Changes In Urinary Metabolites Research Articles

Effects of Preanalytical Sample Collection and Handling on Comprehensive Metabolite Measurements in Human Urine Biospecimens.

Epidemiology studies evaluate associations between the metabolome and disease risk. Urine is a common biospecimen used for such studies due to its wide availability and non-invasive collection. Evaluating the robustness of urinary metabolomic profiles under varying preanalytical conditions is thus of interest. Here we evaluate the impact of sample handling conditions on urine metabolome profiles relative to the gold standard condition (no preservative, no refrigeration storage, single freeze thaw). Conditions tested included the use of borate or chlorhexidine preservatives, various storage and freeze/thaw cycles. We demonstrate that sample handling conditions impact metabolite levels, with borate showing the largest impact with 125 of 1048 altered metabolites (adjusted P<0.05). When simulating a case-control study with expected inconsistencies in sample handling, we predicted the occurrence of false positive altered metabolites to be low (< 11). Predicted false positives increased substantially (≥63) when cases were simulated to undergo alternate handling. Finally, we demonstrate that sample handling impacts on the urinary metabolome were markedly smaller than those in serum. While changes in urine metabolites incurred by sample handling are generally small, we recommend implementing consistent handling conditions and evaluating robustness of metabolite measurements for those showing significant associations with disease outcomes.

Biological characteristics of pregnancy in captive Yangtze finless porpoises revealed by urinary metabolomics†.

The Yangtze finless porpoises (Neophocaena asiaeorientalis a.) are an endemic and critically endangered species in China. Intensive captive breeding is essential for understanding the biology of critically endangered species, especially their pregnancy characteristics, knowledge of which is crucial for effective breeding management. Urine metabolomics can reveal metabolic differences, arising from physiological changes across pregnancy stages. Therefore, we used the urinary metabolomic technology, to explore urinary metabolite changes in pregnant Yangtze finless porpoises. A total of 2281 metabolites were identified in all samples, which including organic acids and derivatives (24.45%), organoheterocyclic compounds (20.23%), benzenoids (18.05%), organic oxygen compounds (7.73%), and phenylpropanoids and polyketides (6.48%). There were 164, 387, and 522 metabolites demonstrating differential abundance during early pregnancy, mid pregnancy, and late pregnancy, respectively, from the levels observed in nonpregnancy. The levels of pregnenolone, 17α-hydroxyprogesterone, and tetrahydrocortisone were significantly higher during all pregnancy stages, indicating their important roles in fetal development. The differential metabolites between nonpregnancy and pregnancy were mainly associated with amino acid and carbohydrate metabolism. Moreover, metabolic activity varied across pregnancy stages; steroid hormone biosynthesis was predominant in early pregnancy, and amino acid biosynthesis and carbohydrate metabolism were predominant in mid pregnancy and late pregnancy, respectively. Our results provide new insights into metabolic characteristics in the Yangtze finless porpoises' urine during pregnancy, and indicate that the differential levels of urine metabolites can determine pregnancy in Yangtze finless porpoises, providing valuable information for the husbandry and management of pregnant Yangtze finless porpoises in captivity.

Targeting metabolic pathways: a novel therapeutic direction for type 2 diabetes.

Type 2 diabetes mellitus (T2DM) is a prevalent metabolic disease that causes multi-organ complications, seriously affecting patients' quality of life and survival. Understanding its pathogenesis remains challenging, with current clinical treatment regimens often proving ineffective. In this study, we established a mouse model of T2DM and employed 16s rDNA sequencing to detect changes in the species and structure of gut flora. Additionally, we used UPLC-Q-TOF-MS to identify changes in urinary metabolites of T2DM mice, analyzed differential metabolites and constructed differential metabolic pathways. Finally, we used Pearman correlation analysis to investigate the relationship between intestinal flora and differential metabolites in T2DM mice, aiming to elucidate the pathogenesis of T2DM and provide an experimental basis for its clinical treatment. Our findings revealed a reduction in both the species diversity and abundance of intestinal flora in T2DM mice, with significantly decreased levels of beneficial bacteria such as Lactobacillus and significantly increased levels of harmful bacteria such as Helicobacter pylori. Urinary metabolomics results identified 31 differential metabolites between T2DM and control mice, including Phosphatidylcholine, CDP-ethanolamine and Leukotriene A4, which may be closely associated with the glycerophospholipid and arachidonic acid pathways. Pearman correlation analysis showed a strong correlation between dopamine and gonadal, estradiol and gut microbiota, may be a novel direction underlying T2DM. In conclusion, our study suggests that alterations in gut microbiota and urinary metabolites are characteristic features of T2DM in mice. Furthermore, a strong correlation between dopamine, estradiol and gut microbiota, may be a novel direction underlying T2DM, the aim is to provide new ideas for clinical treatment and basic research.

