Unmet needs for CKD care: from the general population to the CKD clinics-how many patients are we missing?

INTRODUCTION: Prevalence of chronic kidney disease (CKD) varies around the world. Little is known about the discrepancy between the general population's needs and nephrology care offered. We aimed to contribute to filling this gap and propose a means to infer the number of patients needing follow-up. METHODS: All patients undergoing at least one nephrology consultation in 2019 were enrolled. We used the ratio between CKD Stages 3 and 4 reported in the literature, and considered that only 25-50% of CKD Stage 3 patients have progressive CKD, to hypothesize different scenarios to estimate the number of CKD Stage 3 patients still needing nephrology follow-up. RESULTS: The 1992 CKD patients were followed-up in our centre (56.93% males; age 66.71 ± 18.32 years; 16.82% Stage 1; 14.66% Stage 2; 39.46% Stage 3; 19.88% Stage 4; 7.68% Stage 5). The ratio between Stages 3 and 4 in population studies ranged from 7.72 to 51.29, being 1.98 in our centre. Hypothesizing that we followed-up 100, 70 or 50% of CKD Stage 4 patients, 528-2506 CKD Stage 3 patients in our area would need nephrology follow-up [1885-8946 per million population (p.m.p.)]. Three to 17 additional nephrologists p.m.p. would be necessary to fully cover the need for care. CONCLUSIONS: The number of patients with CKD Stage 3 who would benefit from nephrology care is high. Considering that one patient-year of delay of dialysis could cover a nephrologist's annual salary, interventions aimed to improve the care of advanced CKD may be economically sound.

Elderly Patients in a Large Nephrology Unit: Who Are Our Old, Old-Old and Oldest-Old Patients?

The world population is aging, and the prevalence of chronic kidney disease (CKD) is increasing. Whether this increase is also due to the methods currently being used to assess kidney function in the elderly is still a matter of discussion. We aimed to describe the actual referral pattern of CKD patients in a large nephrology unit and test whether the use of different formulae to estimate kidney function could affect the staging and the need for specialist care in the older subset of our population. In 2019, 1992 patients were referred to our center. Almost 28% of the patients were aged ≥80 and about 6% were ≥90 years old. Among the causes of kidney disease, glomerulonephritis displayed a higher prevalence in younger patients whereas hypertensive or diabetic kidney disease were more prevalent in older patients. The prevalence of referred patients in advanced CKD stages increased with age; estimated glomerular filtration rate (eGFR) decreased with age regardless of which equation was used (chronic kidney disease epidemiology collaboration (CKD-EPI), Lund-Malmö Revised (LMR), modification of diet in renal disease (MDRD), Full Age Spectrum (FAS), or Berlin Initiative Study 1 (BIS)). With CKD-EPI as a reference, MDRD and FAS underestimated the CKD stage while LMR overestimated it. The BIS showed the highest heterogeneity. Considering an eGFR threshold limit of 45 mL/min for defining "significant" CKD in patients over 65 years of age, the variability in CKD staging was 10% no matter which equation was used. Our study quantified the weight of "old" and "old-old" patients on follow-up in a large nephrology outpatient unit and suggested that with the current referral pattern, the type of formula used does not affect the need for CKD care within the context of a relatively late referral, particularly in elderly patients.

Identification of the Factors Associated With Intraperitoneal Pressure in ADPKD Patients Treated With Peritoneal Dialysis.

INTRODUCTION: Peritoneal dialysis (PD) is reported to be underused in the autosomal dominant polycystic kidney disease (ADPKD) population because doctors fear technical failure caused by reduced abdominal space and high intraperitoneal pressure (IPP). METHODS: We designed a multicenter retrospective study to be carried out in 15 French centers recruiting 60 patients with ADPKD treated with PD to identify factors associated with IPP. Inclusion criteria were start of PD between 2010 and 2017, available tomodensitometry, and IPP measurement in the first year of dialysis. The clinical and radiological data for each patient were reviewed by the same operator. Total kidney volume (TKV), liver volume, and the volume of the abdominal cavity were measured using contouring. RESULTS: TKV and the volume of the abdominal cavity in women and men were, respectively, 2397 ml versus 3758 ml and 9402 ml versus 12,920 ml. In the univariate analysis, IPP was significantly and positively associated with body surface area (P = 0.0024), body mass index (BMI) (P < 0.0001), the volume of the abdominal cavity (P = 0.0005), and the volume of the dialysate infused in the peritoneal cavity (IPV) (P = 0.0108). In the multivariate analysis, only BMI was still significantly associated with IPP (P = 0.0004). CONCLUSIONS: Our results identified BMI as the main factor linked to IPP in patients with ADPKD. Despite a reliable assessment of the volume of their organs we did not find any correlation between liver and kidney volumes and IPP. To our knowledge, this is the first study designed to identify factors associated with IPP in patients with ADPKD on PD.

