Daily ROX index can predict transitioning to mechanical ventilation within the next 24 h in COVID-19 patients on HFNC.

INTRODUCTION: High flow nasal cannula (HFNC) is used to prevent invasive ventilation in COVID-19-associated hypoxemia. The respiratory rate­oxygenation (ROX) index has been reported to predict failure of HFNC in patients with COVID-19 pneumonia during the intensive care unit stay when measured in first hours of therapy. However, the clinical course of ICU patients may change substantially in the first days of admission. The objective of this study was to investigate whether ROX index obtained in the first four days of ICU admission could predict the need for invasive respiratory support within the next 24 h of measurements. METHODS: A retrospective cross-sectional study was performed using a database that included adult patients with COVID-19 pneumonia treated in the ICU. Patients were followed from ICU admission and ROX index was calculated daily on HFNC. Receiver operating characteristics curves (ROCs) were performed. RESULTS: Two hundred forty-nine patients were enrolled, 48% of whom require mechanical ventilation (MV). The area under the ROC of the pooled 4-day values of the ROX index as a predictor of transition from HFNC to MV within 24 h of measurements was 0.86 (95%CI 0.83 to 0.88, P < 0.001) with a cutoff point of 4.06. CONCLUSION: In COVID-19 patients in high flow nasal cannula, daily ROX index measurements successfully predicted transition to mechanical ventilation within the next 24 h.

Prevalence and Determinants of Predialysis Dietitian Follow-Up: Results From the Brazilian Dialysis Registry.

OBJECTIVE: We aimed to evaluate the prevalence and sociodemographic determinants of predialysis dietitian follow-up in a large cohort of Brazilian dialysis patients. METHODS: We retrospectively evaluated data from all incident adult dialysis patients included in the Brazilian Dialysis Registry from January 2011 to September 2021. Predialysis dietitian follow-up was classified as present when a period more than 6 months of dietitian care was reported. Gender, age, skin color, education, body mass index, chronic kidney disease etiology, first chronic dialysis program, healthcare provider, and geographic regions were tested in logistic regression models. RESULTS: Ten thousand three hundred and eighty two patients met the inclusion criteria and 1,254 (12.1%) reported predialysis dietitian follow-up, most of them referred by a nephrologist (94.2%). The independent determinants of dietitian follow-up were older age, white skin color, higher education level, not having diabetes, living in North/Northeast and South (compared to Southeast), and having a nonpublic healthcare provider. When considered only patients under a predialysis care of a nephrologist, higher education, hemodialysis as the first dialysis modality, and living in the North/Northeast and South regions (compared with Southeast) were associated with dietitian follow-up. CONCLUSION: Predialysis dietitian follow-up for more than 6 months in a country where the public health system is the main dialysis provider is still very low. The nephrologist is pivotal for referral to dietitians but socioeconomic factors also seem to play a role in this regard.

Acute kidney injury associated to COVID-19 leads to a strong unbalance of circulant immune mediators.

BACKGROUND: Severe cases of coronavirus disease 2019 (COVID-19) have increased risk for acute kidney injury (AKI). The exacerbation of the immune response seems to contribute to AKI development, but the immunopathological process is not completely understood. OBJECTIVES: To analyze levels of circulant immune mediators in COVID-19 patients evolving with or without AKI. We have also investigated possible associations of these mediators with viral load and clinical outcomes. METHODS: This is a longitudinal study performed with hospitalized patients with moderate to severe COVID-19. Serum levels of 27 immune mediators were measured by a multiplex immunoassay. Data were analyzed at two timepoints during the follow-up: within the first 13 days of the disease onset (early sample) and from the 14th day to death or hospital discharge (follow-up sample). RESULTS: We studied 82 COVID-19 patients (59.5 ± 17.5 years, 54.9% male). Of these, 34 (41.5%) developed AKI. These patients presented higher SARS-CoV-2 viral load (P = 0.03), higher frequency of diabetes (P = 0.01) and death (P = 0.0004). Overall, AKI patients presented significantly higher and sustained levels (P < 0.05) of CCL-2, CCL-3, CCL-4, CXCL-8, CXCL-10, IFN-γ, IL-2, IL-6, TNF-α, IL-1Ra, IL-10 and VEGF. Importantly, higher levels of CCL-2, CXCL-10, IL-2, TNF-α, IL-10, FGFb, and VEGF were observed in AKI patients independently of death. ROC curves demonstrated that early alterations in CCL-2, CXCL-8, CXCL-10, IFN-γ, IL-6, IL-1Ra and IL-10 show a good predictive value regarding AKI development. Lastly, immune mediators were significantly associated with each other and with SARS-CoV-2 viral load in AKI patients. CONCLUSIONS: COVID-19 associated AKI is accompanied by substantial alterations in circulant levels of immune mediators, which could significantly contribute to the establishment of kidney injury.

