Abdelazim equation: For 24-h urine protein from spot urine sample in preeclampsia

The urinary fluoride/creatinine ratio (UF/Cr) in a spot urine sample could be a useful systemic F exposure monitoring tool. No reference value for UF/Cr currently exists, therefore this study aimed to establish an upper reference value for a UF/Cr, corresponding to excessive systemic F exposure, i.e., >0.07 mg F/kg body weight (b.w.)/day, in children. Subsidiary aims were to examine the relationship between (i) total daily F intake (TDFI) and 24-h urinary F excretion (DUFE); (ii) DUFE and UF/Cr, and (iii) TDFI and UF/Cr. Simultaneously collected TDFI, DUFE, and urinary creatinine (UCr) data in children <7 years were taken from UK studies conducted from 2002 to 2014 in order to calculate UF/Cr (mg/g) for each child. For the 158 children (mean age 5.8 years) included in the data analysis, mean TDFI and DUFE were 0.049 (SD 0.033) and 0.016 (SD 0.008) mg/kg b.w./day, respectively, and the mean UF/Cr was 1.21 (SD 0.61) mg/g. Significant (p < 0.001) positive linear correlations were found between TDFI and DUFE, DUFE and UF/Cr, and TDFI and UF/Cr. The estimated upper reference value for UF/Cr was 1.69 mg/g; this was significantly (p = 0.019) higher than the UF/Cr (1.29) associated with optimal F exposure (0.05-0.07 mg/kg b.w./day). In conclusion, the strong positive correlation between TDFI and UF/Cr confirms the strong association of these 2 F exposure variables and the value of a spot urine sample for prediction of TDFI (i.e., the most important risk factor in determining fluorosis occurrence and severity) in young children. Establishing an estimation of an upper reference value of 1.69 mg/g for UF/Cr in spot urine samples could simplify and facilitate their use as a valuable tool in large epidemiological studies.

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Microalbumin measurement alone or calculation of the albumin/creatinine ratio for the screening of hypertension patients?

Nephrology Dialysis Transplantation ◽

10.1093/ndt/17.1.81 ◽

2002 ◽

Vol 17 (1) ◽

pp. 81-85 ◽

Cited By ~ 21

Author(s):

Ulla Derhaschnig ◽

Harald Kittler ◽

Christian Woisetschläger ◽

Andreas Bur ◽

Harald Herkner ◽

...

Keyword(s):

Urine Sample ◽

Diagnostic Performance ◽

Screening Method ◽

Creatinine Ratio ◽

Operating Characteristics ◽

Albumin Creatinine Ratio ◽

Hypertensive Patients ◽

Spot Urine ◽

Spot Urine Sample ◽

Receiver Operating Characteristics Curve

Abstract Background. Spot urine sampling seems to be a reliable screening method for the detection of microalbuminuria in hypertensive patients. It remains unclear whether microalbumin measurement alone or calculation of the albumin/creatinine ratio (ACR) are more reliable for the detection of microalbuminuria in non-selected hypertensive patients. Methods. Following collection of a spot, midstream urine sample, urine was collected for 24 h for the measurement of microalbumin in 264 hypertensive patients. We compared microalbumin concentration in the spot urine with microalbumin measured in the 24-h urine sample and examined the utility of the ACR in evaluating microalbuminuria in hypertensive patients. Pathologic microalbuminuria was assumed when the microalbumin concentration exceeded 30 mg/l in the 24-h urine sample. Diagnostic performance is expressed in terms of specificity, sensitivity, positive (PPV) and negative predictive value (NPV), and area under receiver operating characteristics curve (AUC). Results. A total of 47 samples (17.8%) showed pathologic microalbuminuria in the 24-h urine sample. The diagnostic performance expressed as AUC was 0.94 (95% CI 0.90–0.98) for microalbumin measurement alone and 0.94 (95% CI 0.89–0.97) for ACR. The PPV and NPV were 44.2 and 97.9% for microalbumin measurement alone. ACR revealed a PPV of 29.3% and a NPV of 96.2% for males and 42.9 and 98% for females, if a cut-off value of 2.5 mg/mmol for males and of 4.0 mg/mmol for females was used. Conclusions. The ACR did not provide any advantage compared with microalbumin measurement alone, but requires an additional determination of creatinine and the use of gender-specific cut-off values. Therefore, measurement of microalbuminuria alone in the spot urine sample is more convenient in daily clinical practice and should be used as the screening method for hypertensive patients.

