Effect of race and ethnicity on renal transplant referral
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BACKGROUND: Multiple studies have revealed disparity in renal healthcare access and outcomes in racial/ethnic minorities with the socioeconomic status explaining the majority but not all of the disparity. We wanted to determine if racial/ethnic disparities existed at the first step toward renal transplantation, the renal transplant referral process. MATERIALS AND METHODS: A cohort of 200 adult end-stage renal disease patients was followed retrospectively for 2 years from January 2016 to February 2018. The study exposure was based on self-declared race/ethnicity of the patients, who were categorized as Black, White, and Hispanic. The study outcome was based on medical team patient evaluation and consisted of the patients who refused referral, who were not referred, and who were referred for transplant. Medical and demographic factors collected were age, gender, socioeconomic status, hemoglobin A1c ≥ 7, body mass index ≥ 40, left ventricular ejection fraction ≤ 40%, the presence of coronary or peripheral arterial disease, albumin level, history of smoking, cirrhosis, and cancer. The data were analyzed using univariate analyses and multinomial logistic regression. RESULTS: In the adjusted analysis, there was no difference in the likelihood of transplant referral between Black and White patients (OR = 0.71, 95% CI 0.22 - 2.3, p = 0.56). However, both Black (OR = 16, 95% CI 3.3 - 77, p = 0.0006) and White (OR = 22, 95% CI 3.4 - 150, p = 0.0013) patients were more likely to be referred for transplant when compared with Hispanic patients. Odds of transplant refusal were not different across race/ethnic groups. CONCLUSION: Hispanic patients are disadvantaged in the referral for renal transplant when compared to Black and White patients for reasons unclear at this time.

The Interdialytic Creatinine Rise is a novel marker of volume overload and mortality risk in hemodialysis patients.

BACKGROUND: Volume overload poses a major risk in hemodialysis patients but simple detection methods are lacking. We propose a novel marker, the Interdialytic Creatinine Rise (IDCR), readily calculated as the change in serum creatinine over time (in mg/dL/h), to assess volume overload and predict mortality risk in hemodialysis patients. METHODS: First, we calculated IDCR changes with volume in a prospective cohort of 35 hospitalized hemodialysis patients awaiting hemodialysis and 33 hospitalized patients undergoing hemodialysis every other day. Second, in a prospective cohort of 25 outpatients, IDCR cutoff values associated with hypervolemia were determined between two treatments and compared with simultaneous volume assessments by their nephrologist. Third, IDCR as a mortality predictor was studied using survival analysis in a longitudinal retrospective cohort study of 39 maintenance hemodialysis patients followed from 2012 until death or 2017. RESULTS: IDCR decreased by - 0.014 mg/dL/h each day (95%CI - 0.017,- 0.010; p < 0.001) without dialysis due to fluid volume gain and increased by 0.013 mg/dL/h (95%CI 0.008,0.017; p < 0.001) from before to after each successive hemodialysis due to fluid removal. Choosing an IDCR cutoff value of ≤0.1 had sensitivity of 82% and specificity of 79% in diagnosing volume overload with the area under the ROC curve of 0.78 (95%CI 0.59,0.97). The hazard ratio of death for each 0.01 decrease in IDCR was 1.64 (95%CI 1.31,2.07; p < 0.001). If IDCR decreased to less than 0.05 mg/dL/h, the median survival was 32 days and the odds ratio of death within 2 months was 38 (95%CI 8, 131; p < 0.001). CONCLUSIONS: In this pilot study, IDCR is shown to be a novel metric that decreases with fluid retention and increases after fluid removal. IDCR can assist clinicians in detection or exclusion of volume overload in hemodialysis patients and provide prognostic value in identifying those at high risk for death.

Autonomic effects of controlled fine particulate exposure in young healthy adults: effect modification by ozone.

BACKGROUND: Human controlled-exposure studies have assessed the impact of ambient fine particulate matter on cardiac autonomic function measured by heart rate variability (HRV), but whether these effects are modified by concomitant ozone exposure remains unknown. OBJECTIVE: In this study we assessed the impact of O(3) and particulate matter exposure on HRV in humans. METHODS: In a crossover design, 50 subjects (19-48 years of age) were randomized to 2-hr controlled exposures to filtered air (FA), concentrated ambient particles (CAPs), O(3), or combined CAPs and ozone (CAPs + O(3)). The primary end point was change in HRV between the start and end of exposure. Secondary analyses included blood pressure (BP) responses, and effect modification by asthmatic status. RESULTS: Achieved mean CAPs and O(3) exposure concentrations were 121.6 +/- 48.0 microg/m(3) and 113.9 +/- 6.6 ppb, respectively. In a categorical analysis, exposure had no consistent effect on HRV indices. However, the dose-response relationship between CAPs mass concentration and HRV indices seemed to vary depending on the presence of O(3). This heterogeneity was statistically significant for the low-frequency component of HRV (p = 0.02) and approached significance for the high-frequency component and time-domain measures of HRV. Exposure to CAPs + O(3) increased diastolic BP by 2.0 mmHg (SE, 1.2; p = 0.02). No other statistically significant changes in BP were observed. Asthmatic status did not modify these effects. CONCLUSION: The potentiation by O(3) of CAPs effects on diastolic BP and possibly HRV is of small magnitude in young adults. Further studies are needed to assess potential effects in more vulnerable populations.