Outcome of polycystic kidney disease patients on peritoneal dialysis: Systematic review of literature and meta-analysis.

BACKGROUND: Polycystic kidney disease (PKD) is the most frequent hereditary cause of chronic kidney disease. Peritoneal dialysis (PD) is often avoided for patients with PKD because of the suspected risk of mechanical and infectious complications. Only a few studies have analyzed the outcome of PKD patients on PD with sometimes conflicting results. The purpose of this meta-analysis was to investigate outcomes of patients with PKD treated by PD. METHODS: A systematic review and meta-analysis were performed examining all studies which included "Polycystic kidney disease" and "Peritoneal dialysis" in their titles, excluding commentaries, letters to the authors and abstracts. PubMed, Embase, Google scholar and Scopus were searched to December 31st 2017. The primary outcome was overall patient survival. Additional outcomes were PD technique survival, incidence of peritonitis and incidence of abdominal wall hernia. RESULTS: 9 studies published between 1998 and 2016 were included for analysis with a total of 7,197 patients including 882 PKD patients. Overall survival of PKD patients was found to be better compared to non-PKD patients (HR = 0.70 [95% CI, 0.54-0.92]). There were no statistical differences between PKD and non-PKD patients in terms of peritonitis (OR = 0.86 [95% CI, 0.66-1.12]) and technical survival (HR = 0.98 [95% CI, 0.83-1.16]). There was an increased risk of hernia in PKD patients (OR = 2.28 [95% CI, 1.26-4.12]). CONCLUSIONS: PKD is associated with a better global survival, an increased risk of abdominal hernia, but no differences in peritonitis rate or technical survival were found. PD is a safe dialysis modality for PKD patients. Properly designed controlled studies are needed to determine whether all PKD patients are eligible for PD or whether some specific criteria should be determined.

Outcome of autosomal dominant polycystic kidney disease patients on peritoneal dialysis: a national retrospective study based on two French registries (the French Language Peritoneal Dialysis Registry and the French Renal Epidemiology and Information Network).

Background: Pathological features of autosomal dominant polycystic kidney disease (ADPKD) include enlarged kidney volume, higher frequency of digestive diverticulitis and abdominal wall hernias. Therefore, many nephrologists have concerns about the use of peritoneal dialysis (PD) in ADPKD patients. We aimed to analyse survival and technique failure in ADPKD patients treated with PD. Methods: We conducted two retrospective studies on patients starting dialysis between 2000 and 2010. We used two French registries: the French Renal Epidemiology and Information Network (REIN) and the French language Peritoneal Dialysis Registry (RDPLF). Using the REIN registry, we compared the clinical features and outcomes of ADPKD patients on PD (n = 638) with those of ADPKD patients on haemodialysis (HD) (n = 4653); with the RDPLF registry, those same parameters were determined for ADPKD patients on PD (n = 797) and compared with those of non-ADPKD patients on PD (n = 12 059). Results: A total of 5291 ADPKD patients and 12 059 non-ADPKD patients were included. Analysis of the REIN registry found that ADPKD patients treated with PD represented 10.91% of the ADPKD population. During the study period, PD was used for 11.2% of the non-ADPKD population. Compared with ADPKD patients on HD, ADPKD patients on PD had higher serum albumin levels (38.8 ± 5.3 versus 36.8 ± 5.7 g/dL, P < 0.0001) and were less frequently diabetic (5.31 versus 7.71%, P < 0.03). The use of PD in ADPKD patients was positively associated with the occurrence of a kidney transplantation but not with death [hazard ratio 1.15 (95% confidence interval 0.84-1.58)]. Analysis of the RDPLF registry found that compared with non-ADPKD patients on PD, ADPKD patients on PD were younger and had fewer comorbidities and better survival. ADPKD status was not associated with an increased risk of technique failure or an increased risk of peritonitis. Conclusions: According to our results, PD is proposed to a selected population of ADPKD patients, PD does not have a negative impact on ADPKD patients' overall survival and PD technique failure is not influenced by ADPKD status. Therefore PD is a reasonable option for ADPKD patients.