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.

6-tips diet: a simplified dietary approach in patients with chronic renal disease. A clinical randomized trial

BACKGROUND

The beneficial effects of dietary restriction of proteins in chronic kidney disease are widely recognized; however, poor compliance to prescribed low-protein diets (LPD) may limit their effectiveness. To help patients to adhere to the dietary prescriptions, interventions as education programmes and dietary counselling are critical, but it is also important to develop simple and attractive approaches to the LPD, especially when dietitians are not available. Therefore, we elaborated a simplified and easy to manage dietary approach consisting of 6 tips (6-tip diet, 6-TD) which could replace the standard, non-individualized LPD in Nephrology Units where dietary counselling is not available; hence, our working hypothesis was to evaluate the effects of such diet vs a standard moderately protein-restricted diet on metabolic parameters and patients' adherence.

METHODS

In this randomized trial, 57 CKD patients stage 3b-5 were randomly assigned (1:1) to receive the 6-TD (Group 6-TD) or a LPD containing 0.8 g/kg/day of proteins (Group LPD) for 6 months. The primary endpoint was to evaluate the effects of the two different diets on the main "metabolic" parameters and on patients' adherence (registration number NCT01865526).

RESULTS

Both dietary regimens were associated with a progressive reduction in protein intake and urinary urea excretion compared to baseline, although the decrease was more pronounced in Group 6-TD. Effects on serum levels of urea nitrogen and urinary phosphate excretion were greater in Group 6-TD. Plasma levels of phosphate, bicarbonate and PTH, and urinary NaCl excretion remained stable in both groups throughout the study. 44 % of LPD patients were adherent to the dietary prescription vs 70 % of Group 6-TD.

CONCLUSIONS

A simplified diet, consisting of 6 clear points easily managed by CKD patients, produced beneficial effects either on the metabolic profile of renal disease and on patients' adherence to the dietary plan, when compared to a standard LPD.

[Characteristics of patients with chronic kidney disease referred to a nephrology outpatient clinic: results of Nefrodata study]

Chronic kidney disease is acknowledged as one of the most relevant disease for public health. Knowledge of epidemiology of CKD may allow public health interventions both for prevention and treatment in order to limit burden and management costs. Nefrodata is a multicentric, prospective, and observational study conducted in Italy, including patients with CKD followed in a specialist setting. The study uses a web-based data setting; it includes 1263 subjects with an estimate glomerular filtration rate (eGFR) less than 60 ml/min *1,73 sqm, followed in outpatient clinics in Italy. Patients' characteristics analysis evidences that old subjects (mean age of 70.3 13.4 years, 55% of them older than 70 years), with cardiovascular morbidity (50,6%) and diabetics (37%) have a high prevalence. With the reduction of residual renal function, prevalence of hyperphospatemia, metabolic acidosis, use of erythropoiesis-stimulating agents, Vitamin D, and diuretics increases. Also allopurinol and gastric-protective drugs are widely used. Fifty-four and eight % of patients with CKD stage 4 and 65.9% of patients with CKD stage 5 received indication on nutritional therapy.

Urine creatinine excretion and clinical outcomes in CKD

BACKGROUND AND OBJECTIVES

Twenty-four-hour urine creatinine excretion is a reliable approximation of muscle mass. Whether changes in urine creatinine predict clinical outcomes in persons with CKD is unknown. This work studied the relationship between urine creatinine and patient and renal survival in people with CKD not requiring renal replacement therapy.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This longitudinal cohort study included incident stages 3-5 CKD patients referred to the renal clinic at the University Federico II in Naples between January of 1995 and December of 2005. Clinical data and urine creatinine were updated at each visit. Main outcomes were all-cause mortality and kidney failure requiring dialysis.

RESULTS

This study enrolled 525 individuals and followed them for a median of 6 years (range of 4 months to 15 years). Urine creatinine excretion declined by 16 mg/d per year (95% confidence interval, 14 to 19) in participants with CKD stages 3a, 3b, and 4, and it remained stable in participants with stage 5 CKD. Per each 20 mg/d decline in urine creatinine, mortality increased by 3% (adjusted hazard ratio, 1.03; 95% confidence interval, 1.01 to 1.05), and the risk of initiating dialysis increased by 2% (adjusted hazard ratio, 1.02; 95% confidence interval, 1.01 to 1.03). These associations were independent of body mass index and GFR.

CONCLUSIONS

In persons with CKD stages 3 and 4, urine creatinine declines at a rate of 16 mg/d per year. Lower urine creatinine excretion predicts greater risk of kidney failure and patient mortality.

Nephrotic syndrome and autosomal dominant polycystic kidney disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder characterized by the development and growth of cysts in the kidneys and other organs. In ADPKD patients, nephrotic range proteinuria is unusual and needs to be investigated further to exclude coexisting glomerular disease. Among the anecdotal case reports of ADPKD associated with nephrotic syndrome, focal segmental glomerulosclerosis occurs most frequently.

METHODS

We report the case of a 26-year-old male with ADPKD and concomitant nephrotic syndrome, in which an ultrasound (US)-guided renal biopsy showed a mesangioproliferative glomerulonephritis. We treated the patient with prednisone 1 mg/kg/day, because of the failure of treatment with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker association.

RESULTS

After 6 months of steroid treatment, we observed a stability of his GFR and a reduction of proteinuria.

CONCLUSION

This case report and other cases of the literature underline the importance of a renal biopsy in patients with ADPKD and nephrotic syndrome in order to make an accurate diagnosis and an appropriate treatment/prevention of renal function deterioration.

[Health Technology Assessment to evaluate the economic advantage of offering of low-protein diet to pre-dialysis patients in Campania (Italy)]

A low-protein diet is well known to slow the progression of chronic renal failure, delay initiation of dialysis, while achieving significant economic benefits. In the context of a Health Technology Assessment (HTA), a budget impact analysis model was implemented to evaluate the economic advantage of offering of low-protein diet to nephropathic patients in Campania (Italy). The implemented model takes into account only the direct costs to the national healthcare system. In particular, costs related to supplying low-protein foods are compared to dialysis costs avoided, in a scenario that evaluates different indices of Numbers Needed to Treat and compliance to treatment. Results indicate that when compliance to treatment is at least 50% and NNT is £ 50, supplying a low-protein diet to all kidney disease patients in the pre-dialysis phase, namely with an estimated Glomerular filtration rate &gt; 45, in Campania (which in the year 2009 were equal to 25,000 subjects), is economically advantageous. In this perspective, the authors argue that distribution of low-protein foods by local pharmacies could be an appropriate choice as it would allow the products to be offered at a discounted price and create a favorable setting for increasing adherence to treatment.

