Performance of creatinine-based equations to estimate glomerular filtration rate in White and Black populations in Europe, Brazil and Africa.

BACKGROUND: A new Chronic Kidney Disease Epidemiology Collaboration equation without the race variable has been recently proposed (CKD-EPIAS). This equation has neither been validated outside USA nor compared with the new European Kidney Function Consortium (EKFC) and Lund-Malmö Revised (LMREV) equations, developed in European cohorts. METHODS: Standardized creatinine and measured glomerular filtration rate (GFR) from the European EKFC cohorts (n = 13 856 including 6031 individuals in the external validation cohort), from France (n = 4429, including 964 Black Europeans), from Brazil (n = 100) and from Africa (n = 508) were used to test the performances of the equations. A matched analysis between White Europeans and Black Africans or Black Europeans was performed. RESULTS: In White Europeans (n = 9496), both the EKFC and LMREV equations outperformed CKD-EPIAS (bias of -0.6 and -3.2, respectively versus 5.0 mL/min/1.73 m², and accuracy within 30% of 86.9 and 87.4, respectively, versus 80.9%). In Black Europeans and Black Africans, the best performance was observed with the EKFC equation using a specific Q-value (= concentration of serum creatinine in healthy males and females). These results were confirmed in matched analyses, which showed that serum creatinine concentrations were different in White Europeans, Black Europeans and Black Africans for the same measured GFR, age, sex and body mass index. Creatinine differences were more relevant in males. CONCLUSION: In a European and African cohort, the performances of CKD-EPIAS remain suboptimal. The EKFC equation, using usual or dedicated population-specific Q-values, presents the best performance in the whole age range in the European and African populations included in this study.

No Race-Ethnicity Adjustment in CKD-EPI Equations Is Required for Estimating Glomerular Filtration Rate in the Brazilian Population.

BACKGROUND: Glomerular filtration rate (GFR) is usually estimated from equations using serum creatinine (sCr), with adjustment for gender, age, and race (black or nonblack). The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) is the preferred equation for adults, but it was validated for the United States population. We intended to evaluate if the race-ethnicity adjustment proposed for the sCr-based CKD-EPI equations is appropriate for the Brazilian population. METHODS: CKD outpatients had blood samples collected for determination of sCr and serum cystatin C (sCys) levels. GFR was measured (mGFR) by plasma clearance of 51Cr-EDTA and used as the reference. We compared values of mGFR and estimated GFR (eGFR) by CKD-EPI equations based on sCr (eGFRCr) and on the combination of sCr and sCys (eGFRCr-Cys). For African Brazilian patients, eGFR was calculated either without or with race adjustment. Accuracy was considered acceptable if the difference between the values of eGFR and mGFR was ≤30% (P30). RESULTS: 100 patients were enrolled (58 ± 14 years, 46% male, 39% white and 61% African Brazilian). Mean mGFR was 46.7 ± 29.2 ml/min/1.73 m2. Mean eGFRCr and eGFRCr-Cys without race adjustment were 47.8 ± 30.1 ml/min/1.73 m2 and 46.4 ± 30.3 ml/min/1.73 m2, respectively. The corresponding P30 accuracy values were 79.0% and 83.0%. In the African Brazilian subgroup, values for mean mGFR and eGFRCr either without or with race adjustment were 49.8 ± 32.2 ml/min/1.73 m2, 50.4 ± 32.7 ml/min/1.73 m2, and 58.4 ± 37.9 ml/min/1.73 m2 (P < 0.001 vs. mGFR), respectively. P30 accuracy values for eGFRCr either without or with race adjustment were 75.4% and 67.2%, respectively. CONCLUSIONS: The use of CKD-EPI equations without race-ethnicity adjustment seems more appropriate for the Brazilian population.

Troponin I at admission in the intensive care unit predicts the need of dialysis in septic patients.