Analysis of the urinary metabolic profiles in irradiated rats treated with Activated Protein C (APC), a potential mitigator of radiation toxicity

Purpose The goal of the current study was to identify longitudinal changes in urinary metabolites following IR exposure and to determine potential alleviation of radiation toxicities by administration of recombinant APC formulations. Materials and methods Female adult WAG/RijCmcr rats were irradiated with 13.0 Gy leg-out partial body X-rays; longitudinally collected urine samples were subject to LC-MS based metabolomic profiling. Sub-cohorts of rats were treated with three variants of recombinant APC namely, rat wildtype (WT) APC, rat 3K3A mutant form of APC, and human WT APC as two bolus injections at 24 and 48 hours post IR. Results Radiation induced robust changes in the urinary profiles leading to oxidative stress, severe dyslipidemia, and altered biosynthesis of PUFAs, glycerophospholipids, sphingolipids, and steroids. Alterations were observed in multiple metabolic pathways related to energy metabolism, nucleotide biosynthesis and metabolism that were indicative of disrupted mitochondrial function and DNA damage. On the other hand, sub-cohorts of rats that were treated with rat wildtype-APC showed alleviation of radiation toxicities, in part, at the 90-day time point, while rat 3K3A-APC showed partial alleviation of radiation induced metabolic alterations 14 days after irradiation. Conclusions Taken together, these results show that augmenting the Protein C pathway and activity via administration of recombinant APC may be an effective approach for mitigation of radiation induced normal tissue toxicity.

A scoping review: urinary markers of metabolic maturation in infants with CHD and the relationship to growth.

Growth failure in infants born with CHD is a persistent problem, even in those provided with adequate nutrition. To summarise the published data describing the change in urinary metabolites during metabolic maturation in infants with CHD and identify pathways amenable to therapeutic intervention. Scoping review. Studies using qualitative or quantitative methods to describe urinary metabolites pre- and post-cardiac surgery and the relationship with growth in infants with CHD. NICE Healthcare Databases website was used as a tool for multiple searches. 347 records were identified, of which 37 were duplicates. Following the removal of duplicate records, 310 record abstracts and titles were screened for inclusion. The full texts of eight articles were reviewed for eligibility, of which only two related to infants with CHD. The studies included in the scoping review described urinary metabolites in 42 infants. A content analysis identified two overarching themes of metabolic variation predictive of neurodevelopmental abnormalities associated with anaerobic metabolism and metabolic signature associated with the impact on gut microbiota, inflammation, energy, and lipid digestion. The results of this scoping review suggest that there are considerable gaps in our knowledge relating to metabolic maturation of infants with CHD, especially with respect to growth. Surgery is a key early life feature for CHD infants and has an impact on the developing biochemical phenotype with implications for metabolic pathways involved in immunomodulation, energy, gut microbial, and lipid metabolism. These early life fingerprints may predict those individuals at risk for neurodevelopmental abnormalities.

Metabolomics and network pharmacological analysis to explore the mechanism of ginseng treatment for spleen-qi deficiency.