Characteristics and predictors of mortality on haemodialysis in Brazil: a cohort of 5,081 incident patients.

BACKGROUND: Although Brazil has one of the largest populations on haemodialysis (HD) in the world, data regarding patients' characteristics and the variables associated with risk of death are scanty. METHODS: This is a retrospective analysis of all adult patients who initiated on maintenance HD at 23 dialysis centres in Brazil between 2012 and 2017. Patients were censored after 60 months of follow-up or at the end of 2019. RESULTS: A total of 5,081 patients were included in the analysis. The median age was 59 years, 59.4% were men, 37.5% had diabetes as the cause of kidney failure. Almost 70% had a central venous catheter (CVC) as the initial vascular access, about 60% started dialysis in the hospital, and fluid overload (FO) by bioimpedance assessment was seen in 45% of patients. The 60-month survival rate was 51.4%. In the Cox regression analysis, being older (P<0.0001), starting dialysis in the hospital (P=0.016), having diabetes as the cause of kidney failure (P=0.001), high alkaline phosphatase (P=0.005), CVC as first vascular access (P=0.023), and FO (P<0.0001) were associated with higher death risk, whereas higher body mass index (P=0.015), haemoglobin (P=0.004), transferrin saturation (P=0.002), and serum albumin (P<0.0001) were associated with better survival. The same variables, except initial CVC use (P=0.14), were associated with death risk in an analysis of subdistribution proportional hazards ratio including the competing outcomes. CONCLUSIONS: The present study gives an overview of a large HD population in a developing country and identifies the main predictors of mortality, including some potentially modifiable ones, such as unplanned initiation of dialysis in the hospital and fluid overload.

Inspiratory Muscle Training With an Electronic Resistive Loading Device Improves Prolonged Weaning Outcomes in a Randomized Controlled Trial.

OBJECTIVES: To test if the use of an inspiratory muscle training program with an electronic resistive loading device is associated with benefits as to muscle strength, weaning, and survival in the ICU. DESIGN: Prospective randomized controlled trial. SETTINGS: Study conducted at the ICU of a Navy's hospital, Rio de Janeiro, Brazil, from January 2016 to September 2018. PATIENTS: Tracheostomized patients (18-86 yr) on prolonged weaning. INTERVENTIONS: Participants were assigned to inspiratory muscle training (intervention group) or a traditional T-piece protocol (control group). In the inspiratory muscle training group, participants underwent training with an electronic inspiratory training device (POWERbreathe K-5; Technologies Ltd, Birmingham, United Kingdom). MEASUREMENTS AND MAIN RESULTS: Changes in respiratory muscle strength and rates of ICU survival and weaning success were compared between groups. Forty-eight participants in the inspiratory muscle training group and 53 ones in the control group were included in the final analysis. The inspiratory muscle training was associated with a substantially higher gain on muscle strength as assessed by the maximal inspiratory pressure (70.5 [51.0-82.5] vs -48.0 cm H2O [36.0-72.0 cm H2O]; p = 0.003) and the timed inspiratory effort index (1.56 [1.25-2.08] vs 0.99 cm H2O/s [0.65-1.71 cm H2O/s]; p = 0.001). Outcomes at the 60th day of ICU were significantly better in the intervention group regarding both survival (71.1% vs 48.9%; p = 0.030) and weaning success (74.8% vs 44.5%; p = 0.001). CONCLUSIONS: The use of an inspiratory muscle training program with an electronic resistive loading device was associated with substantial muscle strength gain and positive impacts in two very relevant clinical outcomes: the rates of ICU survival and successful weaning.

Association between extracellular volume control and survival in patients on short daily haemodialysis.

