Spot Urine Samples Research Articles

MyACR: A Point-of-Care Medical Device for Determination of Albumin-Creatinine Ratio (uACR) in Random Urine Samples as a Marker of Nephropathy.

Chronic kidney disease (CKD) is a progressive condition that affects more than 10% of the world's population. Monitoring urine albumin-to-creatinine ratio (uACR) has become the gold standard for nephropathy diagnosis and control. The objective of the present study was to develop a simple, accurate, sensitive, and rapid point-of-care test (PoCT) device, MyACR, for uACR measurement, intended for use in community healthcare to screen for the risk and monitor the progress of CKD. Albumin and creatinine concentrations in urine samples were determined using spectrophotometric dye (tetrabromophenol blue)-binding and colorimetric Jaffe assay, respectively. Urine samples were diluted with distilled water (1:80) and mixed separately with albumin and creatinine reaction mixture. The creatinine reaction was incubated at room temperature (25 °C) for 30 min before analysis. Optical density (OD) was measured at the wavelengths of 625 nm (albumin) and 515 nm (creatinine). All calibration curves (0-60 mg/L and 0-2 mg/dL for albumin and creatinine) yielded linear relationships with correlation coefficients (R2) of >0.997. Good accuracy (% deviation of mean value (DMV) ≤ 5.42%) and precision (% coefficients of variation (CV) ≤ 12.69%) were observed from both the intra- and inter-day assays for the determination of albumin and creatinine using MyACR. The limit of quantification (LOQ) of albumin and creatinine in urine samples determined using MyACR and a laboratory spectrophotometer were 5 mg/L and 0.25 mg/dL, respectively, using 37.5 μL urine spiked samples (n = 5). The device was well-applied with clinical samples from 20 CKD patients. The median (range) of %DMV of the central (hospital) laboratory method (immune-based assay) was 3.48 (-17.05 to 21.64)%, with a high correlation coefficient (R2 > 0.98). In conclusion, MyACR showed satisfactory test performance in terms of accuracy, reproducibility, and sensitivity. Cost-effectiveness and improvement in clinical decision making need to be proven in future multisite community and home studies.

Longevity of Schistosoma mansoni circulating cathodic antigens in filter paper dried urine spots

ObjectivesThis study aims to determine the temporal stability of Schistosoma mansoni circulating cathodic antigens (CCA) in filter paper-based dried urine spot (FP-DUS) samples under varying temperatures condition. MethodsUrine from 20 children confirmed to have S. mansoni infection using Kato-Katz (at least 1 egg per gram of stool) and Schisto POC-CCA (2+ and 3+) methods were stored in form of FP-DUS and urine at room temperature (RT), 4 °C and −20 °C. Standard urine and FP-DUS Schisto POC-CCA methods were employed to detect CCA in urine and FP-DUS samples respectively, at weeks 4, 8 and 12. The results were reported as negative or positive (trace, 1+. 2+, and 3+). ResultsIn FP-DUS samples, POC-CCA scores initially increase after 4–8 weeks, but then showed a decrease in intensity while still remaining positive, independent of temperature condition. From week 4 to week 12, at least 80 % of urine samples had POC-CCA score of 3+, independent of temperature condition. However, 2 urine samples at RT tested negative at weeks 8 and 12. ConclusionsDespite the decrease in the intensity of test line in many samples, S. mansoni CCA remains stable and detectable in urine samples stored in FP-DUS.

Urinary polycyclic aromatic hydrocarbon metabolites in Chinese pregnant women: Concentrations, variability, predictors, and association with oxidative stress biomarkers