Ginseng is the main Chinese herbal medicine for tonifying Qi and invigorating the spleen. It has been used to treat spleen-qi deficiency with good protective effects for thousands of years, however, its biological mechanism has not been fully elucidated. This study aims to explore the mechanism of ginseng in the treatment of spleen-qi deficiency by using a comprehensive method combining metabolomics and network pharmacological analysis. Gas chromatography-mass spectroscopy was applied for investigating the changes in urine metabolites in spleen-qi deficiency rats and after treatment with ginseng. Metabolomics and network pharmacology analysis were applied to screen potential biomarkers and therapeutic targets of ginseng in the treatment of spleen-qi deficiency, respectively. Molecular docking was employed to further evaluate the docking mode of potential biomarkers and therapeutic target proteins. The results of metabolomics showed that the therapeutic effects of ginseng are mainly related to its regulation of three metabolic pathways. The molecular structure of potential biomarkers and common proteins was further analyzed by molecular docking to verify its effectiveness. Ginseng has good pharmacological effects by controlling key targets of related metabolic pathways, signal pathways, and potential biomarkers.

A Scoping Review: Urinary Markers of Metabolic Maturation in Preterm Infants and Future Interventions to Improve Growth.

Background: Growth failure in infants born preterm is a significant issue, increasing the risk of poorer neurodevelopmental outcomes and metabolic syndrome later in life. During the first 1000 days of life biological systems mature rapidly involving developmental programming, cellular senescence, and metabolic maturation, regulating normal growth and development. However, little is known about metabolic maturation in infants born preterm and the relationship with growth. Objective: To examine the available evidence on urinary markers of metabolic maturation and their relationship with growth in infants born preterm. Eligibility criteria: Studies including in this scoping review using qualitative or quantitative methods to describe urinary markers of metabolic maturation and the relationship with growth in infants born preterm. Results: After a screening process 15 titles were included in this review, from 1998–2021 drawing from China (n = 1), Italy (n = 3), Germany (n = 3), Greece (n = 1), Japan (n = 2), Norway (n = 1), Portugal (n = 1), Spain (n = 2) and USA (n = 1). The included studies examined urinary metabolites in 1131 infants. A content analysis identified 4 overarching themes relating to; (i) metabolic maturation relative to gestational age, (ii) metabolic signature and changes in urinary metabolites over time, (iii) nutrition and (iv) growth. Conclusion: The results of this scoping review suggest there are considerable gaps in our knowledge relating to factors associated with metabolic instability, what constitutes normal maturation of preterm infants, and how the development of reference phenome age z scores for metabolites of interest could improve nutritional and growth outcomes.

A Feasibility Study to Evaluate Changes in Urinary Metabolites after OnabotulinumtoxinA Injection for Refractory Overactive Bladder.

Metabolomics analysis of urine before and after overactive bladder (OAB) treatment may demonstrate a unique molecular profile, allowing predictions of responses to treatment. This feasibility study aimed to correlate changes in urinary metabolome with changes in OAB symptoms after intravesical onabotulinumtoxinA (BTX-A) injections for refractory OAB. Women 18 years or older with non-neurogenic refractory OAB were recruited to complete OAB-V8 questionnaires and submit urine samples before and after 100 units intravesical BTX-A injection. Samples were submitted to CE-TOFMS metabolomics profiling. Data were expressed as percent of change from pre-treatment and were correlated with OAB-V8 score improvement. Urinary metabolite changes in the OAB-V8 groups were compared using the Kruskal–Wallis test, and associations between metabolites and OAB-V8 scores were examined using quantile regression analysis. Of 61 urinary metabolites commonly detected before and after BTX-A, there was a statistically significant decrease in adenosine and an increase in N8-acetylspermidine and guanidinoacetic acid levels associated with OAB score improvement, suggesting that intravesical BTX-A injection modifies the urinary metabolome. These urinary metabolites could provide insight into OAB pathophysiology and help identify patients who would benefit most from chemodenervation.

