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Articles by M Tonelli
Total Records ( 5 ) for M Tonelli
  F. M Clement , S Klarenbach , M Tonelli , J. A Johnson and B. J. Manns

Background  Treatment of anemia in chronic kidney disease (CKD) with erythropoietin-stimulating agents (ESAs) is commonplace. The optimal hemoglobin treatment target has not been established. A clearer understanding of the health-related quality of life (HQOL) impact of hemoglobin target levels is needed. We systematically reviewed the randomized controlled trial (RCT) data on HQOL for patients treated with low to intermediate (9.0-12.0 g/dL) and high hemoglobin target levels (>12.0 g/dL) and performed a meta-analysis of all available 36-item short-form (SF-36) RCT data.

Methods  We conducted a search to identify all RCTs of ESA therapy in patients with anemia associated with CKD (1966–December 2006). Inclusion criteria were (1) 30 or more participants, (2) anemic adults with CKD, (3) epoetin (alfa and beta) or darbepoetin used, (4) a control arm, and (5) reported HQOL using a validated measure. All available SF-36 data underwent meta-analysis using the weighted mean difference.

Results  Of 231 full texts screened, 11 eligible studies were identified. The SF-36 was used in 9 trials. Reporting of these data was generally incomplete. Data from each domain of the SF-36 were summarized. Statistically significant changes were noted in the physical function (weighted mean difference [WMD], 2.9; 95% confidence interval [CI], 1.3 to 4.5), general health (WMD, 2.7; 95% CI, 1.3 to 4.2), social function (WMD, 1.3; 95% CI, –0.8 to 3.4), and mental health (WMD, 0.4; 95% CI, 0.1 to 0.8) domains. None of the changes would be considered clinically significant.

Conclusions  Our study suggests that targeting hemoglobin levels in excess of 12.0 g/dL leads to small and not clinically meaningful improvements in HQOL. This, in addition to significant safety concerns, suggests that targeting treatment to hemoglobin levels that are in the range of 9.0 to 12.0 g/dL is preferred.

  I Bhan , S. A. M Burnett Bowie , J Ye , M Tonelli and R. Thadhani

Background and objectives: Vitamin D deficiency (defined by serum levels of 25-hydroxyvitamin D) is common in patients with ESRD on hemodialysis, but risk factors are unknown. This study was conducted to determine whether routinely measured clinical and demographic parameters could identify dialysis patients who are vitamin D deficient.

Design, setting, participants, & measurements: Nine-hundred eight patients with 25-hydroxyvitamin D levels were identified from the Accelerated Mortality on Renal Replacement (ArMORR) cohort of incident U.S. dialysis patients and were divided into training (60%) and validation (40%) sets. Predictive models were generated from routinely assessed clinical and demographic data in the training set using logistic regression modeling, neural networks, and decision trees with vitamin D deficiency as the dependent variable. Models underwent progressive variable reduction to identify the simplest model that remained predictive.

Results: Seventy-nine percent of the population was vitamin D deficient (25-hydroxyvitamin D <30 ng/ml). Black race, female sex, winter season, and hypoalbuminemia (serum albumin ≤3.1 g/dl) were the strongest predictors of vitamin D deficiency. In the validation set, the presence of hypoalbuminemia and winter season increased the likelihood of vitamin D deficiency in black women (from 90% to 100%), black men (from 85% to 100%), white women (from 82% to 94%), and white men (from 66% to 92%).

Conclusions: Deficiency of 25-hydroxyvitamin D is nearly universal among patients with hypoalbuminemia initiating chronic hemodialysis in winter.

  D. J Tai , T. W Lim , M. T James , B. J Manns , M Tonelli , B. R Hemmelgarn and for the Alberta Kidney Disease Network

Background and objectives: Cardiovascular (CV) disease causes significant morbidity and mortality among the hemodialysis (HD) population. This meta-analysis was performed to determine whether angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) reduce fatal and nonfatal CV events and left ventricular (LV) mass in patients receiving HD.

Design, setting, participants, & measurements: Studies were identified by searching electronic databases, bibliographies, and conference proceedings. Two reviewers independently selected randomized controlled trials using ACEIs or ARBs compared with control among patients receiving HD. Studies were independently assessed for inclusion, quality, and data extraction. Random-effects models were used to estimate the pooled relative risk (RR) for CV outcomes and the weighted mean difference (WMD) for pooled change-from-baseline comparisons for LV mass for ACEI or ARB treated patients compared with control.