Polycyclic aromatic hydrocarbons (PAHs) are a class of pervasive contaminants having adverse health effects. Urinary monohydroxylated PAHs (OH-PAHs) are commonly employed as biomarkers to estimate PAH exposure levels in humans. However, little is understood about the variability in OH-PAHs among pregnant women across trimesters and their relationship with oxidative stress biomarkers (OSBs). Based on a prospective birth cohort study conducted in Wuhan, China, we selected 644 women who donated (spot) urine samples across different trimesters and measured the urinary concentrations of eight OH-PAHs and three selected OSBs (8-OHG, 8-OHdG, and HNEMA) to explore the relationship between the OH-PAHs and OSBs. Pregnant women were found to be ubiquitously exposed to the PAHs, with detection rates of the OH-PAHs ranging from 86.3% to 100%. 2-Hydroxynaphthalene (2-OH-Nap) had the highest urinary concentrations among the OH-PAHs during the three trimesters (specific gravity-adjusted median values for the first, second, and third trimesters: 1.86, 2.39, and 2.20 ng/mL, respectively). However, low reproducibility of the OH-PAHs was observed across the three trimesters with intraclass correlation coefficients ranged between 0.02 and 0.22. Most urinary OH-PAHs had the highest concentrations at the first trimester and the lowest at the third trimester. Some OH-PAH concentrations were higher in pregnant women with lower educational level [2-hydroxyphenanthrene (2-OH-Phen) and 3-hydroxyphenanthrene (3-OH-Phen)], those who were overweight [2-OH-Nap, 2/3-hydroxyfluorene (2/3-OH-Fluo), 2-OH-Phen, and 4-hydroxyphenanthrene (4-OH-Phen)], those who were unemployed during pregnancy [1-hydroxynaphthalene, 1/9-hydroxyphenanthrene, and 4-OH-Phen], and the samples donated in summer (most OH-PAHs, except for 2-OH-Nap). In multivariable linear mixed-effects model analyses, every OH-PAH was found to be significantly associated with increased levels of the three OSBs. For example, each interquartile range-fold increase in 2/3-OH-Fluo concentration was associated with the largest increase in 8-OHdG (65.4%) and 8-OHG (49.1%), while each interquartile range-fold increase in 3-OH-Phen concentration was associated with the largest increase in HNEMA (76.3%). Weighted quantile sum regression models, which were used to examine the joint effect of OH-PAH mixture on the OSBs, revealed positive associations between the OH-PAH mixture exposure and the OSBs. Specifically, 2/3-OH-Fluo and 2-OH-Nap were the major contributors in the association with oxidative damage of nucleic acids (8-OHdG and 8-OHG), while hydroxyphenanthrenes and 1-hydroxypyrene were the major contributors in the association with oxidative damage of lipid (HNEMA). Further work is required to examine the potential mediating role of oxidative stress in the relationship of adverse health outcomes with elevated PAH exposure among pregnant women.

Dietary intake of luteolin is negatively associated with all-cause and cardiovascular mortality in chronic kidney disease patients

BackgroundLuteolin (Lut), a flavonoid present in the daily diet, exhibits potent anti-inflammatory and renoprotective effects. However, the association between Lut and chronic kidney disease (CKD) remains uncertain. The objective of this study is to explore the potential correlation.MethodsA total of 2,393 CKD patients were enrolled in a prospective cohort in the National Health and Nutrition Examination Survey (NHANES). A 24-h dietary recall was utilized to estimate the intake of dietary Lut based on the type and amount of food consumed. The National Death Index mortality data was utilized to ascertain all-cause and cardiac mortality (as of December 27, 2023). Cox proportional hazards model was used to estimate the relationship between Lut intake and mortality risk.ResultsThe median Lut intake was 0.305 mg/day, with interquartile range was 0.105–0.775 mg/day. During the follow-up period (median, 93 months), 682 all-cause deaths (217 cardiovascular disease [CVD] deaths) were recorded. Per unit increase in Lut intake reduced all-cause mortality by 27% (P < 0.001) and cardiac mortality by 34% (P = 0.01) in CKD patients. There was an inverse dose–response association between Lut intake (range: 0–8.945 mg/day) and mortality risk. Consistent results were also shown when stratified by age, sex, race, marital status, body mass index, CKD stage, urine protein creatinine ratio strata, CKD progression risk, hypertension, and CVD.ConclusionDietary Lut intake is associated with a reduction in all-cause and cardiac mortality among CKD patients, potentially attributable to the anti-inflammatory characteristics of Lut.

Associations between urine specific gravity and race/ethnicity at the population level: Implications for hydration status categorization.

We aimed to evaluate how urine specific gravity (USG) and rates of supposed hypohydration vary by race/ethnicity, and to examine how adjustment for several important factors impacts estimated USG. Using the National Health and Nutrition Examination Survey, this cross-sectional study evaluated a total of 4195 (2098 female, 2097 male) Americans and categorized them as supposedly hypohydrated (USG≥1.020) or not using spot urine samples. USG and prevalence of supposed hypohydration were compared across racial/ethnic groups, separately by gender. The analyses considered the impact of urine creatinine, body composition, age, dietary nutrients, and physical activity. Differences in supposed hypohydration prevalence were observed by race/ethnicity in men (p = .030) and women (p < .001). In unadjusted models, Black women's USG (1.0189) was higher (p < .05) than all the other race/ethnicity groups' USG (1.0142-1.0171). In men, Blacks' USG (1.0197) was higher (p < .05) than the USG of Whites (1.0177) and other/multi-racial (1.0176) but not Mexican Americans (1.0196) or other Hispanics (1.0192). Adjustments for age, arm circumference, nutrients (protein, sodium, potassium, and moisture), and physical activity minimally influenced USG estimates. Further adjustment for urine creatinine lowered USG for Black women and men by 0.003 and 0.0023, respectively, with no notable lowering of USG in the other races/ethnicities. Supplemental analyses matching Whites and Blacks on age, moisture intake, and poverty-to-income ratio confirmed racial differences in urine creatinine and USG, though the effects were most pronounced in women. Using a USG≥1.020 to identify hypohydration in all races/ethnicities may be inappropriate due to, among other factors, differences in urinary creatinine.

