Dietary factors has been found to influence serum uric acid (SUA) levels. We further explored the associations between dietary and supplemental vitamin C intake and SUA in a large population-based ...study. The cross-sectional study included 6308 participants (3146 males and 3162 females) aged greater than or equal to20 years from the National Health and Nutrition Examination Survey (NHANES) 2011-2016 in the United States. The dietary vitamin C was log-transformed for statistical analysis. Hyperuricemia was defined as SUA concentrations >420 umol/L in males or >360 umol/L in females. The associations of dietary vitamin C and supplemental vitamin C with SUA levels and hyperuricemia risk were evaluated using weighted linear regression models and weighted multivariate logistic regression models, and a subgroup analysis stratified by gender was also conducted. In this large-scale database study, there was a negative association between dietary vitamin C (log transformed) and SUA levels in US adults (beta = -7.27, 95% CI: -11.58, -2.97). The inverse relationship existed among males but not females (P for interaction = 0.02). There was inverse correlation between dietary vitamin C (log transformed) and hyperuricemia risk (OR = 0.68, 95% CI: 0.57, 0.81), especially in males compared to females determined through an interaction test (P = 0.04). There were no associations between supplemental vitamin C and SUA levels (beta = 1.00 (95% CI: -4.44, 6.44) or hyperuricemia risk (OR = 0.98 (95% CI: 0.78, 1.24). High-dosage supplemental vitamin C (>300 mg) and hyperuricemia risk were not associated (OR = 1.04, 95% CI: 0.69, 1.56). This study demonstrated that there were negative associations between dietary vitamin C and SUA levels and hyperuricemia risk among US adults. The inverse correlations between dietary vitamin C and hyperuricemia risk were more significant in males compared to females. There were no associations between supplemental vitamin C and SUA levels or hyperuricemia risk.
Estimation and testing is studied for functional data with temporally dependent errors, an interesting example of which is the event-related potential (ERP). B-spline estimators are formulated for ...individual smooth trajectories and their population mean as well. The mean estimator is shown to be oracally efficient in the sense that it is as efficient as the infeasible mean estimator if all trajectories had been fully observed without contamination of errors. The oracle efficiency entails asymptotically correct simultaneous confidence band (SCB) for the mean function, which is useful for making inference on the global shape of the mean. Extensive simulation experiments with various time series errors and functional principal components confirm the theoretical conclusions. For a moderate-sized ERP data set, multiple comparison is made by constructing paired SCBs among four different stimuli, over three components N450, N1, and N2 separately or simultaneously, leading to interesting findings.
The relationship between serum uric acid (SUA) and nonalcoholic fatty liver disease (NAFLD) has been previously reported. Controlled attenuation parameter (CAP) has better diagnostic performance than ...ultrasonography for assessing hepatic steatosis. The association of SUA with hepatic steatosis detected by CAP is worth further study.
The US population aged 20 years or older from the National Health and Nutrition Examination Survey (NHANES) was assessed. Hepatic steatosis was evaluated by the controlled attenuation parameter (CAP). NAFLD status was defined as CAP values of 268 dB/m without hepatitis B or C virus infection or considerable alcohol consumption. Multiple imputations were performed to fill in the missing covariate values. Linear regression, logistic regression, and smooth curve fitting were used to examine the association.
In total, 3919 individuals participated in this study. There was a positive association between SUA (µmol/L) and CAP (β = 0.14, 95% CI: 0.12-0.17, P < 0.01). After stratification by sex, a significant relationship between SUA and CAP existed in both males (β = 0.12, 95% CI: 0.09-0.16, P < 0.01) and females (β = 0.17, 95% CI: 0.14-0.20, P < 0.01) after multiple imputation. The inflection points of the threshold effect of SUA on CAP were 487.7 µmol/L in males and 386.6 µmol/L in females. There was a positive association between SUA (mg/dL) and NAFLD (OR = 1.30, 95% CI: 1.23-1.37, P < 0.01). After stratification by race, positive relationships were also observed. Meanwhile, a positive relationship existed between hyperuricemia and NAFLD (OR = 1.94, 95% CI: 1.64-2.30, P < 0.01). The positive relationship was more significant in females than in males (P for interaction < 0.01).
There was a positive association between SUA and CAP, as well as between SUA and NAFLD. Subgroup studies stratified by sex and ethnicity demonstrated that the effects were consistent.
