Children with chronic renal failure in Sweden 1978-1985

A survey of chronic renal failure (CRF) in Swedish children was carried out for the period 1978-1985, using age-related cut-off levels for creatinine concentrations corresponding approximately to a glomerular filtration rate of 30 ml/min per 1.73 m2. The mean annual incidence of CRF was 6.9 and of terminal renal failure (TRF) 4.4/million children. The prevalence increased during the study period, for preterminal renal failure from 14.1 (1978) to 26.1 (1985) and for TRF from 12.4 to 16/million children. The main groups of primary renal disease were malformations (42%), hereditary disorders (27%), and glomerular diseases (14%), while pyelonephritis with vesico-ureteral reflux only made up 5%.     

Children with chronic renal failure in Sweden 1978–1985

A survey of chronic renal failure (CRF) in Swedish children was carried out for the period 1978–1985, using age-related cut-off levels for creatinine concentrations corresponding approximately to a glomerular filtration rate of 30 ml/min per 1.73 m². The mean annual incidence of CRF was 6.9 and of terminal renal failure (TRF) 4.4/million children. The prevalence increased during the study period, for preterminal renal failure from 14.1 (1978) to 26.1 (1985) and for TRF from 12.4 to 16/million children. The main groups of primary renal disease were malformations (42%), hereditary disorders (27%), and glomerular diseases (14%), while pyelonephritis with vesico-ureteral reflux only made up 5%.     

Chronic renal failure in Kuwaiti children: an eight-year experience

Over an 8-year period (January 1996 to December 2003), a total of 171 patients below the age of 15 years were diagnosed with chronic renal failure. The mean incidence rate of CRF in Kuwaiti children was found to be 38.2 per million children per year, with a peak incidence of 55 per million children per year. While the mean age at diagnosis was 33±12 months (range: 1 month to 15 years), the male:female ratio was 2.7:1. Etiological factors for chronic renal failure included congenital urological malformation (61.9%), chronic glomerulopathies (5.2%), hereditary nephropathies (21%), multi-system disease (0.5%), chronic pyelonephritis (without VUR) (4.6%), tumors (0.6%), ischemic renal disease (1.1%) and unknown etiology (1.7%). Thirty percent of patients reached end-stage renal disease within a mean of 18 months following diagnosis. The overall mortality before reaching ESRD was reported to be 4%. Kuwait has one of the highest incidence and prevalence rates of CRF in children. It is likely that genetic and hereditary factors are the cause of these high rates.     

Renal failure in Yemen

Renal failure remains a serious cause of mortality in Yemen. Our region has 1.25 million population and our hospital is the central hospital, which has a nephrology department and performs dialysis for the region. Between January 1998 and December 2002, we admitted 547 patients; including children, with acute renal failure (ARF) and chronic renal failure (CRF). CRF was observed in 400 patients, an incidence of 64 per million per year and a prevalence of 320 per million. ARF occurred in 147 persons with an incidence of 23.5 per million per year and a prevalence of 117.5 patients per million. Of all patients, 72% were adults (age range, 20-60 years) with a male preponderance. As a tropical country, malaria (27.9%), diarrhea (13.6%), and other infectious diseases were the main causes. Next most common were obstructive diseases causing CRF and ARF (26.8% and 12.9%, respectively), mainly urolithiasis, Schistosomiasis, and prostatic enlargement. However the cause of CRF in 57.5% of patients was unknown as most persons presented late with end-stage disease (64.7%), requiring immediate intervention. Other causes, such as hepatorenal syndrome, snake bite, diabetes mellitus, and hypertension, showed low occurrence rates. Patients presented to the hospital mostly in severe uremia and without a clear history of prior medications. The major findings were vomiting, acidosis, and hypertension with serum creatinine values ranging between 2.8-45 mg/dL (mean value, 13.4 mg/dL). Anemia was observed in 80.4% of CRF versus 62.6% of ARF patients. Hypertension prevalence was 65.5% among CRF patients, of whom 25% were in hypertensive crisis, whereas among ARF the prevalence was only 26.5%.     