Exploring associations between the Phthalate Environmental Reproductive Health Literacy (PERHL) scale & biomarkers of phthalate exposure: A pilot study.

Perinatal exposure to phthalates is associated with adverse health impacts for parents and children. The field of environmental health literacy seeks to measure how environmental health information is conceptualized and used to inform behaviors. We assessed whether scores on the validated Phthalate Environmental Reproductive Health Literacy (PERHL) scale were associated with biomarkers of phthalate exposure. 42 members of the Environmental Reproductive and Glucose Outcomes (ERGO) cohort completed the PERHL scale and provided spot urine samples. Phthalate summary measures for model outcomes were created by calculating molar sums of specific gravity-corrected metabolite concentrations representing exposure to parent phthalate, Di(2-ethylhexyl)phthalate (DEHP), personal care product (PCP)-associated phthalates, and parent butyl-phthalates. Linear regression models were used to estimate the associations of the PERHL scale scores with phthalate summary measures, controlling for educational attainment (college degree or higher vs. no college degree), age (years), and race and ethnicity (non-Hispanic White vs. non-White). Higher scores on the PERHL Scale and subscales were generally associated with lower ΣDEHP, Σbutyl, and ΣPCP metabolite concentrations. A one-point increase in the 'Protective Behavior/Risk Control' subscale score was significantly associated with a -30.3% (95% CI: -50.1, -2.6) decrease in ΣDEHP, and a -30.6% (95% CI: -51.5, -0.63) decrease in Σbutyl metabolite concentrations.

Associations between urinary level of bisphenol A, phthalates, 8-iso-prostaglandin-F2α, and emotional and behavioral problems among Chinese adolescents

BackgroundEmotional and behavioral problems (EBPs) of adolescents is a worldwide public health problem. Bisphenol A (BPA) and phthalate (PAEs) are prevalent and potentially toxic to human health. Therefore, this study aimed to investigate the associations between urinary level of BPA, PAEs, 8-iso-prostaglandin-F2α (8-iso-PGF2α), and EBPs. MethodsA total of 865 Chinese adolescents were included in this study and EBPs was assessed using the Strengths and Difficulties Questionnaire (SDQ). Urinary concentrations of BPA and seven PAEs metabolites in adolescents were determined by high performance liquid chromatography-tandem mass spectrometry. Urinary 8-iso-PGF2α concentration was detected by enzyme-linked immunosorbent assay (ELISA). Spearman rank correlation analysis, multivariate logistic regression analysis, restricted cubic spline functions were used to explore the relationship between the levels of BPA, PAEs, 8-iso-PGF2α and EBPs. ResultsBPA and PAEs metabolites were positively associated with EBPs in Chinese adolescents. And the 8-iso-PGF2α was significantly non-linearly correlated with emotional symptoms, conduct problems, peer problems and total difficulties. Furthermore, 8-iso-PGF2α may partially mediate the association between BPA and PAEs exposure and EBPs. LimitationsThis study was a cross-sectional study, the cause-effect relationship between BPA, PAEs exposure and EBPs could not be determined. A single spot urine sample for BPA and PAEs exposure characterization maybe could not represent their long-term exposure level. ConclusionsHigh exposure of BPA and PAEs are associated with EBPs, which may be partly mediated by oxidative stress among adolescents. The results of this study could provide certain ideas for subsequent related research.

The association between urinary sodium and the risk of dementia: Evidence from a population-based cohort study

BackgroundSodium intake reduction is crucial for cardiovascular health, however, its lasting impact on dementia remains unclear. MethodsWe included 458,577 UK Biobank participants without dementia at baseline. We estimated 24-h urinary sodium (E24hUNa) using spot urinary parameters and obtained the incidence of all-cause dementia, Alzheimer's disease, and vascular dementia from multiple sources. ResultsThe mean E24hUNa was 3.0 g (1st-99th percentile: 1.5 g–5.1 g). Over a mean follow-up of 13.6 years, 7886 (1.7 %) participants developed all-cause dementia, including 3763 (0.8 %) Alzheimer's disease and 1851 (0.4 %) vascular dementia. In the restricted cubic spline model, we identify a potential cutoff of 3.13 g for E24hUNa, below which each 1 g decrease in E24hUNa was associated with 21 % (95 % confidence interval [CI] 1.11–1.34) higher all-cause dementia risk and 35 % (95 % CI 1.11–1.63) higher vascular dementia risk (P-value <0.001 for non-linearity). The hazard ratios were 1.15 (95 % CI, 1.07–1.24) for all-cause dementia and 1.21 (95 % CI 1.04–1.40) for vascular dementia among individuals with E24hUNa below 3.13 g compared to those with E24hUNa higher than 3.13 g. LimitationsOne of the major limitations is the estimation of 24-h urinary sodium with spot urine samples. ConclusionsAn E24hUNa level below 3.13 g, equivalent to 3.37 g daily sodium intake, is associated with increased risks of all-cause and vascular dementia. This exploratory study suggests a potential lower limit below which the risk of dementia increases with a lower sodium level. Future studies are necessary to validate our findings.

