Paul Tam

Hôpital du Sacré-Coeur de Montréal, Montréal, Quebec, Canada

Are you Paul Tam?

Claim your profile

Publications (23)43.28 Total impact

  • Transplantation 07/2013; 96(1):e1-e2. · 3.78 Impact Factor
  • Source
    International Journal of Endocrinology 01/2013; 2013:164103. · 2.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Widespread Al toxicity is unusual today. In 2005, Canadian peritoneal dialysis (PD) centers reported widespread hyperaluminemia in patients using dialysates from one specific manufacturer. Our objectives were to evaluate risk factors related to Al accumulation and to assess its clinical consequences in patients from 2 centers. ♢ METHODS: A retrospective closed cohort study was conducted in patients treated with PD in May 2005. A multivariate linear regression model was constructed to identify variables associated with a higher serum Al level in the exposed group at the moment of solution change. Using appropriate statistical methods, anemia and bone metabolism parameters were compared between the exposed and unexposed groups. Time to first peritonitis was estimated by the Kaplan-Meier method. ♢ RESULTS: The study cohort included 87 Al-exposed patients and 95 unexposed patients. In the exposed group, serum Al at the moment of solution change was influenced by the length of exposure to Al-containing dialysates and by PD creatinine clearance; serum Al was inversely correlated with renal creatinine clearance. No consequences of Al accumulation were observed. No difference was observed in the time to first peritonitis between patients who switched manufacturers and those who remained with the original manufacturer. ♢ CONCLUSIONS: Our results suggest that hyperaluminemia is directly related to the length and extent of exposure to Al-containing dialysates; residual renal function is protective against Al accumulation. Because the problem was detected rapidly, no clinical consequences of hyperaluminemia were observed in the study cohort.
    Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis. 08/2012;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose: To assess the technical success rate and safety of radiofrequency perforation guidewire (RF) technology for the recanalization of refractory chronic central venous occlusions in symptomatic hemodialysis patients with failed conventional endovascular methods. Methods: This single center retrospective cohort of hemodialysis patients comprised of six men (mean age 67 years, range 55 to 80) with autogenous fistulae, who had already undergone failed conventional endovascular methods. These patients underwent the RF perforation technique from December 2006 to January 2010. Results: Three patients were successfully treated using the RF perforation technique, after which they had PTFE stent grafts placed at the site of occlusion. There was no recurrence of clinical symptoms. In the remaining three patients, the procedure was terminated after multiple unsuccessful attempts. There were no complications. Conclusions: The RF perforation technique is a potential alternative technology for recanalization of refractory chronic central venous occlusions in hemodialysis patients in the setting of failed conventional endovascular recanalization techniques.
    The journal of vascular access 07/2012; · 1.02 Impact Factor
  • American Journal of Kidney Diseases 09/2011; 58(5):861-3. · 5.29 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Despite the risk of aluminum (Al) toxicity in dialysis patients, little is known about its toxicokinetics (TK) in this population. A national contamination of dialysate solutions with Al provided the opportunity to study Al TK in peritoneal dialysis (PD) patients and to better understand the influence of covariates on its disposition. Al levels in serum and dialysate as well as other laboratory values were collected prospectively from 83 PD patients after correction of Al contamination. Population TK analyses were conducted with NONMEM VI using standard model discrimination criteria. Covariate analyses were also performed using stepwise forward regression followed by backward deletion. After correction of Al exposure, serum levels declined in a biphasic manner, which was captured by the TK model. The TK of Al were best described by a 2-compartment model with linear elimination. Total creatinine clearance was a significant covariate for total clearance (CL). Mean parameter estimates for volume of central compartment (V1), CL, volume of peripheral compartment (V2), volume of distribution at steady-state (Vss), and intercompartmental clearance (Q) were 168 L, 8.99 L/day, 12 000 L, 12 168 L, and 4.93 L/day, respectively. Inter-individual variability for CL and V2 were 22.6 and 51.1%, respectively. Al distributional half-life was 8.5 days, while the terminal elimination half-life was 7.2 years. This model confirms that the large Vss reflects the widespread distribution of Al in bone, lungs, liver, and other tissues. This study describes the first population Al TK model in a large group of PD patients, which includes a covariate effect. The model confirms the extensive half-life and tissue distribution of Al in a dialysis-dependent population.
