Reference intervals for 24 laboratory parameters determined in 24-hour urine collections

Abstract

BACKGROUND: Reference intervals for many laboratory parameters determined in 24-h urine collections are either not publicly available or based on small numbers, not sex specific or not from a representative sample. METHODS: Osmolality and concentrations or enzymatic activities of sodium, potassium, chloride, glucose, creatinine, citrate, cortisol, pancreatic -amylase, total protein, albumin, transferrin, immunoglobulin G, 1-microglobulin, 2-macroglobulin, as well as porphyrins and their precursors ( -aminolevulinic acid and porphobilinogen) were determined in 241 24-h urine samples of a population-based cohort of asymptomatic adults (121 men and 120 women). For 16 of these 24 parameters creatinine-normalized ratios were calculated based on 24-h urine creatinine. The reference intervals for these parameters were calculated according to the CLSI C28-A3 statistical guidelines. RESULTS: By contrast to most published reference intervals, which do not stratify for sex, reference intervals of 12 of 24 laboratory parameters in 24-h urine collections and of eight of 16 parameters as creatininenormalized ratios differed significantly between men and women. For six parameters calculated as 24-h urine excretion and four parameters calculated as creatinine-normalized ratios no reference intervals had been published before. For some parameters we found significant and relevant deviations from previously reported reference intervals, most notably for 24-h urine cortisol in women. Ten 24-h urine parameters showed weak or moderate sex-specific correlations with age. CONCLUSIONS: By applying up-to-date analytical methods and clinical chemistry analyzers to 24-h urine collections from a large populationbased cohort we provide as yet the most comprehensive set of sex-specific reference intervals calculated according to CLSI guidelines for parameters determined in 24-h urine collections. AbstractBackground: Reference intervals for many laboratory parameters determined in 24-h urine collections are either not publicly available or based on small numbers, not sex specific or not from a representative sample. Methods: Osmolality and concentrations or enzymatic activities of sodium, potassium, chloride, glucose, creatinine, citrate, cortisol, pancreatic α-amylase, total protein, albumin, transferrin, immunoglobulin G, α 1 -microglobulin, α 2 -macroglobulin, as well as porphyrins and their precursors (δ-aminolevulinic acid and porphobilinogen) were determined in 241 24-h urine samples of a population-based cohort of asymptomatic adults (121 men and 120 women). For 16 of these 24 parameters creatininenormalized ratios were calculated based on 24-h urine creatinine. The reference intervals for these parameters were calculated according to the CLSI C28-A3 statistical guidelines. Results: By contrast to most published reference intervals, which do not stratify for sex, reference intervals of 12 of 24 laboratory parameters in 24-h urine collections and of eight of 16 parameters as creatinine-normalized ratios differed significantly...

Metabolomic Profiling of Human Urine as a Screen for Multiple Inborn Errors of Metabolism

“…One important consideration of the use of urine as a surrogate sample type for plasma is the well-established practice of normalization. There is rich debate about the appropriate method for normalization of urine samples (Morgenstern et al, 2003;Dieterle et al, 2006;Warrack et al, 2009;Godevithanage et al, 2010;Wagner et al, 2010;Ryan et al, 2011;Schrier, 2011;Veselkov et al, 2011;Kohl et al, 2012;Armstrong et al, 2013;Edmands et al, 2014;Curcio et al, 2015;Souza et al, 2015). Normalizing accounts for different variables such as hydration status of samples was by scaling the spectral data to the same virtual overall concentration.…”

Chronic Stress in Children and Adolescents: A Review of Biomarkers for Use in Pediatric Research

“…Measurement of urinary free cortisol (UFC) offers an advantage over serum and salivary cortisol as it provides an index of adrenocortical activity over a 24-hr period. While cortisol measured at a single time point may reflect momentary stressors or fluctuations in circadian rhythm, UFC collected over 24 hr provides a more stable assessment of adrenocortical activity over time (Curcio et al, 2016; Gomez, Malozowski, Winterer, Vamvakopoulos, & Chrousos, 1991). UFC is commonly measured to diagnose conditions associated with abnormal adrenocortical activity, such as Cushing syndrome, congenital adrenal hyperplasia, or adrenal insufficiency (Taylor, Machacek, & Singh, 2002).…”

Dietary reference values for chloride

“…In view of the low content of chloride in unprocessed (unsalted) foods relative to the levels of consumption of sodium chloride in Western countries, sodium chloride (from processed food and discretionary use) is considered to be the principal source of dietary chloride in Western diets. In studies which involved individuals consuming their habitual diet, the levels of excretion of sodium and chloride, in mmol/day, were found to be similar (Sanchez‐Castillo et al., ; Kübler, ; Wang et al., ; Curcio et al., ; Terry et al., ) (Appendix B.1). Differences (in mmol) in urinary excretions of sodium and chloride become more prominent when a no‐ or low‐salt diet is consumed (Dole et al., , ; Oliver et al., ).…”

“…Na+ measured using flame‐photometry and Cl‐ measured by colorimetryMen (Q1)167143.0304.6143.5266.9Men (Q2)178173.5344.3167.9360.3Men (Q3)181198.5393.0191.7352.7Men (Q4)167202.4339.8191.1334.8Women (Q1)224110.9288.5104.0264.4Women (Q2)245132.3–127.5244.3Women (Q3)244138.1–125.5280.0Women (Q4)233153.1–152.8283.3 Curcio et al. () Switzerland Median Median Single 24‐h urinary collection. Participants with an estimated GFR < 60 mL/min/1.7...…”