Urinary concentrations of mineral elements and their predictors in pregnant women in Jinan, China

BackgroundThe essential mineral elements play important roles in proper growth, development and maintenance of physiological homeostasis of an organism. Women are at greater risk of mineral deficiency during pregnancy. However, the predictors of mineral element levels in pregnant women remain unclear. This study was conducted to determine the urinary levels of calcium (Ca), iron (Fe), copper (Cu), manganese (Mn) and selenium (Se) in women during early pregnancy and to explore the predictors of urinary exposure to each mineral element and high co-exposure to mineral element mixture. Methods298 pregnant women in first trimester were recruited when they attended antenatal care in a hospital in Jinan, Shandong Province, China. We collected their spot urine samples and questionnaire data on their sociodemographic characteristics, lifestyle habits, food and dietary supplement intake, and residential environment. The concentrations of Ca, Fe, Cu, Mn and Se in all urine samples were measured. LASSO regression, multiple linear regression and binary logistic regression were used to analyze the predictors affecting mineral element levels. ResultsThe geometric means of creatinine-corrected Ca, Fe, Cu, Mn and Se concentrations were 99.37 mg/g, 1.75 µg/g, 8.97 µg/g, 0.16 µg/g and 16.83 µg/g creatinine, respectively. Factors that influenced the concentrations of individual mineral element were as follows: (1) Se and Ca concentrations increased with maternal age; (2) women taking tap water as family drinking water had higher Ca levels and those taking polyunsaturated fatty acids intermittently had higher Cu levels; (3) Fe was adversely related to consumption frequency of barbecued foods; (4) Pregnant women with more frequent consumption of shellfish/shrimp/crab and living near green spaces or parks had higher Mn exposure, and those with higher frequency of meat consumption had lower Mn exposure. In addition, maternal age and the frequency of egg consumption were associated with odds of exposure to a mixture of high Ca, Fe, Cu and Se. ConclusionsThe pregnant women in this study had comparable concentrations of urinary Cu and Se but lower concentrations of Ca, Fe and Mn compared with those in other areas. Predictors of urinary mineral elements included maternal age (Se and Ca), type of domestic drinking water (Ca), consumption frequency of barbecued food (Fe), polyunsaturated fatty acid use (Cu), the presence of urban green spaces or parks near the home and frequency of meat and shellfish/shrimp/crab intake (Mn). Moreover, maternal age and egg consumption frequency were significant predictors of high-level co-exposure to urinary Ca, Fe, Cu and Se.

Organophosphate ester flame retardant chemicals and maternal depression during pregnancy

BackgroundDepression substantially contributes to pregnancy-related morbidity, and pregnancy is increasingly recognized as a vulnerable window for exposure effects on maternal mental health. Exposures to organophosphate esters (OPEs) are ubiquitous and may have neurotoxic effects; however, their impacts on prenatal depression remain unknown. We evaluated associations of third trimester OPE metabolites on maternal depressive symptoms during pregnancy. MethodsThis study included 422 participants in the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) cohort, a prospective pregnancy cohort of primarily low-income and Hispanic participants residing in Los Angeles, California. We measured concentrations of nine OPEs in third trimester spot urine samples (mean gestational age = 31.5 ± 2.0 weeks). Using the Center for Epidemiologic Studies-Depression (CES-D) scale, we classified participants as having probable depression during pregnancy (N = 137) or not (N = 285) if one or more CES-D scores administered at each trimester met the suggested cutoff score for clinically significant depressive symptoms (≥16). We estimated associations of prenatal OPE metabolite concentrations in tertiles and risk of prenatal depression using modified Log-Poisson regression. We examined associations of the OPE mixture on depression during pregnancy using Bayesian kernel machine regression (BKMR). ResultsParticipants with the highest tertiles of DPHP and BDCIPP exposure had a 67% (95% CI: 22%, 128%) and 47% (95% CI: 4%, 108%) increased risk of maternal depressive symptoms during pregnancy, respectively. No associations between other OPE metabolites and maternal depression symptoms were observed. In mixture analyses, we observed a positive and linear association between higher exposure to the OPE metabolite mixture and odds of prenatal maternal depression, primarily driven by DPHP. ConclusionsOur findings provide new evidence of associations between frequently detected OPE metabolites on maternal depression symptoms during pregnancy. Results could inform future intervention efforts aimed at reducing perinatal maternal depression.