BACKGROUND: Fluid overload (FO) assessed by bioimpedance spectroscopy (BIS) is associated with higher mortality risk in maintenance haemodialysis (HD). The aim was to assess if a better management of FO through short daily haemodialysis (SDHD) could improve survival. METHODS: Retrospective analysis of patients who were on HD 3 sessions/week for at least 3 months and shifted to in-centre SDHD (5 or 6 sessions/week, 2 to 3 h/session) between July 2012 and June 2016 at 23 dialysis units in Brazil. The 12-month risk of death was analysed according to the predialysis hydration status measured before and 6 months after initiation of SDHD. Predialysis hydration status was considered adequate when FO ≤15% of extracellular volume. RESULTS: A total of 297 patients on SDHD were included in the analysis. Their median age was 57 (IQR 45-67) years, 62% were males, 44% diabetics, 57% on 6 dialysis sessions/week, with a median session duration of 130 (IQR 120-150) minutes. BIS assessment at initiation of the SDHD regimen was performed in 220 patients and FO > 15% was found in 46.4%. Twelve-month survival rates for those with FO ≤15 and > 15% before initiating SDHD were 87.4 and 88.0%, respectively (P = 0.92). BIS analysis when completing 6 months on SDHD were available for 229 patients, 26.6% with FO > 15%. The survival rates for the next 12 months (from the 6th to the 18th month of follow-up) for those with FO ≤15 and > 15% were 91.0 and 72.0%, respectively (P = 0.0006). In a Cox regression model, after adjustment for demographic, clinical and laboratory variables, FO ≤ 15% persisted associated with a lower mortality risk (hazard ratio 0.34, 95%CI 0.13-0.87). CONCLUSIONS: Moving from conventional HD to SDHD was associated with better control of excessive extracellular volume. Patients who reached or maintained predialysis fluid overload ≤15% after initiating SDHD presented a lower risk of death.

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.

Evaluation of a new index of mechanical ventilation weaning: the timed inspiratory effort.

PURPOSE: The performance of most indices used to predict ventilator weaning outcomes remains below expectation. The purpose of this study was to evaluate a new weaning index, the timed inspiratory effort (TIE) index, which is based on the maximal inspiratory pressure and the occlusion time required to reach it. METHODS: This observational prospective study included patients undergoing mechanical ventilation. Patients ready to be weaned had their TIE index and 6 previously reported indices recorded. The primary end point was the overall predictive performance of the studied weaning indices (area under the receiver operating characteristic curves [AUCs]). The secondary end points were sensitivity, specificity, positive predictive value, and negative predictive value. P values <.05 were considered significant. RESULTS: From the 128 initially screened patients, the 103 patients selected for the study included 45 women and 58 men (mean age 60.8 ± 19.8 years). In all, 60 patients were weaned, 43 were not weaned, and 32 died during the study period. Tracheotomy was necessary in 61 patients. The mean duration of mechanical ventilation was 17.5 ± 17.3 days. The AUC of 3 weaning predictors (the TIE index, the integrative weaning index, and the frequency-to-tidal volume [f/Vt] ratio index) was higher than the other indices. The TIE index had the largest AUC. CONCLUSION: The TIE index performed better than the best weaning indices used in clinical practice.

Effects of renal denervation with a standard irrigated cardiac ablation catheter on blood pressure and renal function in patients with chronic kidney disease and resistant hypertension.

AIMS: Evaluation of the safety and efficacy of renal denervation with a standard irrigated cardiac ablation catheter (SICAC) in chronic kidney disease (CKD) patients with refractory hypertension. METHODS AND RESULTS: Twenty-four patients were included and treated with a SICAC. Denervation was performed by a single operator following the standard technique. Patients included with CKD were on stages 2 (n = 16), 3 (n = 4), and 4 (n = 4). Data were obtained at baseline and monthly until 180th day of follow-up. Baseline values of blood pressure (mean ± SD) were 186 ± 19 mmHg/108 ± 13 mmHg in the office, and 151 ± 18 mmHg/92 ± 11 mmHg by 24 h ambulatory blood pressure monitoring (ABPM). Office blood pressure values at 180th day after the procedure were 135 ± 13 mmHg/88 ± 7 mmHg (P < 0.0001, for both comparisons). The mean ABPM decreased to 132 ± 15 mmHg/85 ± 11 mmHg at the 180th day after the procedure (P < 0.0001 for systolic and P = 0.0015 for diastolic). Estimated glomerular filtration (mean ± SD) increased from baseline (64.4 ± 23.9 mL/min/1.73 m(2)) to the 180th day (85.4 ± 34.9 mL/min/1.73 m(2), P < 0.0001) of follow-up. The median urine albumin:creatinine ratio decreased from baseline (48.5, IQR: 35.8-157.2 mg/g) to the 180th day after ablation (ACR = 15.7, IQR: 10.3-34.2 mg/g, P = 0.0017). No major complications were seen. CONCLUSION: The procedure using SICAC seemed to be feasible, effective, and safe resulting in a better control of BP, a short-term increase in estimated glomerular filtration rate, and reduced albuminuria. Although encouraging, our data are preliminary and need to be validated in the long term.

