Urinary Reference Values Research Articles

Validation of an automated self-administered 24-hour dietary recall web application against urinary recovery biomarkers in a sample of French-speaking adults of the province of Québec, Canada.

The objective of this study was to validate an automated self-administered 24-hour dietary recall web application (R24W) against recovery biomarkers for sodium, potassium and protein intakes and to identify individual characteristics associated with misreporting in a sample of 61 men and 69 women aged 20-65 years from Québec City, Canada. Each participant completed 3 dietary recalls using the R24W, provided two 24-hour urinary samples and completed questionnaires to document psychosocial factors. Mean reported intakes were 2.2%, 2.1% and 5.0% lower than the urinary reference values, respectively, for sodium, potassium and proteins (significant difference for proteins only (p = 0.04)). Deattenuated correlations between the self-reported intake and biomarkers were significant for sodium (r= 0.48), potassium (r= 0.56) and proteins (r= 0.68). Cross-classification showed that 39.7% (sodium), 42.9% (potassium) and 42.1% (proteins) of participants were ranked into the same quartile with both methods and only 4.8% (sodium), 3.2% (potassium) and 0.8% (proteins) were ranked in opposite quartiles. Lower body esteem related to appearance was associated with sodium underreporting in women (r= 0.33, p = 0.006). No other individual factor was found to be associated with misreporting. These results suggest that the R24W has a good validity for the assessment of sodium, potassium and protein intakes in a sample of French-speaking adults. Novelty: The validity of an automated self-administered 24-hour dietary recall web application named the R24W was tested using urinary biomarkers. According to 7 criteria, the R24W was found to have a good validity to assess self-reported intakes of sodium, potassium and proteins.

Urinary Reference Values and First Insight into the Urinary Proteome of Captive Giraffes.

Simple SummaryThe aims of this study were to determine the urinary reference values and identify the most represented proteins of the urinary proteome in captive giraffes. The reference values for the urine specific gravity, total proteins, creatinine, and urine protein:creatinine ratio, reported as the median, and lower and upper limit, were 1.030 (1006–1.049), 17.58 (4.54–35.31) mg/dL, 154.62 (39.59–357.95) mg/dL, and 0.11 (0.07–0.16), respectively. Giraffes presented a low quantity of urinary proteins, which is in accordance with the data regarding domestic ruminants. In addition to albumin, the most represented urinary proteins were lysozyme and ubiquitin, which are involved in defense mechanisms against microbes.Urinalysis is widely recognized to be a useful tool in routine health investigations, since it can diagnose numerous pathologies. Considering the paucity of knowledge concerning giraffes, urine from 44 giraffes (Giraffa camelopardalis) (18 males and 26 females, from 3 months of age to 21 years of age) underwent routine urinalysis, 1D-electrophoresis, and protein identification using mass spectrometry, with the aim of identifying the urinary reference values and the urine proteome. The urine specific gravity (USG), urine total proteins (uTP), urine creatinine (uCr), and urine protein:creatinine ratio (UPC) reference values, reported as the median, and lower limit (LL) and upper limit (UL), were 1.030 (1006–1.049), 17.58 (4.54–35.31) mg/dL, 154.62 (39.59–357.95) mg/dL, and 0.11 (0.07–0.16), respectively. Mass spectrometry, together with electrophoresis, revealed a pattern of common urinary proteins; albumin, lysozyme C, and ubiquitin were the most represented proteins in the giraffe urine. It has been hypothesized that these proteins could act as a defense against microbes. Moreover, in giraffes, urinalysis could be a valid tool for gauging renal function and physiological status changes.

Evaluation of Seasonal Variability of Toxic and Essential Elements in Urine Analyzed by Inductively Coupled Plasma Mass Spectrometry

Human exposure to elements is a process difficult to control and monitor. Studies on this topic usually rely on single spot urine sample to assess exposure, with the risk of ignoring variability over a longer period. In this work, we measured the urinary excretion of toxic and essential elements during 1 year with the overall goal of exploring the variability caused by seasonality on their concentration. Seven participants were recruited, and first morning urines were collected three times for each season, during November, January, April and July. Participants followed the same balanced diet during the week of collection. We then monitored nineteen essential and toxic elements in urines by inductively coupled plasma mass spectrometry. Unsupervised multivariate statistical analysis separated samples collected during summer from the ones collected during other seasons. Twelve elements had a significant seasonal variation (ANOVA test, p < 0.05) and their levels resulted increased during summer. These elements were both contaminants, such as Ni, Hg, Cd and Tl, and essential elements such as Se and Cu. However, none of these elements was detected at toxic concentration. In this study, we point out for the first time the variability of urine element concentration due to seasonality and we propose that the season of collection should be considered when providing urinary reference values of elements.

Sterile pyuria in a population of wild white‐handed gibbons (Hylobates lar)

Urinalysis is an emerging method for monitoring the health and energy balance of wild primates. Here, we report the first urinalysis of wild gibbons. We used multi-reagent test strips to monitor the health status of 52 individual white-handed gibbons (Hylobates lar) inhabiting Khao Yai National Park, Thailand. Most urinary reference values were within normal ranges; however, regardless of age- and sex-class or monthly fruit productivity, we found unexpectedly high rates of urinary leukocytes (50% and 90% of individuals in 2001-2003 and 2006, respectively). In contrast to previous studies of African apes, this finding is coupled with the near absence of urinary nitrites, demonstrating pervasive levels of sterile pyuria. This result is the first reported case of sterile pyuria in a population of wild primates. The etiology of human sterile pyuria is diverse, but in all cases it is diagnostic of systemic inflammation. We discuss the potential causes of sterile pyuria in the gibbons of Khao Yai.