Clinical outcomes in patients switching from agalsidase beta to migalastat: A Fabry Registry analysis.

Fabry Registry data were analyzed among 83 agalsidase beta-treated patients with Fabry disease who switched to migalastat. Outcomes (estimated glomerular filtration rate [eGFR], urine protein-creatinine ratio [UPCR], plasma globotriaosylceramide [GL-3], plasma globotriaosylsphingosine [lyso-GL-3], interventricular septal wall thickness [IVST], left posterior wall thickness [LPWT], left ventricular mass index [LVMI]) were assessed using linear mixed models to estimate annual change over time in the pre- and postswitch periods. eGFR decreased throughout both periods (preswitch: -0.85 mL/min/1.73 m2/year; postswitch: -1.96 mL/min/1.73 m2/year; both p < 0.0001), with steeper decline postswitch (ppre/post = 0.01) in both classic and late-onset patients. UPCR increased significantly postswitch (ppre/post = 0.003) among classic patients and was stable in both periods among late-onset patients. GL-3 trajectories worsened postswitch across phenotypes (ppre/post = 0.0005 classic, 0.02 late-onset). LPWT was stable preswitch (0.07 mm/year, p = 0.25) and decreased postswitch (-0.51 mm/year, p = 0.0005; ppre/post = 0.0009), primarily among late-onset patients. IVST and LVMI slopes varied significantly by phenotype. Among classic patients, IVST and LVMI were stable and decreasing, respectively preswitch and increasing postswitch (ppre/post = 0.02 IVST, 0.01 LVMI). Among late-onset patients, IVST significantly decreased postswitch (ppre/post = 0.0003); LVMI was stable over time (ppre/post = 0.89). Ultimately, eGFR and GL-3 trajectories worsened postswitch across phenotypes, while UPCR and cardiac measures worsened among classic and stabilized/improved among late-onset patients. These findings indicate variability in long-term outcomes after switching from ERT to migalastat, underscoring the importance of careful monitoring.

Urinary metabolomics signature of animal and plant protein intake and its association with 24-h blood pressure: the African-PREDICT study.

The contrasting relationships of plant and animal protein intake with blood pressure (BP) may be partially attributed to the differential non-protein (e.g., saturated fat and fibre) and amino acid (AA) compositions. This study determined whether animal and plant protein intake were related to differential metabolomic profiles associated with BP. This study included 1008 adults from the African-PREDICT study (aged 20-30 years). Protein intake was determined using 24-h dietary recalls. Twenty-four-hour ambulatory BP was measured. Amino acids and acylcarnitines were analysed in spot urine samples using liquid chromatography-tandem mass spectrometry-based metabolomics. Participants with a low plant, high animal protein intake had higher SBP (by 3 mmHg, p = 0.011) than those with high plant, low animal protein intake (low-risk group). We found that the relationships of plant and animal protein intake with 24-h SBP were partially mediated by BMI and saturated fat intake, which were independently associated with SBP. Protein intake was therefore not related to SBP in multiple regression analysis after adjusting for confounders. In the low-risk group, methionine (Std. β = -0.217; p = 0.034), glutamic acid (Std. β = -0.220; p = 0.031), glycine (Std. β = -0.234; p = 0.025), and proline (Std. β = -0.266; p = 0.010) were inversely related to SBP, and beta-alanine (Std. β = -0.277; p = 0.020) to DBP. Ultimately a diet high in animal and low in plant protein intake may contribute to higher BP by means of increased BMI and saturated fat intake. Conversely, higher levels of urinary AAs observed in adults consuming a plant rich diet may contribute to lower BP.

Value of urinary CD80 in differentiating minimal change disease from focal segmental glomerulosclerosis

Background. Minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) are two common forms of childhood nephrotic syndrome (NS). Separating MCD from FSGS is essential to determine the treatment therapy and the prognosis. Cluster of differentiation 80 (CD80) in urine is now considered a valuable marker for detecting MCD. Therefore, we conducted this research to evaluate the role of urinary CD80 concentrations in differentiating MCD from FSGS. Methods. A cross-sectional descriptive study was performed on 67 children with NS who underwent kidney biopsy and 67 children in the control group. Results. MCD accounted for the majority (61.2%), while FSGS accounted for 38.8% with an MCD/FSGS ratio of 1.6:1. There were no significant differences in age, gender, hematuria, hypertension, urinary protein-creatinine ratio, and albumin concentrations between the two study groups (p&gt;0.05). There were statistically significant differences in glomerular filtration rate (GFR) between the two study groups with p&lt;0.05. The urinary CD80/creatinine ratio in the MCD group was 25.6 (5.4-38.3) pg/µmol, which was significantly higher than that of the FSGS group (3.6 (1.9-6.5) pg/µmol) with p&lt;0.05. The area under the ROC curve for urinary CD80/creatinine ratio in the diagnosis of MCD with FSGS was 0.87 (95% CI 0.79-0.95) at a cut-off value of 4.6 pg/µmol, with a sensitivity of 85.4% and specificity of 73.1%, p&lt;0.05. Conclusion. The urinary CD80/creatinine ratio was useful in differentiating between nephrotic syndrome with MCD and FSGS.