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Faculty Opinions recommendation of Assessment of lithogenic risk in children based on a morning spot urine sample.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.5762958.5743057 ◽

2010 ◽

Author(s):

Julian Wan

Keyword(s):

Urine Sample ◽

Spot Urine ◽

Spot Urine Sample

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Abstract MP16: The Validity of Predictive Equations for 24-Hour Urine Sodium Excretion Among Older Adults and Those with Hypertension: The MESA and CARDIA Urinary Sodium Study

Circulation ◽

10.1161/circ.129.suppl_1.mp16 ◽

2014 ◽

Vol 129 (suppl_1) ◽

Author(s):

Norrina B Allen ◽

Lihui Zhao ◽

Catherine Loria ◽

Linda Van Horn ◽

Chia-Yih Wang ◽

...

Keyword(s):

Older Adults ◽

Black Women ◽

Urine Sample ◽

White Women ◽

Population Distribution ◽

Urinary Sodium ◽

Dietary Sodium ◽

Spot Urine ◽

Spot Urine Sample ◽

The Mean

Background: Excess dietary sodium (Na) intake is linked to adverse cardiovascular health; the population distribution of urinary sodium (UNa) values in the US is unknown. We examined the population distribution of UNa and the validity of existing equations predicting 24-h Na excretion from a single spot urine sample among older adults with and without hypertension. Methods: Demographic, anthropometric, lab, and diet data along with 24-h urine collections were obtained from 555 MESA and CARDIA participants aged 45-79y. One third provided a second 24-h urine collection. Four timed voids (morning, afternoon, evening, and overnight) and the 24-h collection were analyzed for Na, creatinine, potassium and chloride concentrations. We examined the distribution of 24-h excretion of each analyte overall and by gender-race subgroups and hypertensive (HTN) status. We then examined the mean differences (bias) and confidence intervals between measured 24-h UNa excretion and the predicted from spot urine using 4 published equations by specimen timing, race-gender subgroups, and HTN status. Results: Using preliminary data from 265 participants with completed laboratory analysis, 55% female, 61% Black, and 60% had HTN. Mean 24-h Na excretion was 4234 ± 1920 mg for white men, 2706 ± 1136 mg for white women, 3463 ± 1691 mg for Black men and 3415 ± 1635 mg for Black women and did not significantly differ by hypertensive status. Mean bias in predicting 24-h Na excretion overall ranged from -268 (95% CI: -443.5, -91.8) to 1045 (849.3, 1240.4) mg/d. (Table) Conclusion: Among this group of older adults and those with hypertension, the mean 24-h UNa excretion levels for all race-gender groups exceeded current recommendations of 2,300 mg/d, with significant variation by race and gender. All of the four published equations under or overestimated mean 24-h Na excretion when using a single, timed spot urine sample but using evening samples appeared to produce the least bias. These preliminary findings are tentative until confirmed with the full dataset.