Epidemiology of chronic renal failure in children: a report from Sweden 1986 – 1994

In a national survey, chronic renal failure (CRF) in Swedish children was studied during the period 1986 – 1994; 118 children (72 boys, 46 girls) with CRF, defined as a glomerular filtration rate below 30 ml/min per 1.73 m² body surface area, were identified. The median annual incidence of CRF was 7.7 and that of terminal renal failure (TRF) 6.4 per million children. The prevalence of preterminal renal failure decreased from 29 to 21 per million children over the study period, while the prevalence of TRF increased from 17.8 in 1986 to 38 per million children in 1994. The increase in TRF prevalence was due to a lower incidence of deaths due to uremia and a slightly increased incidence of TRF compared with an earlier study period, 1978 – 1985. The results point to a more active treatment of uremia in Sweden now than during the period 1978–1985. The congenital causes of CRF (renal malformations, obstructive conditions, and hereditary disorders) accounted for 67.5% of all cases, which is high compared with data from other countries. No child with non-obstructive pyelonephritis as a cause of CRF was identified. Age at detection of CRF and time from detection of CRF to TRF were studied. As a high proportion of children, 42%, reached 16 years of age without entering TRF, the value of presenting time from CRF to TRF for the remaining individuals is questionable. There were only minor differences in primary renal disease, age at presentation, and time from CRF to TRF when the study results were compared with those from 1978 – 1985. Received October 1, 1996; received in revised form and accepted January 21, 1997     

Chronic renal failure in children: a report from Port Harcourt,Nigeria (1985–2000)

A 15-year review of children who presented with chronic renal failure (CRF) to the University of Port Harcourt Teaching Hospital, Rivers State of Nigeria, was carried out. Forty-five children (28 boys, 17 girls) with CRF, defined as a glomerular filtration rate below 30 ml/min per 1.73 m(2) body surface area or a rise in serum creatinine above 120 micro mol/l for at least 6 months, often accompanied by other biochemical abnormalities, were identified. The median annual incidence of CRF was 3.0 per million children. The prevalence of CRF increased from 12.5 in the 1985-1990 periods to 15 per million children after 1995. Acquired disorder was the major cause of CRF. Glomerulopathies were the cause in 53.3% of patients, mainly chronic glomerulonephritis (56.5%) and nephrotic syndrome (30.4%). Hepatitis B surface antigen was positive in 2 patients. Congenital disorders accounted for 28.9% of all cases of CRF, which is lower than data from other countries. Posterior urethral valve was the only congenital disorder causing CRF in the study. No child with hereditary renal disorder as a cause of CRF was identified. Children with congenital disorders were diagnosed at an earlier age. The mortality rate was high (46.7%), as most patients were managed conservatively, since there were no permanent facilities for chronic dialysis or renal transplantation in Nigeria. The study shows that CRF is common in Nigerian children, and there is an urgent need for the establishment of facilities for renal replacement therapy.     

The spectrum of chronic renal failure among Jordanian children

BACKGROUND: The causes of chronic renal failure (CRF) vary from one country to another. In this study we reviewed our experience with the different types of renal disorders leading to CRF in Jordanian children. METHODS: We investigated CRF in 202 Jordanian children (113 males and 89 females) who presented to the Jordan University Hospital, Amman, in the period from July 1988 to April 2001. The mean age at onset of CRF was 7.5 +/- 3.9 years. Patients were followed for 0.6-12.6 years (mean 6.3 years). RESULTS: The causes of CRF included urological abnormalities and malformations (42.1%), hereditary renal disorders (29.7%), glomerulonephritis (GN)(14.4%), renal hypo- or dysplasia (5%), hemolytic uremic syndrome (HUS) (4.5%), and idiopathic (4.5%). Forty-nine patients required renal replacement therapy, most of them with peritoneal dialysis. Nine patients have undergone renal transplantation. We estimated the prevalence of CRF in children in Jordan to be 51 per million population, and the incidence as 10.7 new cases per million-child population per year. CONCLUSION: The high rate of hereditary disorders in our series is attributed to the high prevalence of parental consanguinity in our community. There was a striking number of patients with non-neurogenic neurogenic bladder in our study. The relative incidence of GN leading to CRF in Jordan is lower than in Europe and North America. The relative incidence of the other causes of CRF in our series is similar to many other countries. The incidence and prevalence of CRF in children in Jordan is high compared to other countries.     