Spot urinary sodium in CKD patients: correlation with 24h-excretion and evaluation of commonly used prediction equations

BackgroundSalt intake in CKD patients can affect cardiovascular risk and kidney disease progression. Twenty-four hour (24h) urine collections are often used to investigate salt metabolism but are cumbersome to perform. We assessed urinary sodium (U-Na) concentration in spot urine samples and investigated the correlation with 24h U-Na excretion and concentration in CKD patients under nephrological care. Further, we studied the role of CKD stage and diuretics and evaluated the performance of commonly used formulas for the prediction of 24h U-Na excretion from spot urine samples.MethodsOne hundred eight patients of the German Chronic Kidney Disease (GCKD) study were included. Each participant collected a 24h urine and two spot urine samples within the same period. The first spot urine sample (AM) was part of the second morning urine. The second urine sample was collected before dinner (PM). Patients were advised to take their medication as usual without changing dietary habits. U-Na concentrations in the two spot urine samples and their average ((AM + PM)/2) were correlated with U-Na concentration and total Na excretion in the 24h urine collections. Correlations were subsequently studied after stratification by CKD stage and diuretic intake. The usefulness of three commonly applied equations to estimate 24h U-Na excretion from spot urine samples (Kawasaki, Tanaka and Intersalt) was determined using Bland–Altman plots, analyses of sensitivity, specificity, as well as positive (PPV) and negative predictive values (NPV).ResultsParticipants (42 women, 66 men) were on average (± SD) 62.2 (± 11.9) years old, with a mean serum creatinine of 1.6 (± 0.5) mg/dl. 95% had arterial hypertension, 37% diabetes mellitus and 55% were on diuretics. The best correlation with 24h U-Na total excretion was found for the PM spot U-Na sample. We also found strong correlations when comparing spot and 24h urine U-Na concentration. Correction of spot U-Na for U-creatinine did not improve strength of correlations. Neither CKD stage, nor intake of diuretics had significant impact on these correlations. All examined formulas revealed a significant mean bias. The lowest mean bias and the strongest correlation between estimated and measured U-Na excretion in 24h were obtained using the Tanaka-formula. Also, application of the Tanaka-formula with PM U-Na provided best sensitivity, specificity, PPV and NPV to estimate U-Na excretion > 4g/d corresponding to a salt consumption > 10g/d.ConclusionU-Na concentration of spot urine samples correlated with 24h U-Na excretion especially when PM spot U-Na was used. However, correlation coefficients were relatively low. Neither CKD stage nor intake of diuretics appeared to have an influence on these correlations. There was a significant bias for all tested formulas with the Tanaka-formula providing the strongest correlation with measured 24h U-Na excretion. In summary, using spot urine samples together with the Tanaka-formula in epidemiological studies appears feasible to determine associations between approximate salt intake and outcomes in CKD patients. However, the usefulness of spot-urine samples to guide and monitor salt consumption in individual patients remains limited.

Home blood pressure measurement days and changes in urinary sodium-to-potassium ratio, estimated salt and potassium intakes and blood pressure: 1-year prospective study.

Current international guidelines recommend home blood pressure (BP) measurement and low sodium and high potassium intakes for the management of hypertension. We hypothesized that increased home BP measurement may result in more effective management of sodium and potassium intakes and BP. We examined associations of home BP measurement days with changes in the urinary sodium-to-potassium (Na/K) ratio, estimated salt and potassium intakes and BP. We included 209 healthy participants (mean age, 55.9 years; 56.5% women) from a prospective cohort study. We examined 1-year data on self-measured home BP and spot urine samples. Median (interquartile range) days of home BP measurement was 324 (225-358) over 1-year. Baseline mean (SD) Na/K ratio, salt and potassium intakes, morning and evening SBP, and morning and evening DBP were 3.8 (2.3), 8.5 (1.9) g/day, 1833.5 (416.5) mg/day, 120.4 (14.0) mmHg, 118.2 (14.2) mmHg, 79.2 (10.1) mmHg, and 76.2 (10.1) mmHg, respectively. In multivariable-adjusted linear regression , β (standard error) per 10 days increase in number of home BP measurement were -0.031 (0.017) for Na/K ratio, -0.036 (0.015) for salt intake, -1.357 (2.797) for potassium intake, -0.178 (0.064) for morning SBP, -0.079 (0.041) for morning DBP, -0.109 (0.067) for evening SBP and -0.099 (0.045) for evening DBP. Additionally, relationships persisted for men and women, but changes in salt intake were more pronounced among participants taking antihypertensive medication (interaction P = 0.002). Continuous measurement of home BP may lead not only to self-monitoring of BP, but also to declines in salt intakes and some BP indices.