Reducing Airway Occlusion Time Without Losing Accuracy to Predict Successful Mechanical Ventilator Liberation During the Measurement of the Timed Inspiratory Effort Index.

BACKGROUND: In 2013, a new predictor of successful mechanical ventilation liberation named timed inspiratory effort (TIE) index was devised with the normalization of the maximum inspiratory pressure (obtained within 60 s of unidirectional airway occlusion) with the time at which the value was reached. The aim of this study was to verify whether the presence of a sequence of a certain number of inspiratory effort values between 30-60 s > 1.0 cm H2O/s could predict weaning success in a performance comparable to the TIE index. METHODS: This was a retrospective observational study using 4 databases of previous studies on the TIE index. All patients receiving mechanical ventilation for ≤ 24 h were eligible. Liberation from mechanical ventilation-extubation decisions was made based on performance with spontaneous breathing trials. P < .05 was considered significant. The performance of the TIE index was evaluated by calculating the area under the receiver operating characteristics (AUROC) curve. RESULTS: From 349 eligible patients, 165 subjects were selected for analysis. The AUROC for the TIE index in the studied sample was 0.92 (95% CI 0.87-0.97, P < .001). A sequence of ≤ 4 inspiratory efforts > 1.0 cm H2O/s was found in 51.5% of the subjects, with successful ventilatory liberation occurring in 95.3%. The highest specificity values belonged to the sequence of ≤ 4 and ≤ 5 inspiratory efforts > 1.0 cm H2O/s; the highest positive predictive value and positive likelihood ratio belonged to the sequence of ≤ 4 inspiratory efforts > 1.0 cm H2O/s. The mean time that could have been spared if the procedure were interrupted after the first sequence of 4 inspiratory efforts > 1.0 cm H2O/s was 23 ± 3 s. CONCLUSIONS: The presence of a sequence of ≤ 4 inspiratory efforts > 1.0 cm H2O/s during the TIE index measurement was a reliable predictor of weaning success, which could allow timely interruption of the procedure and entail a substantial reduction in airway occlusion time.

Sex-specific differences in a large cohort of Brazilian incident dialysis patients over 12 years: A retrospective study.

OBJECTIVE: Sex-specific differences in the epidemiology of chronic kidney disease, such as higher prevalence of women on pre-dialysis and men on chronic dialysis treatment, have been reported worldwide. In this regard, data from non-high-income countries are scarce. We aimed to compare the demographic, clinical, and dialysis characteristics of incident dialysis patients, both men and women, in a large cohort of Brazilian patients over a 12-year period. METHODS: This was a multicentric retrospective cohort study coordinated by the Brazilian Society of Nephrology. The study included all adult incident dialysis patients in the Brazilian Dialysis Registry from January 2011 to December 2022. The variables studied encompassed age, skin color, education, CKD etiology, predialysis nephrologist care, dialysis characteristics, and geographic region. Additionally, the sample was analyzed for each of the three 4-year periods over the 12 years of data collection. RESULTS: A total of 24,632 incident dialysis patients were included. Men were 59.1% of the dialysis population, remaining stable over the three 4-year periods. Besides other differences, women started dialysis younger (58.5 ± 16.2 years vs 59.5 ± 14.4 years; p < 0.001), had a lower educational level (less than 8 years at school: 54% vs 44%; p < 0.001), received more predialysis nephrologist care (46.2% vs 44.2%; p = 0.04), and had a higher prevalence of peritoneal dialysis (4.4% vs 3.5%; p = 0.03). CONCLUSION: We consistently observed a higher prevalence of men on dialysis and differences in demographic, clinical, and dialysis characteristics. The underlying reasons for these sex differences still necessitate further clarification.

Brazilian Dialysis Survey 2022.