Results: Compared with control, the RR of CV events associated with ACEI or ARB use was 0.66 [95% confidence interval (CI) 0.35 to 1.25; P = 0.20]. ACEI or ARB use resulted in a statistically significant reduction in LV mass, with a WMD of 15.4 g/m2 (95% CI 7.4 to 23.3; P < 0.001).

Conclusions: Treatment with an ACEI or ARB reduced LV mass in patients receiving HD. However, their use was not associated with a statistically significant reduction in the risk of fatal and nonfatal CV events. Larger, high-quality trials in the HD population are required to determine if the effects of ACEI or ARB therapy on LV mass translate into decreased CV morbidity and mortality.

  P Ravani , P Parfrey , J MacRae , M James , R Quinn , F Malberti , G Brunori , S Mandolfo , M Tonelli , B Hemmelgarn , B Manns and B. Barrett

Background and objectives: Comparing outcomes of arteriovenous grafts and fistulas is challenging because the pathophysiology of access dysfunction and failure rate profiles differ by access type. Studying how risks vary over time may be important.

Design, setting, participants, & measurements: Longitudinal data from 535 incident hemodialysis patients were used to study the relationship between access type and access survival, without (semiparametric Cox modeling) and with specification of the underlying hazard function (parametric Weibull modeling).

Results: The hazard for failure of fistulas and grafts declined over time, becoming proportional only after 3 months from surgery, with a graft versus fistula hazard ratio of 3.2 (95% confidence interval 1.9 to 5.3; Cox and Weibull estimation) and time ratio of 0.11 (i.e., the estimated access survival time was approximately one tenth shorter in grafts; 95% confidence interval 0.04 to 0.28; Weibull estimation only). Considering the entire observation period, grafts had slower hazard decline (P < 0.001) with shorter median survival times than fistulas (8.4 versus 38.3 months; Weibull regression only).

Conclusions: Parametric models of arteriovenous access survival may provide relevant information about temporal risk profiles and predicted survival times.

  P Ruggenenti , A Perna , M Tonelli , G Loriga , N Motterlini , N Rubis , F Ledda , S Rota , A Satta , A Granata , G Battaglia , F Cambareri , S David , F Gaspari , N Stucchi , S Carminati , B Ene Iordache , P Cravedi , G Remuzzi and for the ESPLANADE Study Group

Background and objectives: This open, prospective, randomized trial aimed to assess the effects of statins in chronic kidney disease patients on optimized antiproteinuric treatment with combined angiotensin-converting enzyme inhibition and angiotensin receptor blockade.

Design, setting, participants, & measurements: After 1-month benazepril therapy followed by 1-month benazepril-valsartan combined therapy (run-in), 186 consenting patients with residual proteinuria >0.5 g/24 h were randomized to 6-month benazepril-valsartan therapy alone or combined with fluvastatin. Between-groups changes in proteinuria (primary outcome), serum lipids, and GFR were compared by ANCOVA. Analyses were blinded and by intention to treat.

Results: During the run-in, proteinuria decreased more on benazepril-valsartan than on benazepril alone. Proteinuria reduction correlated with concomitant reduction in total, LDL, and HDL cholesterol, and apolipoprotein B and apolipoprotein A levels. After randomization, median proteinuria similarly decreased from 1.2 (0.6 to 2.2) to 1.1 (0.5 to 1.7) g/24 h on fluvastatin and from 1.5 (0.8 to 2.7) to 1.0 (0.5 to 2.4) g/24 h on benazapril-valsartan therapy alone. Fluvastatin further reduced total and LDL cholesterol and apolipoprotein B versus benazepril-valsartan alone, but did not affect serum triglycerides and GFR. Treatment was well tolerated.

Conclusions: In chronic kidney disease patients with residual proteinuria despite combined angiotensin-converting enzyme inhibitor and angiotensin receptor blockade therapy, add-on fluvastatin does not affect urinary proteins, but further reduces serum lipids and is safe. Whether combined angiotensin-converting enzyme inhibitor, angiotensin receptor blockade, and statin therapy may improve cardiovascular outcomes in this high-risk population is worth investigating.

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