Papers by Piergiorgio Bolasco
Panminerva Medica, Feb 1, 2017
The manipulation of dietary protein intake is the mainstay of nutritional treatment of patients a... more The manipulation of dietary protein intake is the mainstay of nutritional treatment of patients affected by chronic renal insufficiency, with the aim to reduce the burden of uremic toxins in order to decrease uremic toxicity and delay the need for dialysis. Consensus exists regarding the benefit of progressive protein restriction towards delaying the progression of renal failure and the need for dialysis, provided adequate energy supply. Although pivotal, protein restriction is only one aspect of the dietary management of chronic kidney disease (CKD) patients. Additional features, though strictly related to proteins, include modifications in sodium, phosphorus and energy intake, as well as in the source (animal or plant derived) of protein and lipids. In addition, supplements play an important role as a means to obtain both beneficial effects and nutritional safety in the renal patient. Essential amino acid and ketoacid mixtures are the most utilized types of supplementation in CKD patients on restricted protein regimens. The essential amino acids plus ketoacid supplementation is mandatory in conjunction with a very low-protein diet in order to assure an adequate essential amino acid supply. It is needed to safely implement a very low protein (and phosphorus) intake, so as to obtain the beneficial effect of a severe protein restriction while preventing malnutrition. Protein-free products and energy supplements are also crucial for the prevention of protein-energy wasting in CKD patients. Calcium, iron, native vitamin D and omega-3 PUFAs are other types of supplementation of potential benefits in the CKD patients on conservative management.
Blood Purification, 2012
This report attempts to illustrate the positive impact on the quality of dialysis water produced ... more This report attempts to illustrate the positive impact on the quality of dialysis water produced over a 16-year period through the progressive optimization of technological procedures. Methods: Fundamental steps included the following: elimination of polyvinyl chloride (PVC), periodical controls, introduction of stainless steel and/or polyethylene polymer and substitution of single-pass reverse osmosis (SRO) with double-pass reverse osmosis (DRO). Daily overnight automatic thermal disinfection of distribution piping rings represented the final step. Results: A dramatic improvement was observed in 645 water samples obtained from distribution piping. The measures applied resulted in a significant improvement of water quality, featuring levels of colony-forming units per milliliter ranging from 247.4 8 393.7 in the presence of PVC and SRO to 14.1 8 28.0 with stainless steel and DRO and 2.8 8 3.2 with cross-linked polyethylene thermoplastic polymer and DRO (p ! 0.01). Conclusions: Dialysis water should be viewed by nephrologists as a medicinal product, and every effort should be made to ensure a high-quality liquid.
Journal of The American Society of Nephrology, Oct 1, 2010
Symptomatic intradialytic hypotension is a common complication of hemodialysis (HD). The applicat... more Symptomatic intradialytic hypotension is a common complication of hemodialysis (HD). The application of convective therapies to the outpatient setting may improve outcomes, including intradialytic hypotension. In this multicenter, open-label, randomized controlled study, we randomly assigned 146 long-term dialysis patients to HD (n ϭ 70), online predilution hemofiltration (HF; n ϭ 36), or online predilution hemodiafiltration (HDF; n ϭ 40). The primary end point was the frequency of intradialytic symptomatic hypotension (ISH). Compared with the run-in period, the frequency of sessions with ISH during the evaluation period increased for HD (7.1 to 7.9%) and decreased for both HF (9.8 to 8.0%) and HDF (10.6 to 5.2%) (P Ͻ 0.001). Mean predialysis systolic BP increased by 4.2 mmHg among those who were assigned to HDF compared with decreases of 0.6 and 1.8 mmHg among those who were assigned to HD and HF, respectively (P ϭ 0.038). Multivariate logistic regression demonstrated significant risk reductions in ISH for both HF (odds ratio 0.69; 95% confidence interval 0.51 to 0.92) and HDF (odds ratio 0.46, 95% confidence interval 0.33 to 0.63). There was a trend toward higher dropout for those who were assigned to HF (P ϭ 0.107). In conclusion, compared with conventional HD, convective therapies (HDF and HF) reduce ISH in long-term dialysis patients.