Early prognostic factors of infants with chronic renal failure caused by renal dysplasia

Renal dysplasia (RD) is a common cause of chronic renal failure (CRF) in children. The evolution towards end-stage renal failure is unpredictable due to the paucity of early prognostic factors. In order to identify early prognostic clinical criteria, we have retrospectively analyzed renal function and growth in 11 infants with RD and CRF from birth up to 4 years of age. Children with obstructive RD were not included. Glomerular filtration rate (GFR) was estimated from Schwartz formula. In infants with a GFR below 15 ml/min per 1.73 m² at 6 months of age (group A, n=5), kidney function did not further improve; 4 reached end-stage renal failure between 8 months and 6 years of age. In contrast, infants with a GFR above 15 ml/min per 1.73 m² at 6 months of age (group B, n=6) experienced a significant improvement in renal function during follow-up, and none required renal replacement therapy. During the first 3 months of life all infants with RD and CRF developed severe growth retardation. Between 6 months and 4 years of age, children from group B grew significantly better than those from group A. In conclusion, our experience suggests that GFR, estimated from Schwartz formula at 6 months of age, is a useful prognostic factor in infants with RD and CRF. Infants with a GFR below 15 ml/min per 1.73 m² are at risk of severe growth delay and the need for early renal replacement therapy, whereas those with a GFR above 15 ml/min per 1.73 m² have a relatively favorable long-term prognosis. Received: 4 October 1999 / Revised: 26 October 2000 / Accepted: 26 October 2000     

Chronic renal failure in pediatrics 1996

 The Nephrology Branch of the Chilean Pediatric Society has greatly influenced the development of government health plans regarding the management and care of patients under 18 years with chronic renal failure (CRF). In order to assess the status of children with CRF in Chile up to 1996, a questionnaire was sent to all pediatric nephrologists in charge of those children. The total sample was of 227 patients under 18 years, giving a national prevalence of 42.5 and an incidence of 5.7 per million inhabitants; of these patients, 50.7% were male, 58.6% over 10 years and 15% younger than 5 years. The most frequent etiologies of CRF were: obstructive uropathy, 18.1%; hypo/dysplasia, 16.7%; reflux nephropathy, 16.7%; and glomerulopathies, 16.3%. Although 48% of patients were on conservative medical treatment, 42.2% of these were in end-stage renal disease, 22.9% were on dialysis, and 29.1% had undergone renal transplantation. Of the dialysis group, 75% were on peritoneal dialysis. Of the transplanted children, 78.8% had normal renal function, but 16.7% returned to dialysis. Three-year graft survival and patient survival were 68% and 94%, respectively. Received: 19 January 1998 / Revised: 6 July 1998 / Accepted: 16 July 1998     

Long-term outcome of vesicoureteral reflux associated chronic renal failure in children. Data from the ItalKid Project

PURPOSE: The nephropathy associated with vesicoureteral reflux (VUR) is one of the leading causes of chronic renal failure (CRF) in children. We describe the clinical course of the disease based on information available in the ItalKid Project database, and analyze the predictive value of baseline renal function, age at VUR diagnosis and urinary protein excretion in relation to the risk of progressive renal failure. MATERIALS AND METHODS: As of December 31, 2001 the registry included a total of 343 patients (261 males) with a diagnosis of primary VUR, which was the leading single cause of CRF, accounting for 25.4% of all patients with CRF. RESULTS: The estimated risk of end stage renal disease (ESRD) by age 20 years was 56%. The patients with a creatinine clearance (Ccr) of less than 40 ml per minute at baseline had an estimated 4-fold greater risk of ESRD developing in comparison with those whose Ccr was 40 to 75 ml per minute. No significant difference in probability of disease progression to ESRD was found between subjects diagnosed with VUR at age 6 months or less and those diagnosed later (older than 6 months). Furthermore, children with normal urinary protein excretion (a urinary protein [uPr]/urinary creatinine [uCr] ratio of less than 0.2 in 36 patients) and low grade proteinuria (uPr/uCr 0.2 to 0.8 in 34 patients) at baseline showed a significantly slower decrease in mean Ccr than those with moderate proteinuria (uPr/uCr greater than 0.8 in 34 patients). Hypertension and/or antihypertensive treatment (including antiprogressive drugs) were reported in 29.1% of patients. CONCLUSIONS: The results of the present study define the long-term risk of ESRD in a large population of children with CRF and VUR, and provide some critical information for identifying the prognosis.     