INTRODUCTION: The Brazilian Dialysis Survey (BDS) is an annual national survey about patients on chronic dialysis that contributes to health policies. OBJECTIVE: To report the 2022 epidemiological data from the BDS of the Brazilian Society of Nephrology (BSN). METHODS: A survey was carried out in Brazilian chronic dialysis centers using an online questionnaire that included clinical and epidemiological aspects of patients on chronic dialysis, dialysis therapy data, and dialysis center characteristics. RESULTS: Overall, 28% (n = 243) of the centers answered the questionnaire. In July 2022, the estimated total number of patients on dialysis was 153,831. The estimated prevalence and incidence rates of patients per million population (pmp) were 758 and 214, respectively. Of the prevalent patients, 95.3% were on hemodialysis (HD, 4.6% of these on hemodiafiltration) and 4.7% on peritoneal dialysis (PD). Only 1.3% of patients were not vaccinated against COVID-19. The prevalence of anemia (Hb < 10g/dL) was 27% and hyperphosphatemia (P > 5.5mg/dL) reached 30%. The estimated overall crude annual mortality rate was 17.1%. CONCLUSIONS: The absolute number and prevalence rate of patients on chronic dialysis continue to increase. A growing number of patients were receiving hemodiafiltration. The mortality rate decreased, probably due to the end of COVID-19 pandemic. The conclusions were drawn in the context of relatively low voluntary participation, which imposed methodological limitations on our estimates.

Comparison of 1-year survival between patients initiating chronic hemodialysis under public and private health insurance: register-based data analysis from Brazil.

PURPOSE: Brazil has one of the world's highest numbers of patients on hemodialysis (HD). Most dialysis centers are private and perform HD for patients with private and public health insurance. We compared 1-year survival between patients initiating chronic HD with public and private health insurance. METHODS: This is an HD register-based retrospective cohort. Adult patients starting HD from January 2011 to December 2021 were included. Survival analysis was stratified according to the period entered in the HD register. Multivariate Cox regression focused on 1-year survival differences between private and public patients. RESULTS: In the final sample (n = 5114), 68.5% of participants had public and 31.3% to private health insurance, with overall 1-year survival of 92.8% and 89.9%, respectively (p = 0.002). Crude analysis showed a slightly higher survival rate among patients with public health insurance than those with private health insurance (91 vs. 87%, p = 0.030) in the first period (2019-21). However, the adjusted hazard ratio (HR) did not remain significantly higher for patients with private health insurance compared to those with public health insurance (HR = 1.07; 95% CI 0.80-1.41; p = 0.651), even after propensity score matching of the groups by several baseline features. CONCLUSION: Brazilian chronic HD patients funded by either private health plans or the public system have a similar 1-year mortality risk after controlling for several sociodemographic and clinical parameters.

Post-discharge all-cause mortality in COVID-19 recovered patients hospitalized in 2020: the impact of chronic kidney disease.

In Brazil, the COVID-19 burden was substantial, and risk factors associated with higher in-hospital mortality rates have been extensively studied. However, information on short-term all-cause mortality and the factors associated with death in patients who survived the hospitalization period of acute SARS-CoV-2 infection is limited. We analyzed the six-month post-hospitalization mortality rate and possible risk factors of COVID-19 patients in a single center in Brazil. This is a retrospective cohort study focused on a six-month follow-up. The exclusion criteria were death during hospitalization, transference to another hospital, and age under 18. We collected data from the charts of all hospitalized patients from March 2020 to December 2020 with a positive RT-PCR test for SARS-CoV-2, resulting in a sample size of 106 patients. The main outcome was death after hospitalization, whereas comorbidities and demographics were evaluated as risk factors. The crude post-hospitalization death rate was 16%. The first 30 days of follow-up had the highest mortality rate. In a Cox regression model for post-hospitalization mortality, previous chronic kidney disease (HR, 4.06, 95%CI 1.46 - 11.30) and longer hospital stay (HR 1.01, 95%CI 1.00 - 1.02) were the only factors statistically associated with death. In conclusion, a high six-month all-cause mortality was observed. Within the six-month follow-up, a higher risk of death was observed for patients who had prior CKD and longer hospital stay. These findings highlight the importance of more intensive medical surveillance during this period.

Survival of lupus patients on dialysis: a Brazilian cohort.