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Comparison of calcium, magnesium, sodium, potassium, zinc, and creatinine concentration in 24-h and spot urine samples in women

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm.2009.039 ◽

2009 ◽

Vol 47 (2) ◽

Cited By ~ 19

Author(s):

Jasminka Z. Ilich ◽

Maja Blanuša ◽

Željka Crnčević Orlić ◽

Tatjana Orct ◽

Krista Kostial

Keyword(s):

Urine Sample ◽

Rank Order ◽

Essential Elements ◽

Urine Samples ◽

Emission Spectrometry ◽

Creatinine Concentration ◽

Spot Urine ◽

Flame Atomic Absorption ◽

Spot Urine Sample ◽

Calcium Magnesium

Abstract: The 24-h urine sample is considered as the most reliable material for testing many but not necessarily all constituents in urine. However, its collection is tedious for both patients and research participants. The aim of this study was to compare concentrations of essential elements calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), and zinc (Zn) in 24-h and spot urine samples.: Urine samples were collected from 143 generally healthy women, aged 30–79 years. Fasting spot urine was collected immediately after the end of the 24-h collection, therefore being of the same content as the first morning urine which ended the 24-h collection. Elements were analyzed by flame atomic absorption/emission spectrometry and expressed as mg/g and/or mmol/mol of creatinine (Cr). Spearman rank order correlations between 24-h and spot urine were carried out for each element. Ratios of elements in 24-h to spot urine samples were calculated to estimate the element-proportion of spot in the 24-h sample.: All coefficients of correlation between 24-h and spot urine of measured elements and Cr were significant (p<0.05): Zn (0.637), Mg (0.623), Ca (0.603), Na (0.452), K (0.396), and Cr (0.217). Ratios of 24-h to spot urine samples for each element (except K) were similar and close to 2, indicating uniform proportion of elements from spot urine sample in the 24-h sample. In addition, a high correlation between various pairs of elements was obtained in both 24-h and spot urine; the highest being between Na/Ca (0.435) and (0.578), respectively. This is in accordance with theoretical presumptions and previous findings regarding those relationships.: Although replacing burdensome 24-h urine collection with spot urine sampling might not provide the solution in all cases, our results show that for the elements analyzed, spot urine could be a reliable alternative.Clin Chem Lab Med 2009;47:216–21.

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Monitoring the South African population’s salt intake: spot urine v. 24 h urine

Public Health Nutrition ◽

10.1017/s1368980017002683 ◽

2017 ◽

Vol 21 (03) ◽

pp. 480-488 ◽

Cited By ~ 9

Author(s):

Bianca Swanepoel ◽

Aletta E Schutte ◽

Marike Cockeran ◽

Krisela Steyn ◽

Edelweiss Wentzel-Viljoen

Keyword(s):

South Africa ◽

South African ◽

Urine Sample ◽

Salt Intake ◽

Urine Samples ◽

The South ◽

Population Groups ◽

Spot Urine ◽

Spot Urine Sample ◽

African Context

Abstract Objective The present study set out to determine whether morning spot urine samples can be used to monitor Na (and K) intake levels in South Africa, instead of the ‘gold standard’ 24 h urine sample. Design Participants collected one 24 h and one spot urine sample for Na and K analysis, after which estimations using three different formulas (Kawasaki, Tanaka and INTERSALT) were calculated. Setting Between 2013 and 2015, urine samples were collected from different population groups in South Africa. Subjects A total of 681 spot and 24 h urine samples were collected from white (n 259), black (n 315) and Indian (n 107) subgroups, mostly women. Results The Kawasaki and the Tanaka formulas showed significantly higher (P≤0·001) estimated Na values than the measured 24 h excretion in the whole population (5677·79 and 4235·05 v. 3279·19 mg/d). The INTERSALT formula did not differ from the measured 24 h excretion for the whole population. The Kawasaki formula seemed to overestimate Na excretion in all subgroups tested and also showed the highest degree of bias (−2242 mg/d, 95 % CI−10 659, 6175) compared with the INTERSALT formula, which had the lowest bias (161 mg/d, 95 % CI−4038, 4360). Conclusions Estimations of Na excretion by the three formulas should be used with caution when reporting on Na intake levels. More research is needed to validate and develop a specific formula for the South African context with its different population groups. The WHO’s recommendation of using 24 h urine collection until more studies are carried out is still supported.

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