Hyporesponsiveness to erythropoiesis-stimulating agents and renal survival in non-dialysis CKD patients

BACKGROUND

Lower responsiveness to erythropoiesis-stimulating agents (ESA-R) predicts cardiovascular (CV) events. Whether ESA-R also affects the risk of end-stage renal disease (ESRD) is unknown.

METHODS

We evaluated ESA-R in 194 consecutive chronic kidney disease (CKD) patients, regularly seen in outpatient nephrology clinics, who started erythropoiesis-stimulating agent (ESA) therapy between 2002-06. Exclusion criteria were causes of anaemia other than CKD or recent transfusion. ESA-R was calculated as (Hb1-Hb0)/time/ESA dose (g/dL/month/10 μg/week of ESA). Patients were classified, from lower to higher tertile of ESA-R, as poor, intermediate and good responders. Time to ESRD was the primary outcome.

RESULTS

Age was 64±16 years, 48% were male, 34% had diabetes and 32% had CV disease, glomerular filtration rate (GFR) 24±13 mL/min/1.73 m2 and proteinuria 0.6 g/dL (interquartile range 0.2-1.9). First ESA dose was 23.7±10.8 μg/week; haemoglobin (Hb) increased from 9.9±0.8 g/dL to 11.0±1.2 g/dL at first control, obtained after 1.4±0.4 months. These changes corresponded to an ESA-R of 0.37±0.38 g/dL/month/10 μg/week of ESA and tertiles limits were 0.17 and 0.47. Poor responders were younger and had lower GFR and higher proteinuria than intermediate and good responders. During the first 6 months of ESA therapy, poor responders showed lower Hb levels and sustained longer periods of Hb level<11 g/dL. During follow-up (median 3.0 years), 99 patients reached ESRD. At multivariable Cox's analysis, poor responsiveness was associated with higher risk of ESRD (hazard ratio 2.49, 95% confidence interval 1.28-4.84).

CONCLUSION

ESA-R predicts renal prognosis in CKD patients followed in nephrology practice, where ESRD is the predominant outcome and ESA is commonly used at low dose.

Prognostic role of ambulatory blood pressure measurement in patients with nondialysis chronic kidney disease

BACKGROUND

Ambulatory blood pressure (BP) measurement allows a better risk stratification in essential hypertension compared with office blood pressure measurement, but its prognostic role in nondialysis chronic kidney disease has been poorly investigated.

METHODS

The prognostic role of daytime and nighttime systolic BP (SBP) and diastolic BP (DBP) in comparison with office measurements was evaluated in 436 consecutive patients with chronic kidney disease. Primary end points were time to renal death (end-stage renal disease or death) and time to fatal and nonfatal cardiovascular events. Quintiles of BP were used to classify patients.

RESULTS

The mean (SD) age of the patients was 65.1 (13.6) years, and the glomerular filtration rate was 42.9 (19.7) mL/min/1.73 m(2); 41.7% of the participants were women, 36.5% had diabetes, and 30.5% had cardiovascular disease. Office-measured SBP/DBP values were 146 (19)/82 (12) mm Hg; daytime SBP/DBP was 131 (17)/75 (11) mm Hg, and nighttime SBP/DBP was 122 (20)/66 (10) mm Hg. During follow-up (median, 4.2 years), 155 and 103 patients reached the renal and cardiovascular end points, respectively. Compared with a daytime SBP of 126 to 135 mm Hg, patients with an SBP of 136 to 146 mm Hg and those with an SBP higher than 146 mm Hg had an increased adjusted risk of the cardiovascular end point (hazard ratio [HR], 2.23; 95% confidence interval [CI], 1.13-4.41 and 3.07; 1.54-6.09) and renal death (1.72; 1.02-2.89 and 1.85; 1.11-3.08). Nighttime SBPs of 125 to 137 mm Hg and higher than 137 mm Hg also increased the risk of the cardiovascular end point (HR, 2.52; 95% CI, 1.11-5.71 and 4.00; 1.77-9.02) and renal end point (1.87; 1.03-3.43 and 2.54; 1.41-4.57) with respect to the reference SBP value of 106-114 mm Hg. Office measurement of BP did not predict the risk of the renal or cardiovascular end point. Patients who were nondippers and those who were reverse dippers had a greater risk of both end points.

CONCLUSION

In chronic kidney disease, ambulatory BP measurement and, in particular, nighttime BP measurement, allows more accurate prediction of renal and cardiovascular risk; office measurement of BP does not predict any outcome.

Prognosis of CKD patients receiving outpatient nephrology care in Italy

BACKGROUND AND OBJECTIVES

Prognosis in nondialysis chronic kidney disease (CKD) patients under regular nephrology care is rarely investigated. Design, setting, participants, & measurements We prospectively followed from 2003 to death or June 2010 a cohort of 1248 patients with CKD stages 3 to 5 and previous nephrology care ≥1 year in 25 Italian outpatient nephrology clinics. Cumulative incidence of ESRD or death before ESRD were estimated using the competing-risk approach.

RESULTS

Estimated rates (per 100 patient-years) of ESRD and death 8.3 (95% confidence interval [CI], 7.4 to 9.2) and 5.9 (95% CI 5.2 to 6.6), respectively. Risk of ESRD and death increased progressively from stages 3 to 5. ESRD was more frequent than death in stage 4 and 5 CKD, whereas the opposite was true in stage 3 CKD. Younger age, lower body mass index, proteinuria, and high phosphate predicted ESRD, whereas older age, diabetes, previous cardiovascular disease, ESRD, proteinuria, high uric acid, and anemia predicted death (P < 0.05 for all). Among modifiable risk factors, proteinuria accounted for the greatest contribution to the model fit for either outcome.