OBJECTIVE: Data about the survival rate of lupus patients on dialysis is controversial. The objective of this controlled prospective study was to report the survival of SLE patients undergoing dialysis and to analyse factors associated with mortality. METHODS: Twenty dialysis centres were visited between May 2003 and February 2004. Disease activity was evaluated using the SLEDAI without the renal-related parameters [non-renal (nr)SLEDAI] data collection was performed at entrance to the study. The control group consisted of haemodialysis patients without SLE matched for gender, age, dialysis modality, time on dialysis and dialysis-associated HCV infection. Patients were prospectively followed for 60 months. The Kaplan-Meier method was used to estimate survival. Associations of risk factors with mortality were tested using the Cox proportional hazards model. RESULTS: Each group was composed of 57 patients. In the multivariate analysis, only nrSLEDAI > 8 [hazard ratio (HR) 6.368; 95% CI 1.798, 22.548; P = 0.004], and urea reduction ratio (HR 0.953; 95% CI 0.917, 0.990; P = 0.014) were independently associated with mortality in lupus patients. The 5-year survival rate of the control group and the one from SLE patients with nrSLEDAI ≤ 8 (n = 51) were similar (83% and 73%, respectively) but significantly better than the one for SLE patients with nrSLEDAI > 8 (n = 6, 17%), P < 0.001. CONCLUSION: A high nrSLEDAI was strongly associated with 5-year mortality in lupus patients on dialysis.

Metabolic syndrome and associated urolithiasis in adults enrolled in a community-based health program.

BACKGROUND: Urolithiasis is a common and recurrent disease, whose prevalence rate has recently increased in parallel to obesity pandemic. OBJECTIVES: To estimate the prevalence of history of urolithiasis in a non-randomized sample of adults assisted by a community-based health program and to analyze its association with metabolic syndrome. METHODS: Cross-sectional study set in Niteroi, Rio de Janeiro, Brazil, including adults (non-diabetic hypertensives, diabetics or controls). Participants were assessed through a standardized questionnaire and underwent clinical and laboratory evaluation, including blood and urine samples. The diagnosis of metabolic syndrome was based on harmonized criteria. RESULTS: A total of 740 adults were enrolled (M: F = 0.85; 43±12 years; 30% white, and 70% non-white). Almost half of subjects (42.5%) had metabolic syndrome. The prevalence of urolithiasis in the sample was 10.1%. White skin colour, family history, and metabolic syndrome were independently associated with urolithiasis (P < 0.05). Subjects with the syndrome (excluding cases on diuretics) had more acidic urine (P = 0.014), increased natriuresis (P = 0.01) and higher uricosuria (P = 0.001) compared with non-affected ones. The prevalence of urolithiasis increased in proportion to the number of criteria for metabolic syndrome (P for trend <0.005). CONCLUSIONS: Metabolic syndrome is a modifiable factor associated with urolithiasis in a way that the frequency of positive history increases proportionally to the number of its diagnostic criteria. These findings reinforce the recent suggested link between urolithiasis and cardiovascular risk factors.

Characteristics and 1-year survival of incident patients on chronic peritoneal dialysis compared with hemodialysis:a large 11-year cohort study.

PURPOSE: Few studies have evaluated patients' characteristics and survival by dialysis modality in Brazil. We evaluated changes in dialysis modality and its survival in the country. METHODS: This is a retrospective database of a cohort with incident chronic dialysis patients from Brazil. Patients' characteristics and one-year multivariate survival risk were assessed considering dialysis modality from 2011 to 2016 and 2017 to 2021. Survival analysis was also performed on a reduced sample after adjustment using propensity score matching. RESULTS: Of the 8295 dialysis patients, 5.3% were on peritoneal dialysis (PD) and 94.7% on hemodialysis (HD). PD patients had higher BMI, schooling and the prevalence of elective dialysis starting in the first period than those on HD. In the second period, PD patients were predominantly women, non-white, from the Southeast region, and funded by the public health system, having more frequent elective dialysis starting and predialysis nephrologist follow-ups than those on HD. There was no difference in mortality comparing PD and HD (HR 0.67, 95% CI 0.39-2.42; and HR 1.17, 95% CI 0.63-2.16; first and second period, respectively). This non-significantly different survival between both dialysis methods was also found in the reduced matched sample. Higher age and non-elective dialysis initiation were associated with higher mortality. In the second period, the lack of predialysis nephrologist follow-up and living in the Southeast region increased the mortality risk. CONCLUSION: Some sociodemographic factors have changed according to dialysis modality over the last decade in Brazil. The one-year survival of the two dialysis methods was comparable.