Metabolites, Oct 18, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Giornale di clinica nefrologica e dialisi, May 24, 2018
Practical paths to undertake a one-week dialysis program combined with a nutrition personalized h... more Practical paths to undertake a one-week dialysis program combined with a nutrition personalized hypoproteics The aim of this article is to provide detailed information to nephrologists on how to apply the combined diet dialysis program (CDDP) in selected patients. Patients are evaluated by urea nitrogen appearance, which allows the sustainability and compliance of patients on 0.6 g/kg per day low-protein diet to be verified by calculating the protein catabolic rate at a metabolic steady state. The combined action of nutrition and less frequent hemodialysis may preserve residual renal function with a further chance of achieving greater excretion of the protein-bound uremic toxins, thereby obtaining a positive phosphate balance. This paper describes all fundamental steps and calculations, although a greater clinical commitment is required to achieve a tailored therapeutic protocol such as Combined Diet Dialysis Program (CDDP).
Journal of Renal Nutrition, Mar 1, 2019
Objective: The objective of the study was to quantify the loss of total amino acids (TAAs), nones... more Objective: The objective of the study was to quantify the loss of total amino acids (TAAs), nonessential amino acids, essential amino acids, and branched chain amino acids (BCAAs) produced by high-efficiency hemodialysis (HEHD), postdilution hemodiafiltration (HDFpost), and predilution hemodiafiltration (HDFpre) using high ultrafiltration volumes; and to define the specific AA losses registered in HEHD, HDFpost, and HDFpre; to identify a potential metabolic and nutritional decline into protein energy wasting; to compare AA analysis of arterial blood samples taken from healthy controls and patients with end-stage renal disease undergoing hemodialysis. Design and Methods: Identical dialysis monitors, membranes, and dialysate/infusate were used to homogenize extracorporeal body influence. Ten patients were recruited and randomized to receive treatment with HEHD, HDFpost, and HDFpre it was used on-line dialytic water methodologies (OL); patients' AA arterial concentrations were measured at the start and on completion of dialysis; TAA from the dialyzer filter was calculated, and baseline levels were subsequently compared with findings obtained 1 year later. Finally, the results obtained were compared with the data from a study of 8 healthy volunteers conducted using bioimpedance analysis and laboratory blood tests to assess nutritional status. Results: A higher convective dose results in a higher weekly loss of TAA, nonessential AAs, essential AAs, and BCAAs (HEHD: 15.7 g; HDFpost-OL: 16.1 g; HDFpre-OL: 16.3 g, P , .01). After 12 months, the same hemodialys patients showed a reduced body and water intracellular mass and reduced phase angle. Arterial concentrations of TAAs and BCAAs were lower than those detected in healthy subjects (P , .01). Conclusion: The study shows that the AA losses in dialytic liquid are greater after high exchange volume HDF techniques, especially HDFpre. The AA losses are not metabolically compensated, so these increase the derangements of predialytic arterial plasma AA levels. Both AA losses and arterial AA perturbations further worsened body composition already after 12 months of additional dialysis.
International Journal of Environmental Research and Public Health, Aug 2, 2012
Methods: The present report attempts to illustrate the positive impact on the microbiological qua... more Methods: The present report attempts to illustrate the positive impact on the microbiological quality of dialysis patients over a 15-year period through the progressive implementation of state-of-the-art technological strategies and the optimization of microbiological surveillance procedures in five dialysis units in Sardinia. Results: Following on better microbiological, quality controls of dialysis water and improvement of procedures and equipment, a drastic improvement of microbiological water quality was observed in a total of 945 samples. The main aim was to introduce the use of microbiological culture methods as recommended by the most important guidelines. The microbiological results obtained have led to a progressive refining of controls and introduction of new materials and equipment, including two-stage osmosis and piping distribution rings featuring a greater capacity to prevent biofilm adhesion. The actions undertaken have resulted in unexpected quality improvements. Conclusions: Dialysis water should be viewed by the nephrologist as a medicinal product exerting a demonstrable positive impact on microinflammation in dialysis patients. A synergic effort between nephrologists and microbiologists undoubtedly constitutes the most effective means of preventing dialysis infections.