CONCLUSIONS

In patients receiving continuity of care in Italian nephrology clinics, ESRD was a more frequent outcome than death in stage 4 and 5 CKD, but the opposite was true in stage 3. Outcomes were predicted by modifiable risk factors specific to CKD. Proteinuria used in conjunction with estimated GFR refined risk stratification. These findings provide information, specific to CKD patients under regular outpatient nephrology care, for risk stratification that complement recent observations in the general population.

Thyroid function in Fabry disease before and after enzyme replacement therapy

AM: Patients with Fabry disease (FD), a genetic disorder caused by lysosomal a-galactosidase-A enzyme deficiency and characterized by a systemic accumulation of globotriaosylceramides, present high prevalence of subclinical hypothyroidism. The pathogenic mechanism is thought not to be related to anti-thyroid autoimmunity and may be dependent by intra-thyroid lipid accumulation. In this study, it was investigated whether thyroid function recovers in FD after long-term enzyme replacement therapy (ERT).

METHODS

Study population included 14 FD patients (7 females, 7 males, aged 21-62 years) and 14 sex- and age-matched normal subjects. Thyroid function was evaluated in each patient at baseline and after the beginning of ERT with rh-a-galactosidase-A (1 mg/kg/BW every 2 weeks) for three years.

RESULTS

TSH levels were higher in FD patients than in controls (P<0.05). In FD patients, TSH levels were higher before than after ERT (1.9±0.2 vs 1.2±0.2 mU/L, P<0.01) while fT3 and fT4 levels were normal at baseline and unchanged after ERT. At baseline, TSH levels were >3 mU/L in three patients and normalize after ERT. Anti-Tg and/or anti-TPO titres were positive in 14% of patients and 21% of controls. After ERT, the rate of autoimmunity was unchanged. At the thyroid ultrasonography, a slight hypoechoic pattern was found in 71% of patients at baseline and decreased to 43% after ERT.

CONCLUSION

Primary hypothyroidism in FD patients is reverted after long-term ERT. A screening of thyroid function and periodical re-evaluation during ERT is mandatory in all FD patients.

Fabry disease: perspectives of urinary proteomics

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by mutations in the gene encoding the lysosomal enzyme a-galactosidase A (a-GalA). The resulting deficiency in a-GalA activity leads to intra-lysosomal accumulation of neutral glycosphingolipids, mainly globotriaosylceramide (Gb3), in various organ systems. As a consequence, a multisystem disorder develops, culminating in strokes and progressive renal and cardiac dysfunction. Enzyme replacement therapy (ERT) offers a specific treatment for patients affected by FD, though monitoring treatment is hampered by a lack of surrogate markers of response. Furthermore, even if signs and symptoms of the disease become manifest in childhood, its diagnosis is often delayed. Biomarkers that predict disease progression and respond relatively quickly to effective therapy may be useful to follow individual patients or groups of patients. Here we report the use of 2 different mass spectrometry-based proteomic techniques to identify disease-associated compositional changes that can be used as early biomarkers of the pathology, as well as for monitoring the effectiveness of ERT. To this purpose, we compared the renal Fabry urinary proteome with normal (control) urine using, respectively, 2-dimensional gel electrophoresis and label-free quantification. Our preliminary results show that the urinary protein pattern of affected patients can be easily distinguished from that of healthy subjects both qualitatively and quantitatively, thus encouraging further studies in the search for FD-specific biomarkers using this proteomic approach.

Prognostic indicators of renal disease progression in adults with Fabry disease: natural history data from the Fabry Registry

BACKGROUND AND OBJECTIVES

These analyses were designed to characterize renal disease progression in untreated adults with Fabry disease.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from the Fabry Registry for 462 untreated adults (121 men and 341 women) who had at least two estimated GFR (eGFR) values over a span of ≥12 months before starting enzyme replacement therapy were included.

RESULTS

Most men (86 of 121, 71%) had more rapid loss of kidney function than the normal adult population (loss of eGFR > -1 ml/min per 1.73 m(2) per year), whereas fewer women (133 of 341, 39%) had rapid loss of kidney function. Patients with rapid progression had significantly higher mean averaged urinary protein to urinary creatinine ratios (UP/Cr) than patients with slower progression (1.5 versus 0.2 for men; 1.4 versus 0.5 for women; P < 0.0001). Patients were grouped into quartiles based on averaged UP/Cr; renal function in men declined more rapidly with higher UP/Cr, with the steepest declines observed in men with UP/Cr > 1.5 (mean eGFR slope, -5.6 ml/min per 1.73 m(2) per year; n = 30). eGFR slope declined more slowly in women, with the steepest declines observed in women with UP/Cr > 1.2 (mean eGFR slope, -1.3 ml/min per 1.73 m(2) per year; n = 85). Regression models of eGFR slope indicated that UP/Cr is the most important indicator of renal disease progression in adult Fabry patients. In women, lower baseline eGFR and age were also associated with renal disease progression. Women who had clinical events had more rapid loss of kidney function.

CONCLUSIONS

Urinary protein excretion is strongly associated with renal disease progression in men and women with Fabry disease.

Prevalence and prognosis of mild anemia in non-dialysis chronic kidney disease: a prospective cohort study in outpatient renal clinics

BACKGROUND/AIMS

we evaluated prevalence and prognosis of mild anemia, defined as Hb (g/dl) 11-13.5 in males and 11-12 in females, in a prospective cohort of stage 3-5 chronic kidney disease (CKD) patients.

METHODS

we enrolled 668 consecutive patients in 25 renal clinics during 2003. Patients with frank anemia (Hb <11 or erythropoiesis-stimulating agents) at enrolment were excluded. Mild anemia was evaluated at two visits planned with an interval of 18 ± 6 months to identify four categories: no anemia at both visits, mild anemia at visit 1 resolving at visit 2 (RES), mild anemia persisting at both visits (PER), and progression from no anemia or mild anemia at visit 1 to mild or frank anemia at visit 2 (PRO).