    Clinical Toxicology 08/2011; 49(7):659-63. · 2.59 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Preservation of the mesothelial cells (MCs) is crucial for longevity of the peritoneal dialysis membrane. Glucose accelerates aging of MC and we tested whether N-acetylglucosamine (NAG) has an identical effect. Replicative aging of MCs was studied during 10 passages performed every three days in cells cultured in standard medium or in medium supplemented with Glucose 30 mmol/L or NAG 30 mmol/L. Changes in population doubling time and ß-galactosidase activity were used as an index of aging and compared with other cellular parameters. Repeated passages of MC cause their aging, as reflected by prolongation of the population doubling time, increased ß-galactosidase activity, oxidative stress and release of cytokines. Healing of injured mesothelial monolayer is impaired in senescent cells. Glucose accelerates in vitro aging of MC, whereas NAG does not cause this effect. Replacement of glucose with NAG in the dialysis fluid can slow down aging of MC.
    The International journal of artificial organs 06/2011; 34(6):489-94. · 1.76 Impact Factor
  • Source
    International journal of nephrology. 01/2011; 2011:218974.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To assess the safety and effectiveness of a polytetrafluoroethylene (PTFE) encapsulated nitinol stents (Bard Peripheral Vascular, Tempe, AZ) for treatment of hemodialysis-related central venous occlusions. Study design was a single-center nonrandomized retrospective cohort of patients from May 2004 to August 2009 for a total of 64 months. There were 14 patients (mean age 60 years, range 50-83 years; 13 male, 1 female). All patients had autogenous fistulas. All 14 patients had central venous occlusions and presented with clinical symptoms of the following: extremity swelling (14%, 2 of 14), extremity and face swelling (72%, 10 of 14), and face swelling/edema (14%, 2 of 14). There was evidence of access dysfunction with decreased access flow in 36% (5 of 14) patients. There were prior interventions or previous line placement at the site of the central venous lesion in all 14 patients. Results were assessed by recurrence of clinical symptoms and function of the access circuit (National Kidney Foundation recommended criteria). Sixteen consecutive straight stent grafts were implanted in 14 patients. Average treated lesion length was 5.0 cm (range, 0.9-7 cm). All 14 patients had complete central venous occlusion (100% stenosis). The central venous occlusions were located as follows: right subclavian and brachiocephalic vein (21%, 3 of 14), right brachiocephalic vein (36%, 5 of 14), left brachiocephalic vein (36%, 5 of 14), and bilateral brachiocephalic vein (7%, 1 of 14). A total of 16 PTFE stent grafts were placed. Ten- or 12-mm-diameter PTFE stent grafts were placed. The average stent length was 6.1 cm (range, 4-8 cm). Technical (deployment), anatomic (<30% residual stenosis), clinical (resolution of symptoms), and hemodynamic (resolution of access dysfunction) success were 100%. At 3, 6, and 9 months, primary patency of the treated area and access circuit were 100% (14 of 14). This PTFE encapsulated stent graft demonstrates encouraging intermediate-term patency results for central vein occlusions. Further prospective studies with long-term assessment and larger patient populations will be required.