BACKGROUND: In a previous study we showed that troponin I (TnI) > 0.42 ng/mL predicted the need of dialysis in a group of 29 septic patients admitted to the intensive care unit (ICU). We aimed to confirm such finding in a larger independent sample. METHODS: All septic patients admitted to an ICU from March 2016 to February 2017 were included if age between 18 and 90 years, onset of sepsis < 24 h, normal left ventricular ejection fraction, and no previous coronary or kidney diseases. TnI was measured on day 1. Patients were followed by 30 days or until death. RESULTS: A total of 120 patients were included (51% male, 74 ± 13 years old). At ICU admission, 70 patients had TnI > 0.42 ng/mL. These patients had serum creatinine slightly higher (1.66 ± 0.34 vs. 1.32 ± 0.39 mg/dL; P <  0.0001) than those with lower TnI and similar urine output (1490 ± 682 vs. 1406 ± 631 mL; P = 0.44). At the end of the follow-up period, 70.0% of the patients with lower TnI were alive in comparison with 38.6% of those with higher TnI (p = 0.0014). After 30 days, 69.3 and 2.9% of the patients with lower and higher TnI levels remained free of dialysis, respectively (p <  0.0001). In a Cox regression model, after adjustment for gender, age, Charlson comorbidity index, serum creatinine, potassium, pH, brain natriuretic peptide and urine output, TnI > 0.42 ng/mL persisted as a strong predictor of dialysis need (hazard ratio 3.48 [95%CI 1.69-7.18]). CONCLUSIONS: TnI levels at ICU admission are a strong independent predictor of dialysis need in sepsis.

Effects of citrate-enriched bicarbonate based dialysate on anticoagulation and dialyzer reuse in maintenance hemodialysis patients.

Systemic anticoagulation with unfractionated heparin is commonly used in maintenance hemodialysis (HD), but it increases the risk of bleeding complications. We investigated whether the use of citrate-enriched bicarbonate based dialysate (CD) would reduce systemic anticoagulation without compromising the efficacy of reprocessed dialyzers. This is a crossover study in which half of a total of 30 patients initially underwent HD with acetate-enriched bicarbonate based dialysate and a standard heparin dose of ∼ 100 IU/kg (Treatment A), whereas the remaining patients were treated with CD and a 30% reduced heparin dose (Treatment B). After 12 consecutive HD sessions in each treatment, the dialysate and heparin doses were reversed, then followed for another period of 12 HD sessions. The two treatment phases were split by a washout period of six HD sessions using acetate-enriched bicarbonate based dialysate and standard heparin dose. Systemic anticoagulation was higher in Treatment A. The activated partial thromboplastin time at the end of HD session was 68 ± 36 seconds in Treatment A and 47 ± 16 seconds in Treatment B (P = 0.005). Sixty-eight percent of the dialyzers remained adequate until the 12th use in Treatment A and 61% did so in Treatment B (P = 0.63). Patients had three and 24 cramps episodes during Treatment A and B, respectively (P < 0.001). Nine and 26 symptomatic intradialytic hypotension episodes were seen in Treatment A and B, respectively, (P = 0.003). In conclusion, the use of CD had a favorable effect on anticoagulation in the extracorporeal circuit in patients on maintenance HD, but it was also associated with more hypotension and cramps.

Association of ankle-arm index with inflammation and mineral bone disorder in hemodialysis patients.

BACKGROUND: Reduced ankle-arm index (AAI), inflammation and mineral bone disorder (MBD) are all associated with increased risk of death and cardiovascular complications in patients on hemodialysis (HD), but the association between them deserves clarification. OBJECTIVE: To evaluate the association between abnormal AAI with MBD and inflammation in patients on HD. METHODS: This was a cross-sectional analysis of 478 patients on hemodialysis for at least one year. The AAI was evaluated using a portable Doppler and mercury column manometer. Patients were divided into 3 groups, according to AAI (low: <0.9, normal: 0.9 to 1.3, and high: >1.3). C-reactive protein measurement was used as an inflammatory marker, whereas MBD was evaluated by calcium, phosphorus and intact parathyroid hormone levels. RESULTS: Participants were 54 (18 to 75) years old, 56% males, 17% diabetics, and had been on hemodialysis for a mean of 5 (1 to 35) years. The prevalence of low, normal and high AAI was 26.8%, 64.6% and 8.6%, respectively. Using a backward conditional logistic regression model, age (p<0.001), diabetes (p= 0.001), and C-reactive protein levels >6 mg/L (p= 0.006) were associated with the presence of low AAI, whereas male gender (p<0.001), diabetes (p= 0.001) and elevated calcium x phosphorus product (p= 0.026) were associated with high AAI. CONCLUSION: In patients on hemodialysis, the presence of diabetes was associated with both low and high AAI. The risk of having low AAI seems to be increased by aging and inflammation, whereas BMD was associated with high AAI.