this patient population.

Effect of a low- versus moderate-protein diet on progression of CKD: follow-up of a randomized controlled trial

BACKGROUND

Whether low-protein-diet (LPD) as opposed to moderate-protein-diet (MPD) regimens improve the long-term survival of patients with chronic kidney disease (CKD) or induce protein-caloric malnutrition is unknown.

STUDY DESIGN

Intention-to-treat analysis of follow-up data from a randomized controlled trial.

SETTING & PARTICIPANTS

423 patients with CKD (stages 4-5) were randomly assigned between January 1999 and January 2003 and followed up until December 2006 or death. The first phase of follow up was from January 1999 to June 2004; additional follow-up was from July 2004 to December 2006.

INTERVENTION

LPD versus MPD (protein intake, 0.55 vs 0.80 g/kg/d).

OUTCOMES

Protein-caloric malnutrition (defined as the occurrence of 1 of the following: loss of body weight > 5% in 1 month or 7.5% in 3 months or body mass index < 20 kg/m(2) with serum albumin level < 3.2 g/dL and normal C-reactive protein level [<0.5 mg/dL]), dialysis, death, or the composite outcome of dialysis and death.

RESULTS

Baseline mean age was 61 years, estimated glomerular filtration rate was 16 mL/min/1.73 m(2), proteinuria had protein excretion of 1.67 g/d, body mass index was 27.1 kg/m(2), protein intake was 0.95 g/kg/d, and there were 57% men. Duration of follow-up was 32 months (median, 30 months; 25th-75th percentiles, 21-39). Average protein intakes were 0.73 +/- 0.04 g/kg/d for the LPD and 0.9 +/- 0.06 g/kg/d for the MPD. 3 patients (0.7%) met criteria for protein-caloric malnutrition. 48 patients died (11%), 83 initiated dialysis therapy (20%), and 113 (27%) reached the composite outcome. In unadjusted Cox survival analyses, effects of the LPD on these outcomes were 1.01 (95% CI, 0.57-1.79), 0.96 (95% CI, 0.62-1.48), and 0.98 (95% CI, 0.68-1.42), respectively.

LIMITATIONS

Low event rates for dialysis therapy initiation and death.

CONCLUSIONS

Most patients, who were regularly followed up in CKD clinics, were acceptably adherent to the prescribed dietary protein intake restrictions; the LPD and MPD did not lead to protein wasting; and the LPD did not decrease the risk of death or dialysis therapy initiation compared with the MPD.

Epoetin therapy and hemoglobin level variability in nondialysis patients with chronic kidney disease

BACKGROUND AND OBJECTIVES

Intrapatient variability of hemoglobin (Hb) is a newly proposed determinant of adverse outcome in chronic kidney disease (CKD). We evaluated whether intensity of epoetin therapy affects Hb variability and renal survival in nondialysis CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We calculated the individual therapeutic index (TI) for epoetin (EPO; difference between rates of visits that required EPO dosage change and those with effective EPO change) from 1198 visits during the first year of EPO in 137 patients. Renal death was registered in the subsequent 18.1 mo. Analysis was made by TI tertile (lower, middle, and higher; i.e., from more to less intensive therapy).

RESULTS

Main features and visit number were similar in tertiles. Lower Hb response to first EPO dosage was an independent predictor of higher TI (P = 0.002). The area under the curve for Hb (11.56 +/- 0.87, 11.46 +/- 1.20, and 10.95 +/- 1.48 g/dl per yr; P = 0.040) decreased from lower to higher tertile. Hb variability increased in parallel, as shown by the reduction of time with Hb at target (time in target, from 9.2 +/- 2.0 to 3.0 +/- 2.2 mo; P < 0.0001) and the wider values of within-patient Hb standard deviation (from 0.70 to 0.96; P = 0.005) and Hb fluctuations across target (P < 0.0001). In Cox analyses (hazard ratio [95% confidence interval]), risk for renal death was increased in the middle and higher tertiles (2.79 [1.36 to 5.73] and 2.94 [1.40 to 6.20]) and reduced by longer time in target (0.90 [0.83 to 0.98]).

CONCLUSIONS

Lack of adjustment of EPO worsens Hb variability in CKD. Hb variability may be associated with renal survival, but further studies are needed to explore the association versus causal relationship.

Beneficial effects of better control of secondary hyperparathyroidism with paricalcitol in chronic dialysis patients

BACKGROUND

Treatment of secondary hyperparathyroidism (SHPT) with calcitriol is often limited by the occurrence of hypercalcemia, hyperphosphatemia and risk of vascular calcifications. Paricalcitol, a vitamin D analogue with lower calcemic and phosphatemic effects, is successfully utilized in dialysis patients, although some uncertainty remains about the optimal dosage. Amelioration of survival in hemodialysis patients has been correlated to the use of calcitriol and, even better, paricalcitol.