AKI in the hospital is common and is associated with excess mortality. We examined whether AKI is also independently associated with a higher risk of different cardiovascular events in the first year ...after discharge.
We conducted a retrospective analysis of a cohort between 2006 and 2013 with follow-up through 2014, within Kaiser Permanente Northern California. We identified all adults admitted to 21 hospitals who had one or more in-hospital serum creatinine test result and survived to discharge. Occurrence of AKI was on the basis of Kidney Disease: Improving Global Outcomes diagnostic criteria. Potential confounders were identified from comprehensive inpatient and outpatient, laboratory, and pharmacy electronic medical records. During the 365 days after discharge, we ascertained occurrence of heart failure, acute coronary syndromes, peripheral artery disease, and ischemic stroke events from electronic medical records.
Among a matched cohort of 146,941 hospitalized adults, 31,245 experienced AKI. At 365 days postdischarge, AKI was independently associated with higher rates of the composite outcome of hospitalization for heart failure and atherosclerotic events (adjusted hazard ratio aHR, 1.18; 95% confidence interval 95% CI, 1.13 to 1.25) even after adjustment for demographics, comorbidities, preadmission eGFR and proteinuria, heart failure and sepsis complicating the hospitalization, intensive care unit (ICU) admission, length of stay, and predicted in-hospital mortality. This was driven by an excess risk of subsequent heart failure (aHR, 1.44; 95% CI, 1.33 to 1.56), whereas there was no significant association with follow-up atherosclerotic events (aHR, 1.05; 95% CI, 0.98 to 1.12).
AKI is independently associated with a higher risk of cardiovascular events, especially heart failure, after hospital discharge.
Peritoneal dialysis (PD) remains greatly underutilized in the United States despite the widespread preference of home modalities among nephrologists and patients. A hemodialysis-centric model of ...end-stage renal disease care has perpetuated for decades due to a complex set of factors, including late end-stage renal disease referrals and patients who present to the hospital requiring urgent renal replacement therapy. In such situations, PD rarely is a consideration and patients are dialyzed through a central venous catheter, a practice associated with high infection and mortality rates. Recently, the term urgent-start PD has gained momentum across the nephrology community and has begun to change this status quo. It allows for expedited placement of a PD catheter and initiation of PD therapy within days. Several published case reports, abstracts, and poster presentations at national meetings have documented the initial success of urgent-start PD programs. From a wide experiential base, we discuss the multifaceted issues related to urgent-start PD implementation, methods to overcome barriers to therapy, and the potential impact of this technique to change the existing dialysis paradigm.
Fluoride pollution in water has been reported in many regions and countries. Adsorption is the most commonly used process for treating fluoride-containing water. For industrial applications, the ...treatment of a pollutant is normally performed in continuous column mode. In this work, batch and lab-scale column studies were conducted by applying modified granular activated carbon (MGAC) to remove fluoride (F−) from an aqueous solution. MGAC was prepared by a wet impregnation method and characterized using SEM and FTIR. Batch studies presented the adsorption of F− onto MGAC following the Freundlich model and the pseudo-second-order model, indicating the dominant adsorption was a multilayer adsorption and chemisorption process. The breakthrough time, exhaustion time, adsorption capacity, and adsorption efficiency in breakthrough curves were evaluated under varying influent F− concentrations, flow rates, and bed heights. Thomas, Yoon-Nelson, and Yan models were employed to describe the whole breakthrough behavior, showing their suitability to predict the features of the breakthrough curves of the MGAC continuous flow system.
Acute kidney injury (AKI) has numerous sequelae. Repeated episodes of AKI may be an important determinant of adverse outcomes, including chronic kidney disease and death. In a population-based cohort ...study, we sought to determine the incidence of and predictors for recurrent AKI.
Retrospective cohort study.
38,659 hospitalized members of Kaiser Permanente Northern California who experienced an episode of AKI from 2006 to 2013.
Demographic, clinical, and laboratory data, including baseline kidney function, proteinuria, hemoglobin level, comorbid conditions, and severity of AKI.
Incidence and predictors of recurrent AKI.
Multivariable Cox proportional hazard regression.