Journal of Nephrology, Dec 23, 2010
ABSTRACT In recent years, treatment options for secondary hyperparathyroidism (SHPT) have increas... more ABSTRACT In recent years, treatment options for secondary hyperparathyroidism (SHPT) have increased (e.g., paricalcitol, calcimimetics). To determine the impact these new treatments have on achieving K/DOQI targets, an observational, prospective survey was undertaken. Four 6-month time-spaced surveys of 2,637 patients in 28 Italian dialysis units were performed. Patient demographic information; use of vitamin D or calcimimetics; and changes in parathyroid hormone (PTH), calcium (Ca) and phosphate (P) levels were evaluated. Over the course of the survey, use of calcitriol decreased (from 62.1% at baseline to 44.5% at month 18; p<0.001), while use of paricalcitol (from 19.9% to 36.9%; p<0.001) and calcimimetics (from 6.4% to 10.8%; p<0.001) increased. This was associated with a decrease in mean PTH values (from 310.3 ± 292.4 pg/mL at baseline to 279.5 ± 250.1 pg/mL at month 18; p=0.0002), while mean Ca and P remained steady. The percentage of patients achieving K/DOQI ranges for PTH (from 26.8% at baseline to 32.0% at month 18, p<0.001), Ca (from 50.4% at baseline to 55.9% at month 18, p<0.001) and the 3 targets combined (PTH, Ca and P; from 8.8% at baseline to 11.5% at month 18, p=0.003) significantly increased (p<0.05). Despite the introduction of newer agents, two thirds of patients did not achieve target levels. Increased awareness and newer treatment options for chronic kidney disease patients with SHPT have changed treatment policy and number of patients achieving K/DOQI target levels in Italy. However, the majority of patients did not meet the target ranges, suggesting that new drugs and strategies are still warranted for optimal management of SHPT in chronic kidney disease.
Blood Purification, 2006
Aim: The purpose of this study was to optimize the operative and analytical methodologies to a mo... more Aim: The purpose of this study was to optimize the operative and analytical methodologies to a more exact determination of intradialytic kinetics of the phosphates (P) tested in hemodialysis (HD) and in on-line hemodiafiltration with endogenous reinfusion (HFR – Hemo Filtrate Reinfusion). Methods: The mass balance measurements of urea and P were carried out in 18 clinically stable HD patients. The effective blood flow (Qb) was measured with a Transonic® monitor. The plasma was deproteinized with 10% trichloroacetic acid to prevent breakdown of the proteins and the consequent pseudohyperphosphatemia. Subsequently the supernatant containing the ultrafiltrable phosphates was made to react with a solution of ammonium molybdate for a spectrophotometric reading. Results: The mean urea mass transfer in HD was 16.9 g/session and in HFR 15.4 g/session. The mean P mass transfer in HD was 726 mg/session and in HFR 679 mg/session. Nevertheless, in HFR a significant difference was verified between the clearances of P, between the plasma water side (122.4 ± 30.8 ml/min) and the dialysate side (105.9 ± 19.4 ml/min). Conclusion: As far as the P mass transfer is concerned, the data obtained is able to be superimposed with that described in the literature during HD, while in HFR it is possible to hypothesize a high efficiency, thanks to an increased output of P in relation to the phenomenon of adsorption which, although is limited, contributes to the transfer of the total mass. Based on this study and re-examining the literature on P kinetics, there is space for methodological improvement both on the operating front with careful determination of the effective Qb, and on the chemical front overcoming the inaccuracy of automatic analyzers in determining the plasma P owing to possible overestimation of phosphatemia and poor sensitivity in measuring the lower levels of P present in the dialysate and/or ultrafiltrate.
Clinical nutrition ESPEN, Jun 1, 2023
European Journal of Epidemiology, 1992
To study the spread of human immunodeficiency virus type 1 (HIV-1) in Sardinia, we conducted a mu... more To study the spread of human immunodeficiency virus type 1 (HIV-1) in Sardinia, we conducted a multicentre prospective study of the prevalence of antibody to HIV-1 (anti-HIV-1) in various populations during 1985-1989. The highest anti-HIV-1 prevalence (61.4%) was found in intravenous drug users. Anti-HIV-1 was found in 32% of haemophiliacs, 4.2% of thalassemics and less than 1% in the other groups. We conclude that control ofHIV infection in Sardinia will require a major expansion of prevention and treatment programs for drug addiction.