Change in Urinary Myoinositol/Citrate Ratio Associates with Progressive Loss of Renal Function in ADPKD Patients

Introduction: In autosomal dominant polycystic kidney disease (ADPKD) patients, predicting renal disease progression is important to make a prognosis and to support the clinical decision whether to initiate renoprotective therapy. Conventional markers all have their limitations. Metabolic profiling is a promising strategy for risk stratification. We determined the prognostic performance to identify patients with a fast progressive disease course and evaluated time-dependent changes in urinary metabolites. Methods: Targeted, quantitative metabolomics analysis (¹H NMR-spectroscopy) was performed on spot urinary samples at two time points, baseline (n = 324, 61% female; mean age 45 years, SD 11; median eGFR 61 mL/min/1.73 m², IQR 42–88; mean years of creatinine follow-up 3.7, SD 1.3) and a sample obtained after 3 years of follow-up (n = 112). Patients were stratified by their eGFR slope into fast and slow progressors based on an annualized change of > −3.0 or ≤ −3.0 mL/min/1.73 m²/year, respectively. Fifty-five urinary metabolites and ratios were quantified, and the significant ones were selected. Logistic regression was used to determine prognostic performance in identifying those with a fast progressive course using baseline urine samples. Repeated-measures ANOVA was used to analyze whether changes in urinary metabolites over a 3-year follow-up period differed between fast and slow progressors. Results: In a single urinary sample, the prognostic performance of urinary metabolites was comparable to that of a model including height-adjusted total kidney volume (htTKV, AUC = 0.67). Combined with htTKV, the predictive value of the metabolite model increased (AUC = 0.75). Longitudinal analyses showed an increase in the myoinositol/citrate ratio (p < 0.001) in fast progressors, while no significant change was found in those with slow progression, which is in-line with an overall increase in the myoinositol/citrate ratio as GFR declines. Conclusion: A metabolic profile, measured at a single time point, showed at least equivalent prognostic performance to an imaging-based risk marker in ADPKD. Changes in urinary metabolites over a 3-year follow-up period were associated with a fast progressive disease course.

Blood pressure and urine metabolite changes in spontaneously hypertensive rats treated with leaf extract of Ficus deltoidea var angustifolia

Ficus deltoidea var angustifolia (FD-A) reduces blood pressure in spontaneously hypertensive rats (SHR) but the mechanism remains unknown. Changes in urine metabolites following FD-A treatment in SHR were, therefore, examined to identify the mechanism of its antihypertensive action. Male SHR were given either FD-A (1000 mg kg−1 day−1) or losartan (10 mg kg−1 day−1) or 0.5 mL of ethanolic-water (control) daily for 4 weeks. Systolic blood pressure (SBP) was measured every week and urine spectra data acquisition, on urine collected after four weeks of treatment, were compared using multivariate data analysis. SBP in FD-A and losartan treated rats was significantly lower than that in the controls after four weeks of treatment. Urine spectra analysis revealed 24 potential biomarkers with variable importance projections (VIP) above 0.5. These included creatine, hippurate, benzoate, trimethylamine N-oxide, taurine, dimethylamine, homocysteine, allantoin, methylamine, n-phenylacetylglycine, guanidinoacetate, creatinine, lactate, glucarate, kynurenine, ethanolamine, betaine, 3-hydroxybutyrate, glycine, lysine, glutamine, 2-hydroxyphenylacetate, 3-indoxylsulfate and sarcosine. From the profile of these metabolites, it seems that FD-A affects urinary levels of metabolites like taurine, hypotaurine, glycine, serine, threonine, alanine, aspartate and glutamine. Alterations in these and the pathways involved in their metabolism might underlie the molecular mechanism of its antihypertensive action.

Carbon Ion Radiotherapy Evokes a Metabolic Reprogramming and Individualized Response in Prostate Cancer.