RESULTS

mild anemia was present in 41.3% at visit 1 and 34.1% at visit 2. We identified PER in 22% patients, RES in 10%, and PRO in 26%. In the subsequent 40 months, 125 patients developed end-stage renal disease (ESRD) and 94 died. At competing risk model, PER predicted ESRD (hazard ratio, HR, 1.82, 95% confidence interval, CI, 1.01-3.29) while PRO predicted both ESRD (HR 1.81, 95% CI 1.02-3.23) and death (HR 1.87, 95% CI 1.04-3.37).

CONCLUSION

in non-dialysis chronic kidney disease, mild anemia is prevalent and it is a marker of risk excess when persistent or progressive over time.

[Epidemiology of cardiovascular disease in CKD-MBD]

Evidence has been accumulating in recent years that chronic kidney disease (CKD) is a common disease associated with a high risk of morbidity and mortality. Cardiovascular complications are the leading cause of death in patients with CKD, and the risk of cardiovascular mortality is 10-30-fold higher in dialysis patients than in age-, gender- and race-matched controls. On the basis of this evidence it has been suggested that the cardiovascular risk profile of CKD patients is different from that of the general population, resulting from a complex and peculiar interaction of risk factors. In fact, traditional risk factors such as hypertension, aging, smoking, diabetes, and lipid disorders do not fully explain the high frequency of cardiovascular disease in CKD, so other factors must be involved in the high mortality rate in uremic patients. In this article we will provide an overview of the epidemiology of the cardiovascular risk factors in CKD. Among the non-traditional risk factors we have focused particularly on those related to mineral metabolism, which contribute the high rates of cardiovascular events observed in CKD.

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.

[Renal involvement in Fabry's disease: diagnosis, follow-up and enzyme replacement therapy]

Renal involvement in Fabry's disease in males starts at an early age with microalbuminuria and proteinuria and progresses rapidly towards end-stage renal disease requiring dialysis or renal transplantation. Renal involvement, together with cardiac and cerebral damage, is responsible for the severe morbidity and mortality in patients with Fabry's disease. In heterozygous female patients renal involvement has also been documented, but the onset of renal damage occurs later and the progression to end-stage renal disease is slower. Considering the relevance of renal damage in the prognosis of Fabry's disease, it is mandatory to point out the diagnostic criteria of Fabry's nephropathy and the modalities of follow-up of patients with renal involvement. The aim of this study is also to provide recommendations regarding the diagnosis, follow-up and indication for enzyme replacement therapy in patients with Fabry's disease.

Assessment of nutritional practice in Italian chronic kidney disease clinics: a questionnaire-based survey

BACKGROUND

The prevention of malnutrition in patients with progressive chronic kidney disease (CKD) presents a challenge to nephrologists. We evaluated nutritional practice and routines, at a national level, related to the nutritional management of nondialyzed CKD patients.

METHODS

A questionnaire-based survey (32 open and 9 multiple-choice questions) was used to assess the evaluation of nutritional status in nondialyzed CKD outpatients at baseline and during follow-up. Data were obtained for 230 Italian public nephrology centers (63% of the total number of Italian public nephrology centers).

RESULTS

There was a dedicated dietitian at only 19% of the centers. At baseline, body weight, body mass index, and serum albumin were determined in almost all centers, nutrient intakes and bioimpedance analysis in half the centers, and subjective global assessment and skinfold thickness in a small proportion of centers. During follow-up, the rate of assessments decreased by 8% for weight, 14% for nutrient intake, and 29% for subjective global assessment and skinfold thickness. Overall, the K/DOQI minimum criteria for nutritional assessment were fulfilled in only two thirds and half of the clinics at baseline and during follow-up, respectively. Multivariate analysis showed that the number of nutritional variables evaluated was significantly related to the size of the CKD clinic and the presence of a dietitian at baseline, but only with the presence of dietitian during follow-up. Daily urinary output was collected at 90% of the centers, but urea and sodium excretions were determined in only 59% and 57% of cases, respectively. The rate of assessment for urinary solutes during follow-up was higher at centers where a very low protein diet was prescribed.

CONCLUSIONS

The indications about nutritional assessment for CKD patients are poorly translated into practice patterns, especially with respect to the evaluation of nutrient intakes and additional but simple variables such as skinfold-thickness measurement and bioimpedance analysis. The presence of a dedicated dietitian appears to improve the quality of nutritional assessment in CKD.

Effects of enzyme-replacement therapy in patients with Anderson-Fabry disease: a prospective long-term cardiac magnetic resonance imaging study

BACKGROUND

Anderson-Fabry disease is a multisystem X linked disorder of lipid metabolism frequently associated with cardiac symptoms, including left ventricular (LV) hypertrophy gradually impairing cardiac function. Evidence showing that enzyme-replacement therapy (ERT) can be effective in reducing LV hypertrophy and improving myocardial function in the long term is limited.

OBJECTIVE

This study aimed to assess the long-term effects of ERT with recombinant alpha-galactosidase A (agalsidase beta, Fabrazyme) on LV function and myocardial signal intensity in 11 patients with Anderson-Fabry disease.

PATIENTS

Eleven patients (eight males, three females) with varying stages of genetically confirmed Anderson-Fabry disease were examined by means of physical examination and magnetic resonance imaging before ERT with agalsidase beta at 1 mg/kg every other week (study 1) and after a mean treatment duration of 45 months (study 2).

RESULTS

At 45 months of treatment, LV mass and LV wall thickness had significantly reduced: 188 (SD 60) g versus 153 (47) g, and 16 (4) mm versus 14 (4) mm, respectively. Furthermore, a significant reduction in myocardial T2 relaxation times was noted in all myocardial regions, that is, interventricular septum 80 (5) ms versus 66 (8) ms, apex 79 (10) ms versus 64 (10) ms, and lateral wall 80 (8) ms versus 65 (16) ms. Changes in LV ejection fraction were not significant. Amelioration of clinical symptoms was observed in all patients.

CONCLUSIONS

Long-term therapy with agalsidase beta at 1 mg/kg every 2 weeks was effective in significantly reducing LV hypertrophy, improving overall cardiac performance and ameliorating clinical symptoms in patients with Anderson-Fabry disease.

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.