Urinary Metabolic Evaluations in Normal and Stone Forming Children

Urinary stone disease is relatively rare in children and urinary metabolic evaluations have been the standard in our practice. We have previously reported a high rate of urinary metabolic abnormalities in stone forming children. We compared urinary chemistry values in normal and stone forming children. A prospective study was performed to assess urinary metabolic profiles in children with no history or a family history of urinary calculi. The 24-hour urine collections were performed and evaluated at an outside central laboratory. Urine chemistry studies were adjusted for creatinine. The data were compared to those on a historical cohort of calcium stone forming children. A total of 58 samples from normal children and 142 from stone forming children were evaluated. Mean age was 10 years in normal children and 12 years in stone forming children. of the normal and stone forming children 45% and 51%, respectively, were female. Supersaturation levels of calcium oxalate as well as calcium to creatinine levels were significantly higher in children with stones. No data confounding by age or sex was identified by stratification. There are significant differences in urinary metabolic evaluations between normal and stone forming children. This may allow more precise treatment to prevent recurrent stone episodes. We continue to perform metabolic evaluations in all children with documented urolithiasis.

PEDIATRIC STONE DISEASE: AN EVOLVING EXPERIENCE

The presentation and management of pediatric stone disease have changed due to early identification and treatment of congenital urological conditions, as well as technological advances. Therefore, we reviewed our 12-year experience. A total of 123 patients with 158 stones presented from 1991 to 2003. The 46 boys and 77 girls were 8 months to 25 years old, including 5 boys (4%) younger than 3 years, 46 (37%) 4 to 12 years old and 72 (59%) older than 13 years. A 24-hour urine collection was done in 50 patients (41%) and serum chemistry studies were performed in 66 (54%). The seasons of presentation were fall in 41% of cases, summer in 24%, spring in 22% and winter in 13%. Of the patients 94 (76%) had loin pain, 10 (8%) had urinary tract infections, 13 (11%) had a history urinary tract infection, 18 (15%) had gross hematuria, 14 (11%) had structural urological abnormalities and 7 (6%) had neurogenic bladder. Metabolic abnormalities were uncommon and included hypercalciuria in 12%, hyperoxaluria in 2% and cystinuria in 2%. A total of 57 patients (46%) passed the stones and 34 (28%) underwent extracorporeal shock wave lithotripsy, of whom 24 (71%) became stone-free. Ureteroscopy was performed in 10 patients (8%) 6 to 19 years old, percutaneous nephrostolithotomy was done in 4 (3%) and 4 (3%) underwent open surgery. Stone analysis showed calcium based in 88% of the cases, struvite in 7% and cystine in 5%. The majority of patients had no congenital abnormalities. Early diagnosis of urological abnormalities and urinary infection, and appropriate management of neurogenic bladder may have reduced the incidence in those groups. Most stones are calcium based but occur in the absence of metabolic disturbances. More patients presented in the fall, perhaps reflecting the increased concentration of urine in the summer. Half of the patients passed the stones and shock wave lithotripsy was curative in most others. Ureteroscopy, percutaneous nephrostolithotomy and open surgery were rarely required.

RESULTS OF A PROSPECTIVE TRIAL TO COMPARE NORMAL URINE SUPERSATURATION IN CHILDREN AND ADULTS

Urinary stone disease is relatively rare in children but is often due to metabolic abnormalities. Urinary supersaturation (SS) indices have been suggested as more precise predictors of stone recurrence. We previously reported urinary metabolic evaluations in stone-forming children using adult references. We now assess normal SS values in children. A prospective trial was performed to assess urinary metabolic profiles in children with no personal or family history of urinary calculi. The 24-hour urine collections were performed and evaluated at an outside central laboratory. Urine chemistries were adjusted for urine creatinine. Urine pH and SS for calcium oxalate, calcium phosphate and uric acid were also assessed. The data were compared to a cohort of normal adults. A total of 168 samples from 168 adults (58% males) and 51 samples from 30 children (59% males) were evaluated. The mean age of the children was 8.8 years (range 5 to 18). Calcium oxalate SS was similar between children and adults, and urine pH was the major cause of differences seen in the calcium phosphate and uric acid SS indices. Children had a much higher excretion of calcium, oxalate and citrate when adjusted for creatinine. There are significant differences in the normal ranges of urine chemistries in children and adults. An understanding of normal supersaturation values may allow metabolic abnormalities in stone-forming children to be more precisely diagnosed and treated.

Environmental and urinary reference values as markers of exposure to hydrocarbons in urban areas.

A study using individual dosimetry to evaluate the daily inhaled dose of sixteen aromatic and aliphatic hydrocarbons in three groups of primary school children, living in three Italian towns with 50,000 inhabitants or less, (Treviglio-Lombardy; Poggibonsi-Tuscany; Valenza-Piedmont) is presented. The simultaneous use of two passive samplers (radial diffusion) for each child, for a 24 h period, determined both the indoor and indoor + outdoor environmental reference concentrations. We measured the urinary levels of benzene, toluene, ethylbenzene and xylenes for each child and hence determined the urinary reference values for BTEX. We also considered the possibility of using benzene in urine as a biomarker of environmental exposure of the general population to this xenobiotic. We evaluated how both the environmental and biological measures were influenced by the presence of smokers in the surveyed children's houses. For the group of children living in Poggibonsi, we considered the influence of the living area and the traffic density on environmental concentrations of benzene (indoor and indoor + outdoor).