Introduction: Carbon ion radiotherapy (CIRT) is a novel treatment for prostate cancer (PCa). However, the underlying mechanism for the individualized response to CIRT is still not clear. Metabolic reprogramming is essential for tumor growth and proliferation. Although changes in metabolite profiles have been detected in patients with cancer treated with photon radiotherapy, there is limited data regarding CIRT-induced metabolic changes in PCa. Therefore, the study aimed to investigate the impact of metabolic reprogramming on individualized response to CIRT in patients with PCa.Materials and Methods: Urine samples were collected from pathologically confirmed patients with PCa before and after CIRT. A UPLC-MS/MS system was used for metabolite detection. XCMS online, MetDNA, and MS-DIAL were used for peak detection and identification of metabolites. Statistical analysis and metabolic pathway analysis were performed on MetaboAnalyst.Results: A total of 1,701 metabolites were monitored in this research. Principal component analysis (PCA) revealed a change in the patient's urine metabolite profiles following CIRT. Thirty-five metabolites were significantly altered, with the majority of them being amino acids. The arginine biosynthesis and histidine metabolism pathways were the most significantly altered pathways. Hierarchical cluster analysis (HCA) showed that after CIRT, the patients could be clustered into two groups according to their metabolite profiles. The arginine biosynthesis and phenylalanine, tyrosine, and tryptophan biosynthesis pathways are the most significantly discriminated pathways.Conclusion: Our preliminary findings indicate that metabolic reprogramming and inhibition are important mechanisms involved in response to CIRT in patients with PCa. Therefore, changes in urine metabolites could be used to timely assess the individualized response to CIRT.

Urinary metabolomic signatures as indicators of injury severity following traumatic brain injury: A pilot study.

BackgroundAnalysis of fluid metabolites has the potential to provide insight into the neuropathophysiology of injury in patients with traumatic brain injury (TBI).ObjectiveUsing a 1H nuclear magnetic resonance (NMR)-based quantitative metabolic profiling approach, this study determined (1) if urinary metabolites change during recovery in patients with mild to severe TBI; (2) whether changes in urinary metabolites correlate to injury severity; (3) whether biological pathway analysis reflects mechanisms that mediate neural damage/repair throughout TBI recovery.MethodsUrine samples were collected within 7 days and at 6-months post-injury in male participants (n = 8) with mild-severe TBI. Samples were analyzed with NMR-based quantitative spectroscopy for metabolomic profiles and analyzed with multivariate statistical and machine learning-based analyses.ResultsLower levels of homovanillate (R = −0.74, p ≤ 0.001), L-methionine (R = −0.78, p < 0.001), and thymine (R = −0.85, p < 0.001) negatively correlated to injury severity. Pathway analysis revealed purine metabolism to be a primary pathway (p < 0.01) impacted by TBI.ConclusionThis study provides pilot data to support the use of urinary metabolites in clinical practice to better interpret biochemical changes underlying TBI severity and recovery. The discovery of urinary metabolites as biomarkers may assist in objective and rapid identification of TBI severity and prognosis. Thus, 1H NMR metabolomics has the potential to facilitate the adaptation of treatment programs that are personalized to the patient’s needs.

P62.04 Metabolic Profile of Urine of Early Stage Non Small Cell Lung Cancer Patients Before and After Surgical Resection Using Mass Spectrometry

Despite curative resection of early-stage Non-Small Cell Lung Cancer (NSCLC), many patients can experience recurrence and are thus subjected to surveillance with repeated imaging tests. We aimed to understand the cellular metabolic processes involved in tumor initiation, progression, and metastasis. We hypothesized that non-invasive monitoring of urinary metabolites would allow the detection of metabolic changes in response to treatment and can thereafter be used for surveillance of recurrence. Our current study aimed to assess the changes in urinary metabolites in response to surgical removal of the tumor.

Urinary biomarkers indicative of recovery from spinal cord injury: A pilot study.

Current assessments of recovery following spinal cord injury (SCI) focus on clinical outcome measures. These assessments bear an inherent risk of bias, emphasizing the need for more reliable prognostic biomarkers to measure SCI severity. This study evaluated fluid biomarkers as an objective tool to aid with prognosticating outcomes following SCI. Using a 1H nuclear magnetic resonance (NMR)-based quantitative metabolomics approach of urine samples, the objectives were to determine (a) if alterations in metabolic profiles reflect the extent of recovery of individual SCI patients, (b) whether changes in urine metabolites correlate to patient outcomes, and (c) whether biological pathway analysis reflects mechanisms of neural damage and repair. An inception cohort exploratory pilot study collected morning urine samples from male SCI patients (n=6) following injury and again at 6-months post-injury. A 700 MHz Bruker Avance III HD NMR spectrometer was used to acquire the metabolic signatures of urine samples, which were used to derive metabolic pathways. Multivariate statistical analyses were used to identify changes in metabolic signatures, which were correlated to clinical outcomes in the Spinal Cord Independence Measure (SCIM). Among SCI-induced metabolic changes, biomarkers which significantly correlated to patient SCIM scores included caffeine (R = -0.76, p < 0.01), 3-hydroxymandelic acid (R= -0.85, p < 0.001), L-valine (R = 0.90, p < 0.001; R = -0.64, p < 0.05), and N-methylhydantoin (R = -0.90, p < 0.001). The most affected pathway was purine metabolism. These findings indicate that urinary metabolites reflect SCI lesion severity and recovery and provide potentially prognostic biomarkers of SCI outcome in precision medicine approaches.