11,048 (28.6%) experienced a second hospitalization complicated by AKI during follow-up (11.2 episodes/100 person-years), with the second episode of AKI occurring a median of 0.6 (interquartile range, 0.2-1.9) years after the first hospitalization. In multivariable analyses, older age, black race, and Hispanic ethnicity were associated with recurrent AKI, along with lower estimated glomerular filtration rate, proteinuria, and anemia. Concomitant conditions, including heart failure, acute coronary syndrome, diabetes, and chronic liver disease, were also multivariable predictors of recurrent AKI. Those who had higher acuity of illness during the initial hospitalization were more likely to have recurrent AKI, but greater AKI severity of the index episode was not independently associated with increased risk for recurrent AKI. In multivariable analysis of matched patients, recurrent AKI was associated with an increased rate of death (HR, 1.66; 95% CI, 1.57-1.77).
Analyses were based on clinically available data, rather than protocol-driven timed measurements of kidney function.
Recurrent AKI is a common occurrence after a hospitalization complicated by AKI. Based on routinely available patient characteristics, our findings could facilitate identification of the subgroup of patients with AKI who may benefit from more intensive follow-up to potentially avoid recurrent AKI episodes.
The Kidney Failure Risk Equation (KFRE) and Kaiser Permanente Northwest (KPNW) models have been proposed to predict progression to ESKD among adults with CKD within 2 and 5 years. We evaluated the ...utility of these equations to predict the 1-year risk of ESKD in a contemporary, ethnically diverse CKD population. We conducted a retrospective cohort study of adult members of Kaiser Permanente Northern California (KPNC) with CKD Stages 3-5 from January 2008-September 2015. We ascertained the onset of ESKD through September 2016, and calculated stage-specific estimates of model discrimination and calibration for the KFRE and KPNW equations. We identified 108,091 eligible adults with CKD (98,757 CKD Stage 3; 8,384 CKD Stage 4; and 950 CKD Stage 5 not yet receiving kidney replacement therapy), with mean age of 75 years, 55% women, and 37% being non-white. The overall 1-year risk of ESKD was 0.8% (95%CI: 0.8-0.9%). The KFRE displayed only moderate discrimination for CKD 3 and 5 (c = 0.76) but excellent discrimination for CKD 4 (c = 0.86), with good calibration for CKD 3-4 patients but suboptimal calibration for CKD 5. Calibration by CKD stage was similar to KFRE for the KPNW equation but displayed worse calibration across CKD stages for 1-year ESKD prediction. In a large, ethnically diverse, community-based CKD 3-5 population, both the KFRE and KPNW equation were suboptimal in accurately predicting the 1-year risk of ESKD within CKD stage 3 and 5, but more accurate for stage 4. Our findings suggest these equations can be used in1-year prediction for CKD 4 patients, but also highlight the need for more personalized, stage-specific equations that predicted various short- and long-term adverse outcomes to better inform overall decision-making.
Little population-based data exist about adults with primary nephrotic syndrome.
To evaluate kidney, cardiovascular, and mortality outcomes in adults with primary nephrotic syndrome, we identified ...adults within an integrated health care delivery system (Kaiser Permanente Northern California) with nephrotic-range proteinuria or diagnosed nephrotic syndrome between 1996 and 2012. Nephrologists reviewed medical records for clinical presentation, laboratory findings, and biopsy results to confirm primary nephrotic syndrome and assigned etiology. We identified a 1:100 time-matched cohort of adults without diabetes, diagnosed nephrotic syndrome, or proteinuria as controls to compare rates of ESKD, cardiovascular outcomes, and death through 2014, using multivariable Cox regression.
We confirmed 907 patients with primary nephrotic syndrome (655 definite and 252 presumed patients with FSGS 40%, membranous nephropathy 40%, and minimal change disease 20%). Mean age was 49 years; 43% were women. Adults with primary nephrotic syndrome had higher adjusted rates of ESKD (adjusted hazard ratio aHR, 19.63; 95% confidence interval 95% CI, 12.76 to 30.20), acute coronary syndrome (aHR, 2.58; 95% CI, 1.89 to 3.52), heart failure (aHR, 3.01; 95% CI, 2.16 to 4.19), ischemic stroke (aHR, 1.80; 95% CI, 1.06 to 3.05), venous thromboembolism (aHR, 2.56; 95% CI, 1.35 to 4.85), and death (aHR, 1.34; 95% CI, 1.09 to 1.64) versus controls. Excess ESKD risk was significantly higher for FSGS and membranous nephropathy than for presumed minimal change disease. The three etiologies of primary nephrotic syndrome did not differ significantly in terms of cardiovascular outcomes and death.
Adults with primary nephrotic syndrome experience higher adjusted rates of ESKD, cardiovascular outcomes, and death, with significant variation by underlying etiology in the risk for developing ESKD.
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