METHODS

We evaluated 1-year treatment with paricalcitol in 12 chronic hemodialysis patients with moderate-severe SHPT previously treated with intravenous calcitriol. Starting dose of paricalcitol was calculated according to the severity of the disease by the formula: intact parathyroid hormone (iPTH)/80, and successive titration performed according to the NKF-DOQI guidelines.

RESULTS

Paricalcitol caused a rapid decrease in serum levels of iPTH with a consistent percentage of values falling below 150 pg/mL in the first months of treatment. Although the occurrence of hypercalcemia was not significantly different between treatment with calcitriol and paricalcitol, a slight but significant increase in mean calcium levels was observed during paricalcitol treatment. A significant amelioration of erythropoiesis and acid-base balance was observed during paricalcitol treatment.

CONCLUSIONS

Paricalcitol efficiently suppresses PTH secretion in dialysis patients with SHPT, with a moderate calcemic, but not a phosphatemic, effect. The dose of paricalcitol calculated as iPTH/80 may cause acute lowering of bone turnover. The improvement of anemia control and the amelioration of acid-base balance are 2 important additive effects of the better control of SHPT that may improve survival of hemodialysis patients.

Sleep quality in patients with chronic renal failure: A 3-year longitudinal study

BACKGROUND

Despite the high prevalence of sleep disorders in patients with kidney disease, no relationship has been demonstrated between sleep quality and the degree of renal function in cross-sectional studies. A prospective trial was, therefore, started in patients with chronic renal failure (CRF) to evaluate whether a link exists between the modifications of these parameters observed during a three-year follow-up period.

METHODS

Sleep quality was determined by the Pittsburgh Sleep Quality Index (PSQI) at baseline and after two and three years (Time 0, 2 and 3, respectively) in 78 patients with various degrees of CRF in association with the main clinical and biochemical variables.

RESULTS

The baseline PSQI averaged 6.2+/-3.8 (range: 0-21, with higher values indicating worse sleep quality) and was significantly increased at both Time 2 and 3 (8.8+/-3.7 and 10.2+/-3.5, respectively, P<0.0001 vs baseline), whereas creatinine clearance progressively decreased (45+/-24 vs 41+/-26 and 32+/-20ml/min, at time 0, 2 and 3, respectively, P<0.0001), although an independent association with PSQI could not be demonstrated after adjustment for confounding factors (P=0.90, mixed linear model).

CONCLUSIONS

Our data suggest that the progression of renal disease is accompanied by a progressive worsening of sleep quality; age is strongly related to both phenomena. PSQI represents an easy tool to use to detect sleep disorders and to more effectively evaluate renal patients; the prevention of sleep disorders by early and appropriate treatments could beneficially influence the course of the disease.

Stability of target hemoglobin levels during the first year of epoetin treatment in patients with chronic kidney disease

BACKGROUND AND OBJECTIVES

Instability of hemoglobin levels during epoetin therapy is a new problem in hemodialysis. We evaluated extent and correlates of time in target, that is, the time spent with hemoglobin > or = 11 g/dl during the first year of epoetin and its association with renal survival.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were collected in 917 visits for 12.0 mo in 119 patients with chronic kidney disease; thereafter, patients started renal survival analysis for 10.1 mo. At baseline, hemoglobin was 10.0 +/- 0.8 g/dl and GFR was 22.1 +/- 14.2 ml/min per 1.73 m2.

RESULTS

Hemoglobin target, reached in 1.5 mo, was steadily maintained in only 24% of patients. Time in target was not merely due to differences in time to target; after first achievement of target, in fact, a reduction of hemoglobin < 11 g/dl occurred in 51% of patients. At multivariate analysis, male gender, basal GFR and hemoglobin levels, first epoetin dose, and iron supplementation were directly associated with length of time in target. A lower risk for renal death (dialysis n = 53; death n = 8) was detected in the higher tertile of time in target (11.3 mo) versus lower tertile (3.2 mo). This difference persisted at Cox analysis after adjustment for age, gender, GFR, BP, and proteinuria.

CONCLUSIONS

In chronic kidney disease, time in target during the first year of epoetin therapy is frequently short depending not only on time to target but also on post-target hemoglobin reductions, correlates with male gender, timing, and intensity of initial therapy and is coupled with better renal survival.