    CardioVascular and Interventional Radiology 11/2010; 34(5):949-57. · 2.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to examine the accuracy of the Modification of Diet in Renal Disease (MDRD) equation and the Cockcroft and Gault formula (CCrCG) in predicting total creatinine clearance achieved by residual renal function plus peritoneal dialysis in patients on chronic peritoneal dialysis. Total creatinine clearance was defined as peritoneal creatinine clearance (PCcr) plus the average of urine urea and creatinine clearances (cGFR). Correlation analysis and Bland-Altman plot were used to establish the degree of correlation and agreement between the estimations of creatinine clearance achieved by PCcr and the average of cGFR and estimated creatinine clearance based on serum creatinine by using either MDRD equation or the Cockcroft and Gault formula. In one hundred fifty-six measurements, mean clearances by [cGFR + PCcr], CCrCG and MDRD were: 7.9 ± 3.1, 10.6 ± 5.2 and 8.5 ± 4.9 ml/min/1.73 m(2), respectively. There was a good correlation between [cGFR + PCcr] and MDRD (r = 0.776, P < 0.05) and [cGFR + PCcr] and CCrCG (r = 0.735, P < 0.05). The mean MDRD was not significantly different from the mean clearance by [cGFR + PCcr] (difference 0.4 ± 2.9 ml/min/1.73 m(2), agreement limit -5.4-6.3 ml/min/1.73 m(2)). The CCrCG formula gave a larger difference from the mean [cGFR + PCcr] (2.8 ± 10.5 ml/min/1.73 m(2)) and a much wider agreement limit (-3.7-9.3 ml/min/1.73 m(2)). In male patients, MDRD formula provided an estimate of clearance that was similar to the mean [cGFR + PCcr] (7.9 ± 3.8 ml/min/1.73 m(2) vs. 8.2 ± 3.2 ml/min/1.73 m(2), respectively; difference 0.10 ± 1.9 ml/min/1.73 m(2), limits of agreement -3.9-3.7 ml/min/1.73 m(2)). By contrast, in female patients, the MDRD equation significantly overestimated the clearance (difference between mean estimated and mean measured clearance 1.4 ± 4.1 ml/min/1.73 m(2), limits of agreement -6.6-9.5 ml/min/1.73 m(2) P < 0.05). In conclusion, the GFR estimated by MDRD formula is similar to [cGFR + PCcr] especially in males. GFR by the CCrCG formula tended to overestimate the highest values of [cGFR + PCcr].
    International Urology and Nephrology 04/2010; 42(4):1085-92. · 1.33 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The mean age of patients with end-stage renal disease increases steadily. The elderly on dialysis have significant comorbidity and require extra attention to meet their dialysis, dietary, and social needs, and some may need to be treated at a long-term care facility such as a nursing home (NH). Providing dialysis and caring for elderly patients in a nursing home (NH) presents a number of challenges. Few data are available in the literature about elderly patients on peritoneal dialysis (PD) in an NH. This paper describes our experience of starting and maintaining a peritoneal dialysis program in three community-based nursing homes. RESULTS: During the period 2004-2008, after the nursing home personnel had received appropriate training, we established a PD program in three community-based nursing homes and admitted 38 patients on peritoneal dialysis. We educated 112 NH staff over the three-year period. Mean age of the patients at entry was 77.3 + or - 8.5(18.4%) were male. The main causes of end-stage renal disease were diabetes mellitus (DM) 21 (55.8%) and hypertension 13 (34.2%). Comorbid conditions included DM (27, 71.1%), hypertension (26, 68.4%), coronary artery disease (18.5%), chronic heart failure (11, 28.9%), cerebrovascular event (12, 31.6%), and cancer(3, 7.9%). The average total time on chronic peritoneal dialysis was 36.5 + or - 29.8 months, (median 31, range: 1-110 months) of which the average time in the NH program, as of the time of this report, was 18.4 + or - 13.1 months (median 15.5, range: 1-45 months). During the study period, 16 (42.1%) of the patients died, 2 (5.3%) transferred to HD, 2 (5.3%) stopped treatment, and 18 (47.4%) are still in the program. Actuarial patient survival from entry into the NH program was 89.5% at six months, 60.5% at 12 months, 39.5% at 24 months and 13.2% at 36 months. Patient survival from initiation of chronic dialysis was 89.5% at six months, 76.3% at 12 months, 63.1% at 24 months, and 39.5% at 36 months. We observed 28 episodes of peritonitis with a rate of one episode every 40.3 treatment-months. Two PD catheters had to be replaced, giving a rate of one in every 362.5 patient months. CONCLUSION: Our results with elderly patients in a nursing home show an excellent patient and technique survival and a low peritonitis rate. With appropriate training of the NH nursing staff, peritoneal dialysis could be performed successfully in these nursing homes. Successful peritoneal dialysis in a nursing home requires a close collaboration between the nursing home staff and PD dialysis unit.