Nephron, 2018
Lack of adequate management of chronic kidney disease (CKD) often results in delayed diagnosis an... more Lack of adequate management of chronic kidney disease (CKD) often results in delayed diagnosis and inadequate treatment. This study assessed the clinical management and outcome of stages 1-5 CKD patients. Patients were prospectively followed for 3 years in 25 nephrology centers across Italy. Clinical characteristics were measured at baseline and every 6 months. Outcome measures included CKD staging, presence of comorbidities, treatment, mineral bone disorder (MBD) parameters, and patient outcomes. Of 884 enrolled patients (59.7% males, aged 66.2 ± 14.6 years), 587 (66.4%) completed the study. The majority of patients were referred by a general practitioner (44.7%) and had stage 3 or 4 CKD (40.9 and 23.8% respectively). Data reveal that 91.3% of patients had at least 1 concomitant disease, most frequently hypertension (80.1%) and dyslipidemia (42.5%); 94.6% of patients were receiving cardiovascular medication and 52.6% were receiving lipid-lowering medication. Approximately 40% of patients had proteinuria and intact parathyroid hormone levels outside the normal range. As expected, stages 4 and 5 CKD patients had a higher prevalence of proteinuria (68 and 74%), MBD (59 and 88%) and anemia (28 and 73%), as well as a higher risk of hospitalization (34.3 and 51.9%) and need for dialysis (69.5 and 70%). The overall probability of survival over 36 months was 90.6%. This is the first Italian prospective study performed with a large cohort of CKD patients over a 3-year period. Considering the multifactorial burden of diseases associated with CKD patients, the need for greater attention to CKD and related disorders is paramount.
Abstract: Methods: The present report attempts to illustrate the positive impact on the microbiol... more Abstract: Methods: The present report attempts to illustrate the positive impact on the microbiological quality of dialysis patients over a 15-year period through the progressive implementation of state-of-the-art technological strategies and the optimization of microbiological surveillance procedures in five dialysis units in Sardinia. Results: Following on better microbiological, quality controls of dialysis water and improvement of procedures and equipment, a drastic improvement of microbiological water quality was observed in a total of 945 samples. The main aim was to introduce the use of microbiological culture methods as recommended by the most important guidelines. The microbiological results obtained have led to a progressive refining of controls and introduction of new materials and equipment, including two-stage osmosis and piping distribution rings featuring a greater capacity to prevent biofilm adhesion. The actions undertaken have resulted in unexpected quality improve...
Giornale italiano di nefrologia : organo ufficiale della Societa italiana di nefrologia, 2017
Introduction Epidemiological data relating to the prevalence and incidence of Fabry disease (FD) ... more Introduction Epidemiological data relating to the prevalence and incidence of Fabry disease (FD) and other Lysosomal Storage diseases (LSDs) are largely underestimated and not yet well known. Distribution of the disease varies according to geographical area and to ethnic origin. Heterozygous females are also at risk of contracting severe and multi-symptomatic forms of FD. Aim To demonstrate the results obtained in outpatient surgeries situated in an area comprising 319,340 inhabitants. Methods Out of a total of 2710 nephrologist visits, 150 patients with suspected FD (73 undergoing dialysis and 77 conservative management) were selected. The relatives of one female patient on dialysis who had tested positive were investigated and a further 11 patients thus identified (total: 4 males and 7 females) within a micro-area of 21,822 inhabitants, i.e. a prevalence rate of one positive case every 1,818 inhabitants. These data relate to the first 18 months of screening. Conclusions In the fie...