Hemodialysis in Brazil: differences across geographic regions regarding demographics, laboratory parameters and drug prescription.

INTRODUCTION: Brazil has a vast territory divided into five geographic regions with important differences in sociodemographic indices. We aimed to present and compare socio-demographic characteristics, biochemical results, and drug prescription of patients on chronic hemodialysis (HD) treatment in the five geographic regions. METHODS: We evaluated data from the Brazilian Dialysis Registry of all adult patients undergoing chronic HD in 2021. Variables included sociodemographic characteristics, serum levels of phosphate, calcium, and albumin, hemoglobin, urea reduction rate, and prescription of phosphate binders, erythropoietin, and intravenous iron. Data from the North and Northeast regions were combined into one group. RESULTS: A total of 13,792 patients (57.9 ± 16.0 years old, 58.5% male, median HD vintage of 31 (11-66) months) from 73 dialysis centers were analyzed. Regional distribution was 59.5% in the Southeast; 21.7% in the South; 5.9% in the Midwest; and 12.9% in the North/Northeast. Sociodemographic features, biochemical results, and medication prescriptions differed across regions. The prevalence of elderly patients was lower in the Midwest and North/Northeast. The South region had the highest prevalence of hyperphosphatemia (41.2%) and urea reduction rate <65% (24.8%), while anemia and hypoalbuminemia were more prevalent in the Southeast, 32.7% and 11.6%, respectively. CONCLUSION: We found differences in socio-demographics, clinical features, and drug prescriptions across Brazilian geographic regions. Some findings reflect the socio-demographic diversity of the country, while others deserve further elucidation.

High prevalence of hyperkalemia in Brazilian chronic dialysis patients and differences across geographic regions.

INTRODUCTION: Hyperkalemia is a common multifactorial condition of people on chronic dialysis and is associated with mortality. We aimed to inform and discuss the prevalence of hyperkalemia in a large population of chronic dialysis patients in Brazil and its geographic regions. METHODS: Prevalence of hyperkalemia (serum potassium ≥6.0 mEq/L) was assessed in the Brazilian Dialysis Survey (BDS) in July 2019, an online survey of voluntary participation in which all dialysis centers registered at the Brazilian Society of Nephrology were invited. RESULTS: Approximately one-third (n=263 of 805) of the Brazilian dialysis clinics participated. The prevalence of hyperkalemia in the whole population was 16.1% (n=7,457 of 46,193; 95%CI=15.8-16.5%,), and varied from 12.1% in the North to 18.7% in the Northeast. CONCLUSION: We found a high prevalence of hyperkalemia in a large Brazilian chronic dialysis population. A nationwide investigation of risk factors, treatment options, and whether this high prevalence contributes to dialysis mortality is warranted.

Obesity and survival in a national cohort of incident hemodialysis patients: An analysis of the Brazilian Dialysis Registry.

INTRODUCTION: A phenomenon called the "obesity paradox" has consistently been reported in several cohorts of patients on chronic hemodialysis. In this setting, a higher body mass index (BMI) is paradoxically associated with better survival. This study aimed to evaluate the effect of BMI on mortality in patients undergoing chronic hemodialysis using the Brazilian Dialysis Registry. METHODS: This was a retrospective national cohort study with data on incident hemodialysis patients collected between January 2011 to December 2018. Those aged <18 or > 80 years were excluded from the study. The variables studied were the clinical and laboratory data regularly collected at the dialysis units. The variable of primary interest was BMI, represented as the median of the entire dialysis treatment and stratified into four ranges according to the World Health Organization (WHO) classification. The primary outcome was death within 4 years. Cox proportional hazards regression analysis was used to test associations with mortality. FINDINGS: The analyzed sample consisted of 5489 patients from 73 centers in five regions of the country. Of these, 5.9% were underweight, 48.3% were of normal weight, 31.0% were overweight, and 14.7% were obese. The 4-year survival rates in these BMI ranges were 58%, 70%, 75%, and 80%, respectively. The probability of survival for each BMI extract was significantly different from that in the normal-weight range (p < 0.05). In the fully adjusted Cox proportional hazard regression model, BMI > 24.9 kg/m2 remained an independent protective factor for mortality (HR: 0.76, 95% CI: 0.62-0.95, p = 0.016). DISCUSSION: In Brazil, being overweight and obese are protective factors for survival in the chronic hemodialysis population.