[The usefulness of Cochrane systematic reviews in nephrology]

Systematic reviews (SRs) of the literature are clinical research studies carried out according to rigorous methodological criteria. They are aimed at searching, critically appraising and summarizing all studies with similar characteristics that address the same research question. The Cochrane Collaboration is the main institution that coordinates the production of SRs. The Cochrane Renal Group is one of the 50 research groups of the Cochrane Collaboration and is in charge of SRs in nephrology. This group compiled the Renal Health Library, an annually updated collection of SRs (Cochrane and not) and randomized controlled trials in nephrology, dialysis and renal transplantation. We searched the Renal Health Library to identify SRs useful to answer clinical questions in patients with renal disease and/or following kidney transplant. The SRs identified were summarized and the results were expressed as relative risk, weighted mean difference, standardized mean difference, and 95% confidence intervals. Since the number of randomized controlled trials is quite large and SRs are a reliable summary of the scientific evidence, their distribution is of paramount importance. Here we show several clinical cases where related SRs in the Renal Health Library provide useful guidance for treatment.

Cardiac performance during exercise in patients with Fabry's disease

BACKGROUND

Fatigability and dyspnoea on effort are present in many patients with Fabry's disease. We assessed the determinants of cardiac performance during exercise in patients with Fabry's disease and preserved left ventricular ejection fraction at rest.

MATERIALS AND METHODS

Sixteen patients with Fabry's disease and 16 control subjects underwent radionuclide angiography at rest and during exercise, tissue Doppler echocardiography and magnetic resonance imaging at rest.

RESULTS

The exercise-induced change in stroke volume was +25 +/- 14% in controls and +5.8 +/- 19% in patients with Fabry's disease (P < 0.001). In 10 patients (group 1), the stroke volume increased (+19 +/- 10%), and in 6 patients (group 2) it decreased (-16 +/- 9%) with exercise. Patients of group 2 were older, had worse renal function, higher left ventricular mass and impaired diastolic function compared to group 1. The abnormal stroke volume response to exercise in group 2 was associated with a decrease in end-diastolic volume (P < 0.001) and a lack of reduction of end-systolic volume (P < 0.01) compared with both controls and group 1. The ratio of peak early-diastolic velocity from mitral filling to peak early-diastolic mitral annulus velocity was the only independent predictor of exercise-induced change in stroke volume (B -0.44; SE 0.119; beta-0.70; P < 0.005).

CONCLUSIONS

The majority of patients with Fabry's disease were able to augment stroke volume during exercise by increasing end-diastolic volume, whereas patients with more advanced cardiac involvement may experience the inability to increase cardiac output by the Frank Starling mechanism.

Italian randomized trial of hemoglobin maintenance to prevent or delay left ventricular hypertrophy in chronic kidney disease

BACKGROUND

This study is part of a 3-country study testing whether normal levels of hemoglobin (Hgb) delay the progression of left ventricular (LV) growth in chronic kidney disease (CKD) patients not on dialysis.

METHODS

This was an open-label, randomized, multicenter, controlled trial conducted in 27 tertiary-care hospitals in Italy. Treated subjects (n=46) received epoetin-alpha (EPO-alpha) to maintain Hgb levels in the range 12-14 g/dL. Control subjects (n=49) were not treated unless their Hgb decreased to 9.0 g/dL. Primary outcome was LV mass index (MI) change after 24 months. Subcutaneous EPO-alpha was withdrawn in Europe and the study prematurely terminated; therefore, a 12-month analysis was carried out.

RESULTS

Mean age was 57 years (38% were women, 18% with diabetes, 76% taking ACEI or ARB and 22% statins). EPO-alpha median final dose was 2,000 IU/week. Hgb significantly increased (12.4 -/+ 1.1 g/L) for the treatment group and decreased for controls (11.3 -/+ 1.3 g/L; p<0.001). The intention-to-treat analysis was conducted in 78 patients. Mean baseline LVMI for treated patients and controls was 109.5 -/+ 23 g/m2 and 108.7 -/+ 29 g/m2, respectively. LVMI did not change among controls, whereas it decreased slightly, though not significantly, among treated patients.

CONCLUSIONS

The current Italian trial was negative, maybe due to its limitations: lack of power, 1-year follow-up and normal LVMI in some patients at start; however, it was consistent with other published studies. Thus, it is unlikely that targeting hemoglobin in the normal range for CKD patients is of benefit.

[Altered calcium-phosphorus metabolism and low-protein diet]

Many metabolic disorders associated with uremia can affect the long-term survival of patients with chronic kidney disease. Such disorders can be defined as: hypocalcemia, increased levels of phosphorus, reduced synthesis of 1,25-dihydroxyvitamin D and serum calcitriol, and reduced expression of vitamin D receptors on parathyroid cells with increased parathyroid hormone levels and secondary hyperparathyroidism. Phosphorus, which plays a crucial role in the progression of progressive renal disease, has been shown to be an independent risk factor for death in hemodialysis patients. Thus, reducing the phosphorus intake by decreasing dietary proteins may slow the progression of renal disease. Hypocalcemia is typically associated with chronic kidney disease. It is due to the reduced intestinal absorption of calcium and the spontaneously reduced protein intake that occur in patients with progressive renal disorders. Activated vitamin D and calcium supplements should be administered to patients who are following low-protein diets to prevent secondary hyperparathyroidism; the doses should be correlated with actual renal function and protein intake.

[Relationship between low-protein diet and hypertension control]

Arterial hypertension is found in almost all patients with chronic kidney disease. The US Kidney Foundation guidelines recommend a pressure target for chronic kidney disease patients (130/80 mmHg) that may be difficult to reach because of the reduced sodium excretion in these patients and the widespread use of vasodilator drugs. Reducing the dietary protein intake may help to lower the dietary sodium load. The 130/80 mmHg target has been reached in 30% of stage 4 and 5 patients only after six months of a very low-protein diet supplemented with keto-analogues and essential amino acids. However, even moderate reductions of dietary sodium intake are useful in patients with compromised renal function, as was shown by Koomans et al more than 20 years ago. Blood pressure levels are lower in vegetarians, possibly also because of the reduced sodium content of potassium-rich vegetarian diets. Diets rich in unrefined cereals, vegetables, fruit and low-fat cheese may be useful in patients with chronic kidney disease. Commercial low-protein preparations may help to design diets that are both low in sodium, potassium and phosphorus and adequate for caloric needs.