The International Journal of Artificial Organs, 2006
Aim The purpose of the study was to examine the effect of hemodiafiltration with endogenous reinf... more Aim The purpose of the study was to examine the effect of hemodiafiltration with endogenous reinfusion (HFR) compared to hemodialysis (HD) on 28 uremic patients with secondary hyperparathyroidism (2HPT) but positively selected for good and stable control of phosphatemia in order to evaluate the independent effects of dialysis treatments on bone turnover metabolism. Methods: The study was divided into 3 periods of observation: a) HD for three months; b) HFR for three months; c) HFR for a further 3 months. We analysed the trend of: whole PTH, 1–84 PTH, 7–84 PTH, alkaline phosphatase and its bone isoenzyme, total and ionised calcium, phosphatemia, dose of phosphate binder agents, β2-microglobulin, CRP. All the variations found were evaluated through mean values ± SD, t-tests, multivariate analysis. Results We observed a deceleration in bone turnover characterized by a reduction of the total and bone alkaline phosphatase (IU/mL) from 92.3 ± 82.8 and 35.8 ± 49.8 at the end of HD to 63.4 ...
Nephrology Dialysis Transplantation, 2014
Introduction and Aims: Whole body bioimpedance spectroscopy (wBIS) has become a standard method t... more Introduction and Aims: Whole body bioimpedance spectroscopy (wBIS) has become a standard method to measure extracellular volume (ECV) in dialysis patients. However, the accuracy of wBIS can be influenced by redistribution of fluid within body compartments, since electrical resistance is not uniformly distributed between the trunk and limbs. This bio-physical reality affects resistance and leads to inaccuracy in MP391
Nephrology Dialysis Transplantation, 2012
Introduction and Aims: Blood uremic toxin measurements are presumed to reflect extracellular flui... more Introduction and Aims: Blood uremic toxin measurements are presumed to reflect extracellular fluid, on the assumption of a uniform distribution between its two compartments, plasma and interstitial fluid (ISF). ISF is however separated from plasma by microvascular pores; toxins may not necessarily circulate "freely". Interstitial uremic composition may be particularly important due to proximity to cell metabolism, and a much larger, often expanded ISF volume in CKD. Little is known about ISF composition in CKD, owing to the difficulty of sampling the compartment. This study aimed to extract ISF and study its uremic composition in CKD patients, in steady states and during dialysis, in comparison to plasma. Methods: A flow-variation microdialysis technique was modified and adapted to simultaneously sample subcutaneous ISF of urea, creatinine, phosphate and urate in CKD patients during, and off haemodialysis (HD). ISF concentrations of these toxins were compared to their plasma levels. Metabolomic and proteomic analyses of were performed on contemporaneous ISF and plasma samples, to characterise their uremic profiles. A novel microneedle was also developed and tested as a new means of sampling ISF in CKD patients. Results: Microdialysis was performed on 24 subjects (4 controls, 13 CKD non HD, 7 HD). Although a good correlation was seen between plasma and ISF urea (r=0.98), creatinine (r=0.94), phosphate (r=0.74) and urate (r=0.82), paired analysis of the whole group showed significant differences between ISF and plasma for urea (p=0.01), creatinine (p=0.02) and urate (p=0.03), with slightly lower individual ISF levels. During HD, the ISF toxin decay curves lagged behind their plasma counterparts in most patients, indicating a disharmony between plasma and ISF toxin clearances. Metabolomics revealed over 6000 metabolites in ISF, with 33 peaks consistent with known small and protein-bound uremic toxins, and several unidentified peaks occurring more in ISF than plasma, and vice-versa. Larger hydrophobic metabolites like sphingolipids did not seem to circulate freely between the two compartments. Proteomics identified 354 proteins in ISF, with the uremic toxins beta-2 microglobulin, cystatin C and complement factor D seen in ISF, but not in plasma of some patients, and several others exhibiting a compartmental behaviour. The novel microneedles were successful in painlessly extracting ISF in 68.8% of oedematous CKD patients. Conclusions: ISF is toxin rich, ideal for metabolomic and proteomic research in uremia, and may reveal earlier accumulation of toxins and possibly a sequestration of some larger toxins within the compartment. Even small toxins may show a differential compartmental distribution, enhanced by dialysis. Microneedles show great promise in minimally invasively sampling ISF, and may bridge the gap to better understanding of ISF uremic composition, with a likely significant impact on treatment delivery in CKD, and the assessment of its efficacy.
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Papers by Piergiorgio Bolasco