    International Urology and Nephrology 02/2010; 42(2):545-51. · 1.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To compare the immediate results of ultrahigh-pressure (UHP) balloons vs. peripheral cutting balloons (PCB) for the treatment of stenoses associated with autogenous fistulas using intra-access blood flow measurements. This prospective randomized study consisted of 22 hemodialysis (HD) patients with autogenous fistulas who had decreased intra-access blood flow (<500 mL/min). All patients underwent a fistulogram and intraprocedural blood flow measurements. Patients were randomized once into two groups; one group undergoing UHP angioplasty and the second group undergoing PCB angioplasty. Randomization occurred once after the diagnostic fistulogram and each patient in each arm only underwent percutaneous transluminal angioplasty with either UHP or PCB. The study cohort consisted of 12 patients in the UHP group and 10 patients in the PCB group. Data collected included fistula anatomy, degree of stenosis, length of stenosis, balloon specifications and residual stenosis. The 22 study patients underwent 35 angioplasty procedures; 23 in the UHP group (12 patients) and 12 in the PCB group (10 patients). The technical success rate was 91%. The pre-intervention mean blood flow was 288 mL/min in the UHP group and 391 mL/min in the PCB group. The post-intervention mean blood flow was 613 mL/min in the UHP group and 606 mL/min in the PCB group. The mean increase in blood flow was 325.8 mL/min in the UHP group and 213 mL/min in the PCB group. This represents a relative mean increase in blood flow of 253% in the UHP group and 85% in the PCB group. An unpaired t-test showed there was no significant difference between the groups with respect to pre-flow, post-flow, and mean and relative mean increase in flow. There were two failures; one in the UHP group and one in the PCB group. There was one minor complication (2.8%) but no major complications. In this small group of HD patients with autogenous fistulas our comparison of UHP to the PCB demonstrated that the immediate results, as determined by measurement of intra-access blood flow, were equivalent. Further long-term follow-up will be required to determine the longevity of these results.
    The journal of vascular access 01/2010; 11(4):303-11. · 1.02 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: CKD patients referred to a renal management clinic are looked after by a multidisciplinary team whose care may improve outcome and delay the progression of kidney disease. This paper describes our experience and the results obtained in 940 patients with CKD stage 4 and 5 patients from two renal management clinics (RMC). We collected and analyzed the data from 940 patients with CKD stage 4 and 5 at the RMCs of the Toronto General Hospital (TGH), University Health Network and The Scarborough General Hospital (TSH) from January 2000 to November 2007. Inclusion criteria for the study required at least three measurements of serum creatinine over a minimum follow-up of 6 months. We calculated the change of slope of the estimated GFR by linear regression analysis. The slopes were further subdivided into five groups: improved eGFR (eGFR slope >or=+5 ml/min/year); mild improvement (slope >+1 to <+5 ml/min/year); stable (slope <+1 to >-1 ml/min/year); slow progression (i.e., deterioration; slope <-1 to >-5 ml/min/year) and rapid progression (slope >-5 ml/min/year). During a median follow-up of 1.57 year (range 0.5-8.7 year) of stage 4 patients, eGFR improved in 10.6%, showed mild improvement in 24.2%, was stable in 27.5%, showed slow progression in 28.8% and rapid progression in 8.9% of patients. During a median follow-up of 1.4 year (range 0.5-8 year) of CKD stage 5 patients, eGFR improved in only 1.3%, showed mild improvement in 4.3%, remained stable in 35.6%; showed slow progression in 19.7% and rapid progression in 39.1%. Between the two hospitals (TGH and TSH) there was a statistically significant difference in the number of visits per year for CKD stage 4 patients during the first, second and third year. However, the number of visits per year had no effect on the rate of decline. On univariate analysis, factors predicting non-progression in eGFR slope were eGFR at referral, the use of ACE inhibitors-ARBs and absence of cardiovascular disease. However, in logistic multivariate regression analysis, after adjusting for confounding factors only the eGFR at referral and ACE inhibitors-ARBs were independent factors for non-progression in eGFR. A significant percentage of CKD stage 4 patients attending a renal management clinic (RMC) showed non-progression or improvement in their kidney function. Although only few stage 5 CKD patients had improvement in their eGFR, 32% of them maintained their eGFR on conservative treatment for over 2 years delaying the initiation of dialysis.