Sodium and potassium excretion and its association with cardiovascular disorders in Mexican adults.

Worldwide, as well as in Mexico, the leading cause of death is cardiovascular disease (CVD). Hypertension is the main risk factor for CVD; about 50% of the adult population suffers from this condition. High sodium (Na) intake combined with low potassium (K) intake can trigger cardiovascular disorders such as high blood pressure (BP). The aim of this study was to estimate the mean excretion of Na and K in Mexican adults using a spot urine sample, and its association with cardiovascular disorders. Information on 2,778 adults, 20-59 years of age, who participated in ENSANUT-2016 was analyzed. Na and K were estimated using Tanaka formulae. Biomarkers such as glucose, total cholesterol, triglycerides, HDL cholesterol and LDL cholesterol, and anthropometry were measured. Mean Na was 3,354 mg/day (95%CI: 3,278, 3,429), 1,440 mg/day of K (95%CI: 1,412, 1,469), and the Na-K ratio was 2.4. The excretion of Na was greater in adults with high BP (3,542 mg/day) compared to those with normal BP (3,296 mg/day). In adults with hypertension, excretion of K was 10% greater (1,534 mg/day) than in adults with normal BP (1,357 mg/day). In adults with moderate reduction of renal function, Na excretion was 22% less (2,772 mg/day) than in adults with normal kidney function (3,382 mg/day). The results of this study show that the cardiovascular health of Mexican adults is at risk, as they showed high Na excretion and low K excretion.

Associations between urinary hydroxylated polycyclic aromatic hydrocarbon biomarker concentrations and measures of timing of delivery and infant size at birth

Preterm birth is a leading cause of neonatal mortality and presents significant public health concerns. Environmental chemical exposures during pregnancy may be partially to blame for disrupted delivery timing. Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion, exposure to which occurs via inhalation of cigarette smoke and automobile exhaust, and ingestion of charred meats. Exposure to PAHs in the US population is widespread, and pregnant women represent a susceptible population to adverse effects of PAHs. We aimed to investigate associations between gestational exposure to PAHs and birth outcomes, including timing of delivery and infant birth size. We utilized data from the PROTECT birth cohort where pregnant women provided spot urine samples at up to three study visits (median 16, 20, and 24 weeks gestation). Urine samples were assayed for eight hydroxylated PAH concentrations. Associations between PAHs and birth outcomes were calculated using linear/logistic regression models, with adjustment for maternal age, education, pre-pregnancy BMI, and daily exposure to environmental tobacco smoke. Models accounted for urine dilution using specific gravity. We also explored effect modification by infant sex. Interquartile range (IQR) increases in all averaged PAH exposures during the second trimester were associated with reduced gestational age at delivery and increased odds of overall PTB, although these associations were not statistically significant (p > 0.05). Most PAHs at the second study visit were most strongly associated with earlier delivery and increased odds of overall and spontaneous PTB, with visit 2 2-hydroxynapthalene (2-NAP) being significantly associated with increased odds of overall PTB (OR:1.55; 95 %CI: 1.05,2.29). Some PAHs resulted in earlier timing of delivery among only female fetuses, specifically 2-NAP on overall PTB (female OR:1.52 95 %CI: 1.02,2.27; male OR:0.78, 95 %CI: 0.53,1.15). Future work should more deeply investigate differential physiological impacts of PAH exposure between pregnancies with male and female fetuses, and on varying developmental processes occurring at different points through pregnancy.

Prospective study of the effect of rituximab on kidney function in membranous nephropathy.

Patients with membranous nephropathy (MN) and poor kidney function or active disease despite previous immunosuppression are underrepresented in clinical trials. It is unknown how effective rituximab is in this population. This prospective, multi-centre, single-arm, real-world study of patients with active MN [urine protein-creatinine ratio (uPCR) >350mg/mmol and serum albumin <30g/L, or a fall in estimated glomerular filtration rate (eGFR) of at least 20% or more over at least 3months] evaluated rituximab in those with contraindications to calcineurin inhibitors and cytotoxic therapy. The primary outcome was change in rate of eGFR decline before and after rituximab. Complete or partial remission were defined as uPCR <30mg/mmol or uPCR <350mg/mmol with a ≥50% fall from baseline, respectively. A total of 180 patients [median age 59years, interquartile range (IQR) 48-68] received rituximab and were followed up for a median duration of 17months. Seventy-seven percent had prior immunosuppression. Median eGFR and uPCR at baseline were 49.2mL/min/1.73m2 (IQR 34.4-80.6) and 766mg/mmol (IQR 487-1057), respectively. The annual rate of decline of eGFR fell from 13.9 to 1.7mL/min/1.73m2/year following rituximab (Z score=2.48, P<.0066). At 18months 12% and 42% of patients were in complete or partial remission, respectively. Rituximab was well tolerated; patient survival was 95.6% at 2years and in patients in whom eGFR was available, kidney survival was 93% at 2years. Rituximab significantly reduced the rate of eGFR decline in active MN including those who had received prior immunosuppression or with poor baseline kidney function.