[Low-protein diet in Italy today: the conclusions of the Working Group from the Italian Society of Nephrology]

The high estimated prevalence of chronic kidney disease (CKD) forcefully supports the need for collaboration among nephrologists, cardiologists, diabetologists and general practitioners, to reduce the cardiovascular risk of CKD patients and delay the start of dialysis. Many studies confirm that reducing the dietary intake of proteins improves uremia as well as acid-base and phosphorus disorders without exposing the CKD patient to the risk of malnutrition. The possibility of delaying renal death and the start of dialysis by almost one to two years is also recognized, thanks in part to the antiproteinuric effect of low-protein diets supplemented with keto acids and essential amino acids. Reducing the dietary protein intake delays the start of dialysis independently of the effect of renin-angiotensin system (RAS)-active antihypertensive drugs. Reduction of the dietary protein intake is indicated in patients with a glomerular filtration rate <25 mL/min (CKD stages 4 and 5). Some situations may, however, require an earlier switch to a low-protein diet, e.g., high proteinuria, renal function worsening at more than 5 mL/min/year, diabetes, and metabolic decompensation. If well designed and properly carried out, reduction of the dietary intake of proteins is not associated with low serum albumin levels or malnutrition, and does not affect patients death. Today, highly palatable, high-quality reduced protein preparations are widely available to reduce the protein intake of CKD patients.

[Low-protein dietary therapy in patients with chronic kidney disease]

Several prospective studies and meta-analyses including the recent Cochrane meta-analysis have demonstrated that reducing the protein content in the diet delays renal death and the start of dialysis in patients with chronic kidney disease (CKD). Reducing the dietary protein intake offers other benefits such as lowering accumulation of uremic toxins and circulating phosphates and improving symptoms and metabolic derangements. Following the publication of the Cochrane meta-analysis, some of the most renowned experts in Italy on dietary therapy in the CKD patient established a working group within the Italian Society of Nephrology (SIN), the ''Nephrontieres'' project. The current supplement of GIN presents the views of the members of the ''Nephrontieres'' group on a range of issues related to dietary therapy in CKD. A CME program for Italian nephrologists also originated from the collaborative work of the group.

Detection and awareness of moderate to advanced CKD by primary care practitioners: a cross-sectional study from Italy

BACKGROUND

Chronic kidney disease (CKD) is a strong independent predictor of cardiovascular disease. Although general practitioners (GPs) represent the first line for identification of these high-risk patients, their diagnostic approach to CKD is ill defined.

STUDY DESIGN

Cross-sectional evaluation of database of Italian GPs.

SETTING & PARTICIPANTS

Representative sample of adult Italian population regularly followed up by GPs in 2003.

OUTCOMES

Frequency of serum creatinine testing, prevalence of CKD (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m(2)), awareness of CKD assessed from use of diagnostic codes (Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM]) for CKD, and referral to nephrologists.

RESULTS

Of 451,548 individuals in the entire practice population, only 77,630 (17.2%) underwent serum creatinine testing. Female sex (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.06 to 1.12), advanced age (OR, 2.70; 95% CI, 2.63 to 2.78), diabetes (OR, 1.31; 95% CI, 1.20 to 1.42), hypertension (OR, 1.10; 95% CI, 1.02 to 1.19), autoimmune diseases (OR, 1.42; 95% CI, 1.11 to 1.82), and recurrent urinary tract infections (OR, 1.63; 95% CI, 1.10 to 2.42) were all associated with serum creatinine testing. Conversely, use of either nonsteroidal anti-inflammatory drugs (OR, 1.03; 95% CI, 0.89 to 1.21) or aminoglycosides or contrast media (OR, 0.78; 95% CI, 0.54 to 1.14) was not associated with serum creatinine testing. In the subgroup with serum creatinine data, the age-adjusted prevalence of CKD was 9.33% (11.93% in women, 6.49% in men). However, in patients with eGFR less than 60 mL/min/1.73 m(2), serum creatinine values were apparently normal (<1.2 mg/dL in women, <1.4 mg/dL in men) in 54%, and GPs used ICD-9-CM codes for CKD in only 15.2%. Referral to nephrologists ranged from 4.9% for patients with eGFR of 59 to 30 mL/min/1.73 m(2) to 55.7% for those with eGFR less than 30 mL/min/1.73 m(2).

LIMITATIONS

The prevalence of decreased kidney function may be overestimated because of the more frequent serum creatinine testing in sicker individuals and lack of creatinine calibration.

CONCLUSIONS

In primary care, CKD stages 3 to 5 are frequent, but its awareness is scarce because of limited rates of serum creatinine testing and difficulty recognizing decreased eGFR in the absence of increased serum creatinine testing.

Renal transplantation and sleep: a new life is not enough

Renal transplantation is associated with better survival and improved quality of life compared to maintenance dialysis. Although many sleep disorders improve or even disappear after a successful transplantation, sleep quality remains low, and the prevalence of sleep complaints, although lower than in dialysis patients, is much higher than in the general population. Few studies have dealt with sleep problems of renal transplant patients: despite reporting obvious differences in the prevalence of the single sleep disorders, all underline the importance of psychological problems in conditioning sleep. In the diagnosis of sleep disorders, the nephrologist must learn to distinguish medical risk factors (pain, pruritus, tremors, drugs) and psychological aspects (depression, anxiety, fear), since they are potentially modifiable with the appropriate treatment.

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.

Nephropathy in males and females with Fabry disease: cross-sectional description of patients before treatment with enzyme replacement therapy

BACKGROUND

Fabry disease, an X-linked genetic disorder with deficient alpha-galactosidase A activity, is characterized by kidney disease and kidney failure. The spectrum of kidney disease has not been well defined, especially in female patients.

METHODS

We did a cross-sectional retrospective analysis of natural history of glomerular filtration rate (estimated- eGFR), albuminuria and proteinuria in 1262 adult patients (585 males, 677 females) from the Fabry Registry.