Etiology of sustained hypertension in children in the Southwestern United States

We reviewed the records of 132 children with persistent hypertension who were evaluated by our pediatric nephrology services between 1987 and 1991. Eightynine (67%) of these children were found to have renal or renovascular disease, 30 (23%) had primary hypertension and 13 (10%) had a non-renal cause for their hypertension. Glomerulonephritis (n=37) and reflux nephropathy (n=26) were the most frequent renal disorders identified. Renal artery thrombosis was the most common cause of hypertension in the neonatal period (in 6 of 12 neonates, 50%) whereas cystic kidney disease was the most common cause of hypertension in the 1st year of life (in 9 of 30 infants, 30%). The prevalence of primary hypertension increased with age; this diagnosis was made in 16 of 46 (35%) hypertensive patients between 12 and 18 years of age and, more surprisingly, in 8 of 27 (30%) children between 7 and 11 years of age. These data confirm that secondary hypertension is the most common cause of hypertension in children but suggest that primary hypertension is more prevalent than previously recognized in patients between 7 and 18 years of age.     

Impact of ACE I/D gene polymorphism on congenital renal malformations

To investigate the role of the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism on prevalence and progression of disease in children with chronic renal failure (CRF), we determined the ACE I/D genotype in 95 children with CRF due to renal malformations (hypo- /dysplasia, obstructive uropathy, reflux nephropathy; n=59), other congenital or hereditary diseases (n=23), or acquired glomerular disorders (n=13), who had been followed prospectively over a 2-year period. CRF progression rate was followed in each individual by linear regression analysis of estimates of glomerular filtration rate (GFR) obtained every 2 months. Actuarial renal ’survival’ analysis was performed, using a GFR loss of 10 ml/min per 1.73 m² as a cutoff point. The distribution of the ACE genotype did not differ among the disease groups. There was also no difference in ACE genotype distribution between the patients and a control group of healthy Caucasian children (n=163). Among the children with renal malformations, the 2-year renal survival was significantly lower in those with the DD genotype (61%) than in patients with ID or II genotype (89%, P<0.01). In the other disease groups, the ACE I/D genotype was not predictive of CRF progression. In a multivariate analysis of risk factors, the adverse effect of the DD genotype (risk ratio 10.2, P<0.05) was independent of and additive to those of arterial hypertension (RR 13.2, P<0.001) and gross proteinuria (RR 4.7, P<0.05). We conclude that the ACE DD genotype is a significant risk factor for children with congenital renal malformations to develop progressive CRF. The effect of the ACE polymorphism in this patient group is independent of hypertension and proteinuria. Received: 25 August 2000 / Revised: 10 December 2000 / Accepted: 15 December 2000     

Psychiatric disorders in children with chronic renal failure

Psychiatric assessment was done according to the DSM-IV TR criteria in 19 children with predialysis chronic renal failure (CRF) and 19 children with end-stage renal disease on regular hemodialysis. The prevalence rate of psychiatric disorders in all the studied patients was 52.6%. Adjustment disorders were the most common disorders (18.4%), followed by depression (10.3%) and neurocognitive disorders (7.7%). Anxiety and elimination disorders were reported in 5.1 and 2.6%, respectively. The disorders were more prevalent (P=0.05) in dialysis (68.4%) than in predialysis patients (36.8%). The presence of psychiatric disorders was not significantly correlated with sex, severity of anemia, duration of CRF or the efficiency or the duration of hemodialysis. In conclusion, psychiatric disorders were prevalent in our patients, especially in those on hemodialysis. Both adjustments with depression and depressive disorders were the most common psychiatric disorders. This array of disorders was more likely explained by the difficulties encountered in living with CRF rather than by demographic or physical factors.     

Etiology of chronic renal failure in Turkish children

The etiology of chronic renal failure (CRF) was studied in 459 Turkish children (205 girls, 254 boys) for the period January 1979-December 1993. Their mean age at onset of CRF was 9.5±4.2 years (range 1–16 years); CRF was defined as a glomerular filtration rate (GFR) below 50 ml/min per 1.73 m² for at least 6 months. When a GFR determination was not available, the serum creatinine concentration was used: greater than 1 mg/dl for children aged 1–3 years, greater than 1.5 mg/dl for those 3–10 years and greater than 2 mg/dl for those 10–16 years. Primary renal disorders were as follows: reflux nephropathy 32.4% glomerular diseases 22.2%, hereditary renal disorders 11.4%, amyloidosis 10.6%, urinary stones 8% and other renal disorders 15.4%. Twenty-three cases of reflux nephropathy (15.4%) were associated with neural tube defects (NTD) and 20 (13.4%) were caused by infravesical obstruction. CRF caused vesicoureteral reflux associated with NTD and amyloidosis are more frequent in our series compared with west European and Nordic countries.     