    International Urology and Nephrology 08/2009; 41(4):977-82. · 1.33 Impact Factor
  • Source
    Peritoneal dialysis international: journal of the International Society for Peritoneal Dialysis 01/2009; 29(3):352-5. · 2.21 Impact Factor
  • Journal of Vascular and Interventional Radiology - J VASC INTERVEN RADIOL. 01/2009; 20(2).
  • [Show abstract] [Hide abstract]
    ABSTRACT: The adverse effects arising from late referral to a nephrologist of patients with chronic kidney disease (CKD) are well known. Retrospectively we examined the initial characteristics of patients referred in various stages of CKD to our nephrology division and tried to identify potential baseline factors associated with subsequent changes in estimated glomerular filtration rate (eGFR). Between September 1997 and June 2006 1,443 patients (909 male, 534 female) with CKD, with eGFRs ranging from 15 to 89 ml/min, were referred to our nephrology division and categorized using the National Kidney Foundation classification for CKD based on eGFR. The slope of eGFR change (ml/min-1/1.73/m2-1/year-1) was determined by linear regression analysis and the patients were divided into five groups: (1) significantly progressive slope (deterioration) (more negative than -5 ml/min/year); (2) mildly progressive slope (>-5 to <or=-1); (3) stable slope (>-1 to <or=+1); (4) mildly improved slope (>+1 to <or=+5), and (5) significantly improved slope (>or=+5). At the first nephrology referral, 5.8% of the patients were on CKD stage 2 (eGFR: 90-60 ml/m), 46.7% on CKD stage 3 (eGFR: 59-30 ml/m), and 47.5% on CKD stage 4 (eGFR: 29-15 ml/m) CKD. Significantly improved slope was detected in 48.2% of CKD stage 2 patients, 29.3% of CKD stage 3 patients, and only 14.7% of CKD stage 4 patients (P<0.05). Being in stage 4 or stage 3 versus being in stage 2 significantly reduced the likelihood of an improved slope in logistic regression analysis whereas age, gender, presence of hypertension, and diabetes mellitus did not reach the level of significance. Referral to a nephrology clinic can lead not only to arrest of progression of CKD but also to regression/improvement. Early referral is a positive predictive factor for improvement in eGFR, which emphasizes the importance of such referral. The previously held idea that, once established, CKD progresses invariably is not valid anymore.