Untargeted Urinary Metabolomics and Children's Exposure to Secondhand Smoke: The Influence of Individual Differences.

Children’s exposure to secondhand smoke (SHS) is a severe public health problem. There is still a lack of evidence regarding panoramic changes in children’s urinary metabolites induced by their involuntary exposure to SHS, and few studies have considered individual differences. This study aims to clarify the SHS-induced changes in urinary metabolites in preschool children by using cross-sectional and longitudinal metabolomics analyses. Urinary metabolites were quantified by using untargeted ultra high-performance liquid chromatography-mass spectrometry (UPLC(c)-MS/MS). Urine cotinine-measured SHS exposure was examined to determine the exposure level. A cross-sectional study including 17 children in a low-exposure group, 17 in a medium-exposure group, and 17 in a high-exposure group was first conducted. Then, a before–after study in the cohort of children was carried out before and two months after smoking-cessation intervention for family smokers. A total of 43 metabolites were discovered to be related to SHS exposure in children in the cross-sectional analysis (false discovery rate (FDR) corrected p < 0.05, variable importance in the projection (VIP) > 1.0). Only three metabolites were confirmed to be positively associated with children’s exposure to SHS (FDR corrected p < 0.05) in a follow-up longitudinal analysis, including kynurenine, tyrosyl-tryptophan, and 1-(3-pyridinyl)-1,4-butanediol, the latter of which belongs to carbonyl compounds, peptides, and pyridines. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that 1-(3-pyridinyl)-1,4-butanediol and kynurenine were significantly enriched in xenobiotic metabolism by cytochrome P450 (p = 0.040) and tryptophan metabolism (p = 0.030), respectively. These findings provide new insights into the pathophysiological mechanism of SHS and indicate the influence of individual differences in SHS-induced changes in urinary metabolites in children.

Coffee consumption revealed sex differences in host endogenous metabolism and gut microbiota in healthy adults.

Coffee is rich in antioxidant and has been shown to confer various health benefits. Here, we investigated the effect of single-dose coffee consumption in healthy human subjects. About 30 healthy volunteers were recruited and given a serving of sugar free black coffee. Urine and fecal samples were collected and analyzed. Significant changes in urinary metabolites relating to coffee, gut microbial and host energy metabolisms were observed post-coffee consumption. Clear sex differences were also observed in the urinary metabolic profiles pre- and post-coffee consumption. Sex differences in richness and composition of gut microbiota were observed, however, the effect of single-dose coffee consumption on host gut microbiota were unremarkable. These findings indicated that single-dose coffee consumption affects sex-specific host metabolic responses that relates to gut-microbe and energy metabolism. This study demonstrated the utility of systems biology tools to unravel complexity of host-diet biology and gut microbial responses. PRACTICAL APPLICATIONS: This study demonstrated that integrated systems biology approach enabled efficient extractions of host biochemical and microbial information that allows food industry to ascertain the impact of diet and longitudinal assessment of potential functional food in humans.

An NMR-Based Approach to Identify Urinary Metabolites Associated with Acute Physical Exercise and Cardiorespiratory Fitness in Healthy Humans-Results of the KarMeN Study.