Hepatitis C and kidney disease

Hepatitis C virus (HCV) infection is often associated with kidney diseases such as membranoproliferative glomerulonephritis (MPGN), with and without cryoglobulinemia, membranous glomerulonephritis (MGN) or glomerulosclerosis (FSGN). The aim of our study was to determine the frequency of HCV with or without hypertransaminasemia in patients with chronic nephropathy in the predialytic phase. We tested 340 subjects with chronic renal insufficiency (CRI) from our hospital's nephrology outpatient clinic for anti-HCV antibodies. In positive subjects we tested for HCV RNA by PCR method, monitoring, for at least 4 months, common biohumoral parameters including transaminases (AST, ALT). Of the 340 subjects, 46 (13.5%) were positive for HCV RNA, and 8 of these (17%) showed constant alteration of transaminases. HBsAg was found in 8 of the total study population (2.3%), and none of these showed altered transaminases. Type II diabetes mellitus was found in 26% (12/46) of the HCV-RNA positive patients, and in only 12.5% (37/294) of the negative ones. The kidney diseases we found in the 46 HCV-RNA positive patients were: diabetic nephropathy in 11 (23.9%), MPGN in 7 (15.2%), MPGN + cryoglobulinemia in 2 (4.3%), interstitial nephropathy in 4 (8.7%), IgA mesangial GN in 3 (6.5%), hypertensive nephropathy in 2 (4.3%), focal and segmental GN in 1 (2.2%), urologic disease in 4 (8.7%), other (hematological, genetic, iatrogenic) in 3 (6.6%), unknown in 9 (19.6%). Our data show that the most frequent kidney diseases associated with HCV infection were diabetic related nephropathy and MPGN with and without cryoglobulinemia. HCV infection had a positive association with diabetes. It is interesting to note that in this study population the hepatitis C concomitant to kidney disease was unusually mild: only 4 of the 46 subjects (9%) showed clinical, biohumoral and ultrasound evidence of cirrhosis.

Management of cardiovascular risk factors in advanced type 2 diabetic nephropathy: a comparative analysis in nephrology, diabetology and primary care settings

OBJECTIVES

Advanced diabetic nephropathy (DN) is characterized by a marked development of cardiovascular and renal disease. These patients are frequently managed by different health professionals with the consequence that the quality of care may differ substantially. To compare the management of cardiovascular risk factors in patients with type 2 DN and an estimated glomerular filtration rate (GFR) of 15-60 ml/min per 1.73 m2 followed in nephrology, diabetology and primary care.

METHODS

This multicentre cross-sectional study verified the control of blood pressure (BP), total cholesterol, triglycerides, glycosylated haemoglobin A1c (HbA1c) and haemoglobin in patients exclusively followed in either nephrology (n = 266), diabetology (n = 246) or primary care (n = 195) of the same metropolitan area for at least 1 year.

RESULTS

Primary care patients were older and had a greater prevalence of previous cardiovascular events. The GFR was lower in nephrology than in diabetology and primary care (33 +/- 13 versus 47 +/- 9 and 40 +/- 12 ml/min per 1.73 m2, P < 0.0001). The prevalence of BP target (< 130/80 mmHg) was similarly low in nephrology, diabetology and primary care (14, 13 and 10%, P = 0.421) probably because of insufficient prescription of diuretics and low-salt diet. Whereas the prevalence of the triglycerides target was similar, that of total cholesterol (< 200 mg/dl) was larger in diabetology (63%) than in nephrology and primary care (59 and 46%, P = 0.003) because of greater statin prescription in hypercholesterolemic individuals (70, 50 and 41%, respectively, P = 0.002). The attainment of HbA1c less than 7% was less frequent in diabetology (32%) than in nephrology and primary care (61 and 46%, P = 0.0003) despite a more frequent prescription of insulin/oral agents in diabetology. The control of anaemia was better in diabetology. Multivariate analysis adjusted for the patient case-mix and physician-level clustering confirmed these differences except for anaemia.

CONCLUSION

Patients with advanced DN, despite the worst renal and cardiovascular prognosis, are at high risk of being under-treated independently of the type of clinical setting.

Preventive effect of some substances on experimental oxalic calculogenesis in the frog

Rana esculenta tadpoles that are fed spinach develop an oxalic calculogenesis. The addition of cholestyramine, orthophosphate, citrate, allopurinol and tungstate to the tank water prevented calculi formation while succinimide, magnesium oxide, hydrochlorothiazide and tetracycline were ineffective. Methylene blue proved lethal to tadpoles, and its anti-lithogenic activity could not be assessed. These findings, except for the non-effectiveness of magnesium oxide, are in agreement with both the theoretical expectations and the results obtained in other experimental models. Experimental frog calculogenesis seems to be a simple and valid method for evaluating anti-lithogenic activity.

Diphenylamine-induced renal lesions in the chicken

Chronic intoxication with diphenylamine (DPA), which causes a cystic kidney disease in the rat and the guinea-pig, caused degeneration of the renal tubular epithelium in the chicken. This was similar to but much more serious than that preceding the formation of cysts in the rodents, but did not actually result in cyst formation, probably because of the high mortality rate observed in the birds even at this early stage. In the chicken until now it had been possible to obtain a pattern of renal cysts only with polychlorinated biphenyls (PCB) which also induce the "chick oedema" syndrome. The renal lesions due to DPA in the chicken were similar to those produced by PCB, but were not accompanied by oedema, which suggests that "chick oedema" caused by PCB is not due to renal insufficiency. The differences in the renal lesions noted in the various animal species give credit to the hypothesis that DPA may have two effects on the tubular epitelium, one stimulating cell proliferation and one leading to degeneration. Cysts may be formed only in those species in which there is cell proliferation.