The growing volume of diabetes-related dialysis: a population based study.

BACKGROUND: End-stage renal failure requiring dialysis is one of the most serious complications of diabetes mellitus, and diabetes is the most common cause of end-stage renal failure. The aim of this large, observational study is to describe the population-based incidence and prevalence rates and outcomes of diabetic individuals in Ontario, Canada who require dialysis therapy. METHODS: Two cohorts of patients, those with diabetes and those without, were created between April 1, 1994 and March 31, 2000 (total of approximately 8.4 million) and followed until March 31, 2001 using several large, linked administrative databases at the Institute for Clinical Evaluative Sciences. The incidence, prevalence and mortality on dialysis for each cohort were determined. A multivariate Cox proportional hazards analysis, adjusting for age, sex and co-morbidity, was used to determine the independent impact of diabetes on patient survival. RESULTS: The average annual incidence rate of dialysis was 12 times greater in persons with diabetes (130 per 100,000) vs without diabetes (11 per 100,000). By 1999-2000, diabetic patients comprised 51% of the incident dialysis population. The average annual prevalence rate was 10 times greater in the diabetic cohort. Patients with diabetes had more co-morbidities at the start of dialysis and poorer 3 year survival (55 vs 68%; P < 0.0001). CONCLUSIONS: The incident and prevalent rates of dialysis for patients with diabetes mellitus are many times the rates of those without diabetes. Patients with diabetes mellitus often start dialysis with significant co-morbidities, which may contribute to the relatively high rate of mortality on dialysis.     

Spectrum of renal diseases in the elderly: Single center experience from a developing country

From November 1998 to March 2000, two hundredpatients over the age of 60 years (Elderly)with clinical renal disease were studied. 144patients were between ages of 60–69 years, 46between 70–79 years and 10 were above 80 years.The elderly patients (Male 165; Female 35) withrenal disease constituted 11% (200/1816) ofthe total nephrology consultation during thestudy period. The clinical presentationincluded chronic renal failure (42.5%); acuterenal failure (28%); nephrotic syndrome(14.5%); acute glomerulonephritis (7.5%);renal vascular disease (5%) and renal cysticdisease (2.5%). Diabetic nephropathy,obstructive uropathy and hypertensivenephrosclerosis were the major causes of CRF,accounting for 80% of total CRF in theelderly. Chronic glomerulonephritis and chronicpyelonephritis (CPN) were less common andetiology of CRF was uncertain in 5.9% ofcases. However, diabetic nephropathy was thecommonest (49.4%) cause of chronic renalfailure. We did not see a single case ofischemic nephropathy causing CRF in the presentstudy. Prerenal ARF, obstructive uropathy andsepsis were contributing factors for ARF in82% of the cases. Volume depletion due togastrointestinal fluid loss and urinary tractobstruction on account of enlarged prostatewere the leading causes of ARF in 20 (35.7%)and 8 (14.3%) cases respectively. Sepsis withor without multiorgan failure was the major(46.7%:) cause of mortality in patients withARF and overall mortality was 26.8%. Thecommonest (31%) cause of nephrotic syndromewas the idiopathic membranous nephropathy.Diabetic nephropathy related to type-2 diabetesmellitus was the second most common (24.1%)cause of nephrotic syndrome. Diffuseendocapillary proliferative GN of postinfectious etiology was the commonest (73.3%)type of acute GN in our elderly patients. Renalcystic diseases were noted in 5 (ADPKD 3;Simple cyst-2) patients. Thus, overall spectrumof renal disease in our elderly patients issimilar to that of developed nations except intwo ways: (i) Endocapillary proliferative GN ofpost infectious origin was the commonest typeof acute GN and (ii) Rarity or absence ofischemic nephropathy and atherosclerotic renalartery occlusive disease.     