    International Urology and Nephrology 05/2008; 40(3):841-8. · 1.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Glucose is commonly used as an osmotic solute in peritoneal dialysis fluids despite vast knowledge about deleterious peritoneal and systemic effects of that solute. N-acetylglucosamine (NAG) is a solute of the comparable size to glucose, with strong anti-inflammatory properties. We compared the chronic in vitro effect of both solutes on phenotype of peritoneal mesothelial cells. Experiments were performed of primary cultures of human peritoneal mesothelial cells, which were cultured over 4 weeks in medium supplemented either with glucose 45 mmol/L (GLU) or with NAG 45 mmol/L (NAG). Generation of reactive oxygen species (ROS) in cells was studied, as well as their ability to proliferate, synthesis of cytokines, fibronectin, and factors regulating peritoneal fibrinolysis. Cells cultured in the presence of glucose 45 mmol/L generated more ROS (+73% vs control, P < 0.01), whereas NAG did not stimulate generation of ROS. GLU caused hypertrophy of mesothelial cells (+53% vs control, P < 0.001) and prolonged their population doubling time (+16% vs control, P < 0.01); NAG did not cause significant changes in these parameters. Healing of mesothelial monolayer after mechanical injury was impaired in GLU treated cells: (-48% vs control, P < 0.001 and -40% vs NAG, P < 0.05). Synthesis of Il-6, vascular endothelial growth factor (VEGF), transforming growth factor beta (TGFbeta), and fibronectin was higher in GLU group as compared with control: + 86%, P < 0.001, +38%, P < 0.05, +51%, P < 0.001, +38%, P < 0.05, respectively. In the presence of NAG, these parameters were comparable with the control group, but at the same time NAG stimulated synthesis of hyaluronan: +116% versus control, P < 0.001 and + 96% versus GLU, P < 0.01. Treatment with GLU resulted in decline of tissue plasminogen activator/plasminogen activator inhibitor-1 (t-PA/PAI-1) ratio by 23% versus control, P < 0.001, whereas NAG increased that parameter by 43%, P < 0.01 versus control. Glucose, contrary to NAG, induces oxidative stress and proinflammatory and profibrotic changes in mesothelial cells. NAG seems to be more biocompatible osmotic solute than glucose.
    Translational Research 12/2007; 150(6):337-42. · 3.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Results of clinical studies suggest that peritoneal dialysis (PD) is less harmful to the residual renal function than haemodialysis. However, we have no objective data describing the potential injuring effect of PD to kidney. We studied in rats after unilateral nephrectomy changes in renal structure and function after 12 weeks exposure to standard, glucose-based PD fluid. One month after removing one kidney PD catheters were implanted in rats and during the following 12 weeks, twice a day, animals were infused with 20 ml of 3.9% glucose dialysis fluid containing high concentration of glucose degradation products. Rats not infused with the dialysis fluid served as control (CON). At the beginning and after 12 weeks of the study renal creatinine clearance, urinary excretion of albumin, N-acetyl-beta-glucosaminidase (NAG) and cytokines were measured. Concentration of malondialdehyde (MDA), advanced glycation end products (AGEs) and monocyte chemoattractant protein-1 (MCP-1) were measured in serum samples. Morphology of the kidneys was evaluated in the light microscope. After 12 weeks exposure to the dialysis fluid serum MDA, AGEs and MCP levels were increased as compared with CON by 80%, P < 0.002, 29%, P < 0.05 and 71%, P < 0.005, respectively. Renal clearance of creatinine was comparable in both groups, but urinary excretion of albumin was increased by 55% in control group and by 160% in the studied group, P < 0.001; whereas urinary excretion of NAG was not changed in control group but increased by 125% in the studied group, P < 0.01. Increase of the remnant kidney's weight was higher (+77%, P < 0.01) in the CON group, but accumulation of the extramesangial matrix in glomeruli and collagen in the peritubular space was stronger in the studied group by 69%, P < 0.0001 and 274%, P < 0.0001, respectively. Chronic exposure of rats to the glucose-based dialysis fluid causes morphological changes in the renal glomeruli similar to diabetic nephropathy. Albuminuria increases what may accelerate progression of the kidney damage.