Knowledge on metabolites distinguishing the metabolic response to acute physical exercise between fit and less fit individuals could clarify mechanisms and metabolic pathways contributing to the beneficial adaptations to exercise. By analyzing data from the cross-sectional KarMeN (Karlsruhe Metabolomics and Nutrition) study, we characterized the acute effects of a standardized exercise tolerance test on urinary metabolites of 255 healthy women and men. In a second step, we aimed to detect a urinary metabolite pattern associated with the cardiorespiratory fitness (CRF), which was determined by measuring the peak oxygen uptake (VO2peak) during incremental exercise. Spot urine samples were collected pre- and post-exercise and 47 urinary metabolites were identified by nuclear magnetic resonance (NMR) spectroscopy. While the univariate analysis of pre-to-post-exercise differences revealed significant alterations in 37 urinary metabolites, principal component analysis (PCA) did not show a clear separation of the pre- and post-exercise urine samples. Moreover, both bivariate correlation and multiple linear regression analyses revealed only weak relationships between the VO2peak and single urinary metabolites or urinary metabolic pattern, when adjusting for covariates like age, sex, menopausal status, and lean body mass (LBM). Taken as a whole, our results show that several urinary metabolites (e.g., lactate, pyruvate, alanine, and acetate) reflect acute exercise-induced alterations in the human metabolism. However, as neither pre- and post-exercise levels nor the fold changes of urinary metabolites substantially accounted for the variation of the covariate-adjusted VO2peak, our results furthermore indicate that the urinary metabolites identified in this study do not allow to draw conclusions on the individual’s physical fitness status. Studies investigating the relationship between the human metabolome and functional variables like the CRF should adjust for confounders like age, sex, menopausal status, and LBM.

An Examination of Changes in Urinary Metabolites and Behaviors with the Use of Leucovorin Calcium in Children with Autism Spectrum Disorder (ASD)

Children with autism spectrum disorder (ASD) have been found to have a high prevalence of folate receptor auto-antibodies (FRAA), which may impair the normal transport of folate from blood into the cerebrospinal fluid (CSF). Leucovorin calcium (LC) is believed to bypass the folate transport system and restore function. We sought to examine changes in behavior and urinary metabolites in children and young adults with ASD being treated with LC. Students attending a K-12 school for ASD were recruited for an open-label, 12-week study of high-dose LC (2 mg/kg/day, max dose 50 mg/day). The primary outcome measures were the mean changes in the Aberrant Behavior Checklist (ABC) and the Social Responsiveness Scale (SRS). We also examined changes in Pediatric Quality of Life (PedsQL) and urinary metabolites. Changes were assessed with paired sample t-tests. Twelve students aged 13 to 19 (2 girls, 10 boys) completed the study. The parent-reported SRS showed a non-significant decrease (improvement) of 7.8 points (95% CI − 1.6 to 17.3, p = 0.095), and the ABC showed a non-significant decrease of 2.4 points (95% CI − 6.4 to 11.3, p = 0.56). The teacher-reported ABC and the parent-reported PedsQL showed very little change. Urinary metabolites with the greatest changes were involved in folate, phosphatidylcholine, and tocopherol metabolism. In an open-label study of school-aged children with ASD, LC treatment did not lead to significant improvements. The parent-reported SRS showed a non-significant improvement of 7.8 points, which is clinically important and worthy of future study with larger samples. The potential benefits of LC may be limited to children with a specific physiological abnormality (e.g., FRAA status) and may require a targeted treatment approach. Urinary metabolites may be a useful tool to identify children who are likely to respond to treatment.

Nontargeted urine metabolomics analysis of the protective and therapeutic effects of Citri Reticulatae Chachiensis Pericarpium on high-fat feed-induced hyperlipidemia in rats.