RESULTS

Twenty-eight percent of males (age 20-79 years) and 13% of females (age 20-82 years) had chronic kidney disease (CKD) with eGFR < 60 ml/min/1.73 m(2). Overt proteinuria (>300 mg/24 h) was demonstrated in 43 and 26% of males and females with CKD stage 1, respectively, and the proportions were higher with more severe kidney involvement. However, 11% of males and 28% of females with eGFR < 60 ml/min/1.73 m(2) had proteinuria <300 mg/ 24 h. Of eGFR >/= 60 ml/min/1.73 m(2) patients without overt proteinuria (n = 93), 55% of the males and 35% of the females had albuminuria >30 mg/24 h. Systemic blood pressure was >/=130/80 mmHg in 48% and 67% of patients with eGFR >/= and <60 ml/min/1.73 m(2), respectively, with no significant differences between males and females. Proteinuria values were significantly correlated with systolic blood pressure in both sexes.

CONCLUSIONS

Kidney involvement in Fabry disease is more prevalent and heterogeneous than previously reported. Proteinuria is an early complication, but may not be overt in patients with advanced kidney disease. This analysis, which includes more females than males, confirms that a significant proportion of females suffer moderate to severe kidney involvement in Fabry 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.

Prevalence and clinical correlates of white coat hypertension in chronic kidney disease

BACKGROUND

The role of white coat hypertension (WCH) in the poor control of blood pressure (BP) in chronic kidney disease (CKD) is ill defined.

METHODS

We measured systolic clinical (CBP) and ambulatory blood pressure (ABP) in 290 consecutive patients with non-dialysis CKD [glomerular filtration rate (GFR) <60 ml/min/1.73 m(2)]. We defined normotension (NOR) if CBP and daytime ABP <130 mmHg, sustained hypertension (SH) when both BP >or=130 mmHg, WCH if only daytime ABP <130 mmHg, and masked hypertension (MH) when only CBP <130 mmHg.

RESULTS

NOR patients were 15.5%, WCH 31.7%, SH 46.9% and MH 5.9%. Due to the high prevalence of WCH, achievement of BP target (<130 mmHg) was more than doubled by daytime ABP than CBP (47.2 vs 21.4%). WCH was characterized by prevalence of diabetes (31.5%), left ventricular hypertrophy (LVH; 50.0%) and CBP values (146 +/- 12 mmHg) lower than in SH (41.9%, 71.3% and 158 +/- 18 mmHg) but greater than in NOR (17.8%, 37.8% and 118 +/- 7 mmHg). Among patients with CBP >or=130 mmHg, the independent risk of having SH rather than WCH increased in the presence of higher CBP [Odds ration (OR) 1.61, 95% confidence intervals (CI) 1.29-2.02], LVH (OR 1.94, 95% CI 1.03-3.63) and proteinuria (OR 3.12, 95% CI 1.31-7.43). In the WCH group, 24 h, daytime and nighttime ABP were 118 +/- 7/68 +/- 8, 120 +/- 7/71 +/- 8 and 112 +/- 12/63 +/- 9 mmHg, respectively.

CONCLUSIONS

In CKD, WCH is highly prevalent and can be predicted in the absence of higher CBP, LVH and proteinuria. In these patients, pursuing a low BP target may not be safe because of the risk of cardio-renal hypoperfusion especially at nighttime.

MRI Characterization of Myocardial Tissue in Patients with Fabry's Disease

OBJECTIVE

Fabry's disease is a multisystem X-linked disorder of lysosomal metabolism frequently associated with left ventricular (LV) hypertrophy. In this study, we aimed to assess whether myocardial T2 relaxation time determined by a black blood multiecho multishot MRI sequence could be used to evaluate cardiac involvement in patients with Fabry's disease.

CONCLUSION

Myocardial T2 relaxation time is prolonged in patients with Fabry's disease compared with that of hypertrophic patients and healthy control subjects. MRI may be useful for the characterization of myocardial tissue in patients with Fabry's disease.

[Use of statins for preventing cardiovascular and renal outcomes in patients with chronic kidney disease excluding dialysis: guideline from the Italian Society of Nephrology]

BACKGROUND

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. In the present guideline, evidence of the efficacy of statins in chronic kidney disease patients (CKD, non-dialysis patients) is presented.

METHODS

SR of RCT and RCT on statins in CKD (non-dialysis) patients were identified referring to a Cochrane Library and Renal Health Library search (2005 update). Quality of SR and RCT was assessed according to current methodological standards.

RESULTS

Three SR and 36 RCT were found addressing this intervention issue. Methodological quality of the relevant RCT was suboptimal. There is no enough evidence to suggest that statins are associated with a significant reduction in the risk of serum creatinine doubling or of end-stage renal disease in CKD patients (evidence from SR and RCT). Statins compared to placebo or no treatment are associated with significant improvements in proteinuria (evidence from SR). Statins are also associated with significant reduction in the risk of cardiovascular events and mortality in CKD patients (evidence from SR and RCT) and in renal transplant recipients (evidence from RCT), and no significant increases in the risk of rhabdomyolysis and hepatotoxicity in CKD patients.

CONCLUSION

Available evidence supports the hypothesis that statins should be recommended in CKD patients (non-dialysis patients) on the basis of significant evidence of cardiac and renal protection and no evidence of significant harms. Further studies are necessary to test this hypothesis in selected patient populations.

[Antihypertensive agents for the prevention of chronic kidney disease progression: guideline from the Italian Society of Nephrology]

BACKGROUND

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. In the present guideline, evidence of the use of antihypertensive agents to prevent chronic kidney disease progression (CKD) is presented.

METHODS

SR of RCT and RCT on antihypertensive agents used to prevent CKD progression were identified referring to a Cochrane Library and Renal Health Library search (2005 update).