    Nephrology Dialysis Transplantation 12/2006; 21(12):3539-44. · 3.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to assess the clinical and laboratory correlations of bone mineral density (BMD) measurements among a large population of patients on chronic peritoneal dialysis (PD). This cross-sectional, multicenter study was carried out in 292 PD patients with a mean age of 56 +/- 16 years and mean duration of PD 3.1 +/- 2.1 years. Altogether, 129 female and 163 male patients from 24 centers in Canada, Greece, and Turkey were included in the study. BMD findings, obtained by dual-energy X-ray absorptiometry (DEXA) and some other major clinical and laboratory indices of bone mineral deposition as well as uremic osteodystrophy were investigated. In the 292 patients included in the study, the mean lumbar spine T-score was -1.04 +/- 1.68, the lumbar spine Z-score was -0.31 +/- 1.68, the femoral neck T-score was -1.38 +/- 1.39, and the femoral neck Z score was -0.66 +/- 1.23. According to the WHO criteria based on lumbar spine T-scores, 19.2% of 292 patients were osteoporotic, 36.3% had osteopenia, and 44.4% had lumbar spine T-scores within the normal range. In the femoral neck area, the prevalence of osteoporosis was slightly higher (26%). The prevalence of osteoporosis was 23.3% in female patients and 16.6% in male patients with no statistically significant difference between the sexes. Agreements of lumbar spine and femoral neck T-scores for the diagnosis of osteoporosis were 66.7% and 27.3% and 83.3% for osteopenia and normal BMD values, respectively. Among the clinical and laboratory parameters we investigated in this study, the body mass index (BMI) (P < 0.001), daily urine output, and urea clearance time x dialysis time/volume (Kt/V) (P < 0.05) were statistically significantly positive and Ca x PO(4) had a negative correlation (P < 0.05) with the lumbar spine T scores. Femoral neck T scores were also positively correlated with BMI, daily urine output, and KT/V; and they were negatively correlated with age. Intact parathyroid hormone levels did not correlate with any of the BMD parameters. Femoral neck Z scores were correlated with BMI (P < 0.001), and ionized calcium (P < 0.05) positively and negatively with age, total alkaline phosphatase (P < 0.05), and Ca x P (P < 0.01). The overall prevalence of fractures since the initiation of PD was 10%. Our results indicated that, considering their DEXA-based BMD values, 55% of chronic PD patients have subnormal bone mass-19% within the osteoporotic range and 36% within the osteopenic range. Our findings also indicate that low body weight is the most important risk factor for osteoporosis in chronic PD patients. An insufficient dialysis dose (expressed as KT/V) and older age may also be important risk factors for osteoporosis of PD patients.
    Journal of Bone and Mineral Metabolism 02/2006; 24(1):79-86. · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: As peritonitis rates are declining, the rate of technique failure due to ultrafiltration failure and inadequate solute removal is becoming more important. The failure of the peritoneal membrane to provide adequate dialysis increases with longer duration on PD and correlates with the structural changes in the peritoneal membrane. The exact mechanism responsible for these structural changes is unclear. Conventional PD fluids with glucose as the osmotic agent and more importantly the glucose degradation products (GDP) generated during the heat sterilization of these solutions seems to be responsible for inducing many of these changes in the peritoneum. GDP's in addition to causing structural and functional alterations of the peritoneal cells is also a leading cause of advanced glycation end-products (AGE) production. There is evidence to suggest that the GDP's and AGE's are not limited to the peritoneal cavity and the membrane. They have been shown to get deposited in the vascular walls. In addition they also interact with receptors on endothelial cells and smooth muscle. Thus they could contribute to the vascular dysfunction similar to that seen in diabetes. Formation of GDP's can be reduced and even be avoided with the use of newer "biocompatible" solutions by sterilizing the glucose and the buffer in separate chambers. These newer solutions have been shown to have several local and systemic advantages over the conventional PD solutions. It remains to be seen whether their chronic use from the start of peritoneal dialysis will prevent the development of peritoneal damage thus allowing these patients to remain on this modality for longer periods.
    International Urology and Nephrology 02/2005; 37(2):409-18. · 1.33 Impact Factor

Publication Stats

105 Citations
43.28 Total Impact Points

Institutions

  • 2012
    • Hôpital du Sacré-Coeur de Montréal
      Montréal, Quebec, Canada
  • 2006–2012
    • The Scarborough Hospital
      Pickering, Ontario, Canada
  • 2011
    • Université de Montréal
      • Faculty of Pharmacy
      Montréal, Quebec, Canada
    • Inonu University
      Malatia, Malatya, Turkey
  • 2009
    • Peking University Third Hospital
      Peping, Beijing, China
  • 2005
    • University of Toronto
      • Division of Neurology
      Toronto, Ontario, Canada
  • 2004
    • Democritus University of Thrace
      Komotina, East Macedonia and Thrace, Greece