Recent use of consumer and personal care products and exposures to select endocrine disrupting chemicals among urban children with asthma.

Emerging studies suggest that endocrine disrupting chemicals (EDCs) in personal care and other consumer products are linked with various adverse health effects, including respiratory and reproductive effects. Despite Black persons using more personal care products than other demographic groups and having a high asthma burden, little is known regarding their consumer product use patterns and associated EDC exposures. To examine the association between recent exposure to select EDCs with specific consumer products and behaviors in a cohort of 110 predominantly Black children with asthma, ages 8-17 years, living in Baltimore City, Maryland. We quantified concentrations of bisphenol A (BPA), bisphenol S (BPS), bisphenol F, two dichlorophenols, four parabens, triclosan, benzophenone-3, and triclocarban in spot urine samples. Questionnaires were used to capture recent (last 24-h) consumer product use and behaviors. Associations between EDCs and consumer product uses/behaviors were assessed using multivariable linear regression, adjusting for age, gender, race/ethnicity, and caregiver income level. Effect estimates were expressed as geometric mean ratios of biomarker concentrations of product-users vs non-users. Increased concentrations to select EDCs were associated with recent use of air freshener (ratios; BPA: 1.9, 95%CI 1.4-2; BPS 1.7, 95%CI 1-2.97; propyl paraben: 3.0, 95%CI 1.6-5.6), scented candles (methyl paraben: 2.6, 95%CI 1.1-6.1), and scented carpet powder (2,5-dichlorophenol: 2.8, 95%CI 1.2-6.3). Additionally, consuming canned food was associated with some increased biomarker concentrations (ratios: BPA: 1.7, 95%CI 1.2-2.4; BPS: 2.1, 95% CI: 1.2-3.6). These findings add to the body of evidence suggesting that recent use of select consumer products in Black children contributes to exposure of chemicals of concern and could potentially inform exposure mitigation interventions. Findings have broad potential health implications for pediatric populations and Black children who may face exposure and health disparities. Little is known about how children's personal care product use and consumer behaviors affect their exposures to endocrine disrupting chemicals (EDCs). This is particularly true for Black children who often experience a disparate exposure burden to many EDCs. This is a significant knowledge gap among children that are uniquely vulnerable to EDCs as they undergo critical windows of growth and development. Our findings show associations between consumer products and EDC exposures in predominantly Black children in low-income settings. Identifying EDC exposure determinants has broad health implications as many of these chemicals have been associated with adverse health risks.

Is the urinary neutrophil gelatinase-associated lipocalin concentration in children and adolescents with type 1 diabetes mellitus different from that in healthy children?

Diabetic kidney disease (DKD) is one of the major microvascular complications of type 1 diabetes mellitus (T1DM). Some studies suggest that changes of renal tubular components emerge before the glomerular lesions thus introducing the concept of diabetic tubulopathy with urinary neutrophil gelatinase-associated lipocalin (uNGAL) as a potential marker of DKD. This concept was not confirmed in all studies. In 198 T1DM patients with median age 15 years and diabetes duration over one year, an albumin/creatinine ratio (ACR) was determined and uNGAL measured in spot urine sample. Urine samples for ACR and uNGAL were also collected in the control group of 100 healthy children of similar age. There was no significant difference in uNGAL concentration or uNGAL/creatinine between T1DM children and healthy subjects (6.9 (2.8-20.1) ng/mL vs 7.9 (2.9-21.0) ng/mL, P = 0.969 and 6.8 (2.2-18.4) ng/mg vs 6.5 (1.9-13.4) ng/mg, P = 0.448, respectively) or between T1DM subjects with albuminuria A2 and albuminuria A1 (P = 0.573 and 0.595, respectively). Among T1DM patients 168 (85%) had normal uNGAL concentrations, while in 30 (15%) patients uNGAL was above the defined cut-off value of 30.9 ng/mL. There was no difference in BMI, HbA1c and diabetes duration between patients with elevated uNGAL compared to those with normal uNGAL. We found no significant difference in uNGAL concentration or uNGAL/creatinine between T1DM children and healthy subjects or between albuminuria A2 and albuminuria A1 T1DM subjects. Therefore, uNGAL should not be recommended as a single marker for detecting diabetic kidney disease in children and adolescents.