RESULTS

Seven SR and 26 further RCT were found addressing this intervention issue. Methodological quality of available RCT was suboptimal according to current methodological standards. Angiotensin converting enzyme inhibitors (ACE-I) are associated with significant effects on the prevention of CKD progression in non-diabetic and diabetic patients (evidence from SR). Angiotensin receptor blockers (ARB) are as effective as ACE-I in delaying CKD progression in diabetic and non-diabetic patients (evidence from SR). Dihydropyridine and non-dihydropyridine calcium antagonists have not been found to significantly affect proteinuria and CKD progression (evidence from SR). Combination therapy with ACE-I and ARB is associated with a significant reduction in the risk of CKD progression and proteinuria, but long term data are only available in patients with non-diabetic nephropathy (evidence from RCT).

CONCLUSION

Available evidence of renal protection suggest that ACE-I and ARB should be recommended in CKD patients (diabetic and non-diabetic nephropathy). Further studies are necessary to test the effectiveness of other antihypertensive agents or combination therapy.

[Erythropoietins and haemoglobin targets to prevent the progression of chronic kidney disease: guideline from the Italian Society of Nephrology]

BACKGROUND

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of Systematic Reviews (SR) of Randomized Trials (RCT) or RCT data only. The present guideline reports evidence of the use of Erythropoietins (EPO) and/or optimal haemoglobin (Hgb) targets to delay Chronic Kidney Disease (CKD) progression.

METHODS

SR of RCT and RCT on EPO and different Hgb targets in CKD (pre-dialysis) were identified searching in the Cochrane Library and Renal Health Library (2005 update). Quality of SR and RCT was assessed according to current methodological standards.

RESULTS

Two SR (15 RCT) and 5 further RCT were found addressing the intervention issue. No significant evidence supporting the use of EPO compared with placebo/no treatment to prevent or delay CKD progression was found (evidence from SR). Progression rates do not appear to be affected by Hgb targets (evidence from SR). Methodological quality of included RCT was suboptimal. In diabetic patients not receiving renin-angiotensin-system inhibitors, early EPO treatment (when Hgb ≥9 g/dL) with target Hgb ≥13 g/dL as compared to delayed treatment initiation (Hgb < 9 g/dL) is associated with reduced risk of disease progression, end-stage renal disease and death (evidence from RCT).

CONCLUSION

In CKD patients not undergoing dialysis current evidence does not support the hypothesis that EPO treatment or optimal Hgb targets reduce the progression rate of the disease. Further studies are necessary to test this hypothesis in selected patient populations.

Endocrine dysfunction in patients with Fabry disease

BACKGROUND

Fabry disease (FD) is a genetic disorder caused by lysosomal alpha-galactosidase-A deficiency and is characterized by the systemic accumulation of globotriaosylceramide. All endocrine glands are susceptible to globotriaosylceramide accumulation because of their high vascularization and low cellular proliferation rate. Nevertheless, this endocrine system has never been investigated in detail.

OBJECTIVE

We aimed to investigate the function and morphology of the endocrine glands in FD.

PATIENTS

The thyroid, gonadal, adrenal, and GH/IGF-I axes were evaluated in 18 FD patients (nine females and nine males, aged 21-64 yr) and 18 sex- and age-matched healthy subjects.

STUDY DESIGN

We conducted an observational, analytical, open, prospective study.

INTERVENTIONS

Ten of the 18 patients received enzyme replacement therapy (ERT) with recombinant human alpha-galactosidase-A (agalsidase beta) at a dose of 1 mg/kg body weight every 2 wk.

RESULTS

FD patients had higher baseline TSH levels than controls (P < 0.01). Three subjects were diagnosed with an early stage of subclinical primary hypothyroidism associated with negative antithyroid antibodies. A history of menses abnormalities, miscarriage, or assisted delivery was found in 89% of FD women. Asthenozoospermia, oligozoospermia, or both were found in all FD men through seminal fluid analysis. FD patients had significantly higher circulating ACTH and lower cortisol levels than controls (P < 0.05). In patients under ERT, a suboptimal cortisol response to the 250-microg ACTH test was found in 10%, and the ACTH-stimulated cortisol peak was significantly correlated to the health status profile (P < 0.05).

CONCLUSION

A variety of latent endocrine dysfunctions, including life-threatening conditions, occur in patients with FD. Endocrine dysfunctions are also present in patients already receiving ERT and are in part related to their persistent poor quality of life. An endocrine work-up should be recommended in all FD patients. Adequate monitoring and hormonal therapy, when required, have to be performed in cases of subclinical endocrine dysfunction to avoid life-threatening events.

Inhibition of Ras/ERK1/2 signaling protects against postischemic renal injury

The small GTPase p21 Ras and its downstream effectors play a central role in the control of cell survival and apoptosis. We studied the effects of Ras/ERK1/2 signaling inhibition on oxidative damage in cultured renal and endothelial cells and on renal ischemia-reperfusion injury in the rat. Primary human renal tubular and human endothelial ECV304 cells underwent significant cell death when subjected to oxidative stress. This type of stress induced robustly ERK1/2 and phosphoinositide 3-kinase (PI3-kinase) signaling. Inhibition of Ras/ERK1/2 with a farnesyl transferase inhibitor, chaetomellic acid A (S-FTI), or with PD-98059, an inhibitor of MEK, a kinase upstream ERK1/2, significantly reduced the fraction of dead cells. The inhibitor of the PI3-kinase/Akt pathway, LY-294002, failed to exert a protective effect. We have translated these data in a rat model of renal ischemic injury in vivo. In uninephrectomized animals, anesthetized with pentobarbital sodium (Nembutal, 50 mg/kg i.p.), 24 h after an acute ischemic renal insult (45-min occlusion of left renal artery) a significant fraction of kidney cells succumbed to cell death resulting in renal failure [glomerular filtration rate (GFR) 0.17 +/- 0.1 vs. 0.90 +/- 0.4 ml x min(-1) x 100 g body wt(-1) in normal rats]. Rats treated with S-FTI maintained the renal function (GFR 0.50 +/- 0.1 ml x min(-1) x 100 g body wt(-1)), and the kidneys showed a significant reduction of tubular necrosis. Reduction of ischemic damage in kidney and tubular cells paralleled Ha-Ras inhibition, assayed by cytosolic translocation of the protein. These data demonstrate that inhibition of farnesylation and consequently of Ras/ERK1/2 signaling significantly reduces acute postischemic renal injury.