Browsing by Author "Powe, Neil R."

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    A Metabolomics Approach to Identify Metabolites Associated With Mortality in Patients Receiving Maintenance Hemodialysis
    (Elsevier, 2024-06-29) Al Awadhi, Solaf; Myint, Leslie; Guallar, Eliseo; Clish, Clary B.; Wulczyn, Kendra E.; Kalim, Sahir; Thadhani, Ravi; Segev, Dorry L.; McAdams DeMarco, Mara; Moe, Sharon M.; Moorthi, Ranjani N.; Hostetter, Thomas H.; Himmelfarb, Jonathan; Meyer, Timothy W.; Powe, Neil R.; Tonelli, Marcello; Rhee, Eugene P.; Shafi, Tariq; Medicine, School of Medicine
    Introduction: Uremic toxins contributing to increased risk of death remain largely unknown. We used untargeted metabolomics to identify plasma metabolites associated with mortality in patients receiving maintenance hemodialysis. Methods: We measured metabolites in serum samples from 522 Longitudinal US/Canada Incident Dialysis (LUCID) study participants. We assessed the association between metabolites and 1-year mortality, adjusting for age, sex, race, cardiovascular disease, diabetes, body mass index, serum albumin, Kt/Vurea, dialysis duration, and country. We modeled these associations using limma, a metabolite-wise linear model with empirical Bayesian inference, and 2 machine learning (ML) models: Least absolute shrinkage and selection operator (LASSO) and random forest (RF). We accounted for multiple testing using a false discovery rate (pFDR) adjustment. We defined significant mortality-metabolite associations as pFDR < 0.1 in the limma model and metabolites of at least medium importance in both ML models. Results: The mean age of the participants was 64 years, the mean dialysis duration was 35 days, and there were 44 deaths (8.4%) during a 1-year follow-up period. Two metabolites were significantly associated with 1-year mortality. Quinolinate levels (a kynurenine pathway metabolite) were 1.72-fold higher in patients who died within year 1 compared with those who did not (pFDR, 0.009), wheras mesaconate levels (an emerging immunometabolite) were 1.57-fold higher (pFDR, 0.002). An additional 42 metabolites had high importance as per LASSO, 46 per RF, and 9 per both ML models but were not significant per limma. Conclusion: Quinolinate and mesaconate were significantly associated with a 1-year risk of death in incident patients receiving maintenance hemodialysis. External validation of our findings is needed.
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    Potential Effects of Elimination of the Black Race Coefficient in eGFR Calculations in the CREDENCE Trial
    (Wolters Kluwer, 2022) Charytan, David M.; Yu, Jie; Jardine, Meg J.; Cannon, Christopher P.; Agarwal, Rajiv; Bakris, George; Greene, Tom; Levin, Adeera; Pollock, Carol; Powe, Neil R.; Arnott, Clare; Mahaffey, Kenneth W.; CREDENCE study investigators; Medicine, School of Medicine
    Background and objectives: The effect of including race in the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation on screening, recruitment, and outcomes of clinical trials is unclear. Design, setting, participants, & measurements: The inclusion and outcomes of participants in the Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) trial, which randomized individuals with type 2 diabetes and CKD to canagliflozin or placebo, were evaluated after calculating eGFR using the 2009 CKD-EPI creatinine equation with and without a race-specific coefficient or the 2021 CKD-EPI creatinine equation. Treatment effects were estimated using proportional hazards models and piecewise linear mixed effects models for eGFR slope. Results: Of 4401 randomized participants, 2931 (67%) were White participants, 224 (5%) were Black participants, 877 (20%) were Asian participants, and 369 (8%) participants were other race. Among randomized participants, recalculation of screening eGFR using the 2009 equation without a race-specific coefficient had no effect on the likelihood of non-Black participants meeting inclusion criteria but would have excluded 22 (10%) randomized Black participants for eGFR<30 ml/min per 1.73 m2. Recalculation with the 2021 equation would have excluded eight (4%) Black participants for low eGFR and one (0.4%) Black participant for eGFR≥90 ml/min per 1.73 m2, whereas 30 (0.7%) and 300 (7%) non-Black participants would have been excluded for low and high eGFR, respectively. A high proportion (eight of 22; 36%) of end points in Black participants occurred in individuals who would have been excluded following recalculation using the race-free 2009 equation but not when recalculated with the 2021 equation (one of eight; 13%). Cardiovascular and kidney treatment effects remained consistent across eGFR categories following recalculation with either equation. Changes in estimated treatment effects on eGFR slope were modest but were qualitatively larger following recalculation using the 2021 equation. However, the effect of canagliflozin on chronic change in eGFR was attenuated by 7% among Black participants and increased 6% in non-Black participants. Conclusions: In the CREDENCE trial, eGFR recalculation without the race-specific coefficient had small but potentially important effects on event rates and the relative proportion of Black participants without substantially changing efficacy estimates.
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    Prevalence and Persistence of Uremic Symptoms in Incident Dialysis Patients
    (ASN, 2020-02-01) Rhee, Eugene P.; Guallar, Eliseo; Hwang, Seungyoung; Kim, Noori; Tonelli, Marcello; Moe, Sharon M.; Himmelfarb, Jonathan; Thadhani, Ravi I.; Powe, Neil R.; Shafi, Tariq; Medicine, School of Medicine
    Background Uremic symptoms are major contributors to the poor quality of life among patients on dialysis, but whether their prevalence or intensity has changed over time is unknown. Methods We examined responses to validated questionnaires in two incident dialysis cohort studies, the Choices for Health Outcomes in Caring for ESRD (CHOICE) study (N=926, 1995–1998) and the Longitudinal United States/Canada Incident Dialysis (LUCID) study (N=428, 2011–2017). We determined the prevalence and severity of uremic symptoms—anorexia, nausea/vomiting, pruritus, sleepiness, difficulty concentrating, fatigue, and pain—in both cohorts. Results In CHOICE and LUCID, respectively, mean age of the participants was 58 and 60 years, 53% and 60% were male, and 28% and 32% were black. In both cohorts, 54% of the participants had diabetes. Median time from dialysis initiation to the symptoms questionnaires was 45 days for CHOICE and 77 days for LUCID. Uremic symptom prevalence in CHOICE did not change from baseline to 1-year follow-up and was similar across CHOICE and LUCID. Baseline symptom prevalence in CHOICE and LUCID was as follows: anorexia (44%, 44%, respectively), nausea/vomiting (36%, 43%), pruritus (72%, 63%), sleepiness (86%, 68%), difficulty concentrating (55%, 57%), fatigue (89%, 77%), and pain (82%, 79%). In both cohorts, >80% of patients had three or more symptoms and >50% had five or more symptoms. The correlation between individual symptoms was low (ρ<0.5 for all comparisons). In CHOICE, no clinical or laboratory parameter was strongly associated with multiple symptoms. Conclusions The burden of uremic symptoms among patients on dialysis is substantial and has not changed in the past 15 years. Improving quality of life will require identification of the factors that underlie the pathogenesis of uremic symptoms and better ways of removing the toxins that are responsible.