Low prevalence of restless legs syndrome in patients with advanced chronic renal failure in the Indian population: a case controlled study

BACKGROUND: Restless legs syndrome (RLS) is reported to occur in 20-70% of uremic patients. There is no study from India regarding the prevalence of RLS in chronic renal failure (CRF) patients. Studies from other Asian countries have shown a much lower prevalence compared to the West. This study investigated the prevalence of RLS in patients with advanced CRF in the Indian population. Patients and METHODS: Sixty-five CRF patients and 99 controls were evaluated using a predesigned standard questionnaire. The control group consisted of prospective renal donors. RESULTS: The mean age of our patients was 42.4 +/- 14.9 years as compared to 43.7 +/- 11.2 years (p = NS). The distribution of cause of CRF was as follows: diabetes 38.5%, hypertension 13.9%, chronic interstitial nephritis 29.2% and chronic glomerulonephritis 18.4%. RLS was present in 1 patient (1.5%) and none of the controls. CONCLUSION: The prevalence of RLS in CRF patients in India is very low as compared to the Western population.     

慢性肾功能衰竭血液透析患者合并感染的临床分析

目的 探讨慢性肾功能衰竭血液透析患者感染的临床特点和相关因素.方法 回顾分析60例慢性肾功能衰竭透析患者的感染部位、病原菌种类、免疫功能、营养状况、肾功能、原发病因等与感染的相关性.结果 感染组30例患者共发生感染42例次,以肺部感染和静脉导管感染最常见.行各类标本细菌培养40例次,培养阳性24例,病原学检查以革兰阴性...     

The Efficacy of Tc99m Dimercaptosuccinic Acid (Tc-DMSA) Scintigraphy and Ultrasonography in Detecting Renal Scars in Children with Primary Vesicoureteral Reflux (VUR)

Introduction: Pyelonephritis-induced renal scarring in children is a major predisposing factor for proteinuria, hypertension, and ultimate renal failure. The aim of this study was to investigate and compare the efficacy of Tc99m dimercaptosuccinic acid (Tc-DMSA) renal scintigraphy and renal ultrasonography (USG) in detecting renal scars in children with primary vesicoureteral reflux (VUR). Materials and methods: Tc-DMSA scan and USG studies were done in 62 children who were admitted to our clinic between 1997 and 2003 because of documented urinary tract infection (UTI) and diagnosed with primary VUR. Renal scarring detection rates of Tc-DMSA scan and USG were compared according to reflux grades. Results: In the whole group, renal scars were detected by Tc-DMSA scan and USG in 55% and 38% of refluxing units, respectively. Detection rates of Tc-DMSA and USG according to reflux grades were as follows: 47% and 29 % in low-grade VUR (grades 1 and 2), 46 % and 25% in mid-grade VUR (grade 3), 76% and 65% in high-grade VUR (grades 4 and 5), respectively. Conclusion: USG was found to be an inappropriate study in the detection of renal parenchymal scars, irrespective of the reflux grade. In this study, Tc-DMSA scan detected scars in 35% of kidneys reported to be normal on USG.     

Chronic renal failure in children: an epidemiological survey in Lorraine (France) 1975–1990

A comprehensive investigation in Lorraine from 1975 to 1990 identified 127 children (73 boys, 54 girls) under 16 years with chronic renal failure (CRF). From 1975–1980 to 1985–1990 the mean annual incidence of pre-terminal CRF decreased from 12.7 to 7.5 per million children under 16 years of age. The incidence of end-stage renal disease (ESRD) in children increased from 5.6 to 7.5 per million with a peak of 9.1. The prevalence of preterminal CRF was variable (29.4–54) and the prevalence of ESRD increased from 15.5 to 37.0 per million children. Acquired nephropathies were observed in 30.7% and congenital nephropathies in 68.5%. Although patients with acquired nephropathies had only slightly higher serum creatinine levels, they progressed more rapidly to ESRD than those with congenital disease: mean 1.8 years versus 3.85 years after diagnosis of pre-terminal of CRF (P<0.02). Ten years after onset of pre-terminal CRF, 94% with acquired and 69% of those with congenital nephropathies had started renal replacement therapy (P<0.001). It is unclear whether the decrease in preterminal CRF reflects a reduced number of children with kidney disease reaching CRF or is the result of a real delay in the progression due to better therapeutic management.