In this study, we focused on studying the changes in urine metabolites in hyperlipidemic rats using ultra-performance liquid chromatography coupled with quadrupole time-of-fight mass spectrometry (UPLC-Q-TOF/MS) and metabolomics, as well as the effect of Citri Reticulatae Chachiensis Pericarpium (CRCP) on hyperlipidemia. These urine samples were examined by UPLC-Q-TOF/MS to obtain MS data. The MS data were analyzed by principal component analysis and partial least squares-discriminant analysis to identify the differential metabolites. CRCP reduced the body weight and levels of triglycerides, total cholesterol and low-density lipoprotein cholesterol and abnormally decreased high-density lipoprotein cholesterol in hyperlipidemic rats, which were significantly raised by a high-fat diet. Twenty-seven potential biomarkers were identified within the complex sample matrix of urine. Fourteen biomarkers increased in the hyperlipidemia rats compared with normal rats. Meanwhile, 13 biomarkers decreased. CRCP reversed abnormal changes in biomarkers, including 5-l-glutamyl-taurine, 5-aminopentanoic acid, cis-4-octenedioic acid and 2-octenedioic acid. These biomarkers show that hyperlipidemia is related to the metabolic pathways of taurine and hypotaurine metabolism, fatty acid biosynthesis, and arginine and proline metabolism. CRCP mainly prevents hyperlipidemia by intervening in these metabolic pathways.

Phthalate exposure and childhood overweight and obesity: Urinary metabolomic evidence

ObjectiveMetabolomics may unravel global metabolic changes in response to environmental exposures and identify important biological pathways involved in the pathophysiology of childhood obesity. Phthalate has been considered an obesogen and contributing to overweight and obesity in children. The purpose of this study is to evaluate changes in urine metabolites in response to the environmental phthalate exposure among overweight or obese children, and to investigate the metabolic mechanisms involved in the obesogenic effect of phthalate on children at puberty. MethodsWithin the national Puberty Timing and Health Effects in Chinese Children (PTHEC) study, 69 overweight/obese children and 80 normal weight children were selected into the current study according to their puberty timing and WGOC (The Working Group for obesity in China) references. Urinary concentrations of six phthalate monoesters (MMP, MEP, MnBP, MEHP, MEOHP and MEHHP) were measured using API 2000 electrospray triple quadrupole mass spectrometer (ESIMS/MS). Metabolomic profiling of spot urine was performed using gas chromatography-mass spectrometry. Differentially expressed urinary metabolites associated with phthalate monoesters exposure were examined using orthogonal partial least square-discriminant analysis and multiple linear regression models. In addition, the candidate metabolites were regressed to obesity indices with multiple linear regression models and logistic regression models in all subjects. ResultsCompared with normal weight children, higher levels of MnBP were detected in urinary samples of children with overweight and obesity. After adjusting for confounders including chronological age, gender, puberty onset, daily energy intake and physical activity and socio-economic level, positive association remained between urinary MnBP concentration and childhood overweight/obesity [OR = 1.586, 95% CI:1.043,2.412]. We observed elevated MnBP concentration was significantly correlated with increased levels of monostearin, 1-monopalmitin, stearic acid, itaconic acid, glycerol 3-phosphate, 5-methoxytryptamine, kyotorphin, 1-methylhydantoin, d-alanyl-d-alanine, pyrrole-2-carboxylic acid, 3,4-Dihydroxyphenylglycol, and butyraldehyde. Meanwhile, increased MnBP concentration was also significantly correlated with decreased levels of lactate, glucose 6-phosphate, d-fructose 6-phosphate, palmitic acid, 4-acetamidobutyric acid, l-glutamic acid, n-acetyl-l-phenylalanine, iminodiacetic acid, hydroxyproline, pipecolinic acid, l-ornithine, n-acetyl-l-glutamic acid, guanosine, cytosin, and (s)-mandelic acid in the normal weight subjects. The observations indicated that MnBP exposure was related to global urine metabolic abnormalities characterized by disrupting arginine and proline metabolism and increasing oxidative stress and fatty acid reesterification. Among the metabolic markers related to MnBP exposure, 1-methylhydantoin, pyrrole-2-carboxylic acid and monostearin were found to be positively correlated with obesity indices, while hydroxyproline, l-ornithine, and lactate were negatively associated with overweight/obesity in children. ConclusionsOur results suggested that the disrupted arginine and proline metabolism associated with phthalate exposure might contribute to the development of overweight and obesity in school-age children, providing insights into the pathophysiological changes and molecular mechanisms involved in childhood obesity.