Urinary Organic Acids Quantitated in a Healthy North Indian Pediatric Population

Abstract

Human urine gives evidence of the metabolism in the body and contains numerous organic acids and other compounds at a variety of concentration. The concentration of organic acids in urine varies from population to population due to genotype, food habits and other epigenetic and environmental influences. Knowledge of the reference values for urinary organic acids in a healthy pediatric population is very important for critical evaluation. This study was designed to quantify 16 organic acids in a healthy north Indian pediatric population. Early morning urine samples from healthy pediatric subjects of age 1 day to 16 years who did not have symptoms of any disease were analyzed for organic acid content. The children were not on any supplemental vitamins or drugs and were on a free and unrestricted diet. The creatinine concentration of each sample was determined before organic acid analysis. Organic acids were extracted from urine with ethyl acetate, extracted residue was air dried, converted into trimethylsilyl derivatives and analysed by gas chromatography mass spectrometry. Here we reported the age wise mean values and standard deviations for each compound, adjusted for creatinine content (mmol/mol of creatinine). We found the concentration of most of the metabolites are higher in our population in comparison to other populations. Such data may help to provide a basis for diagnosing metabolic abnormalities in patients in a specific ethnicity.

Influence of Sex on Urinary Organic Acids: A Cross-Sectional Study in Children

“…The endocrine system is different in males and females and this could explain, at least partially, why urinary organic acids show more sex-related differences in the first group of age. In line with previous results [16,31,32], sex differences decrease with age but the single age group presents some specificity. It is also evidenced that age effect is greater in males than in females.…”

“…The influence of age on few urinary metabolites has been described in children [16][17][18], and in adults [13,19,20]. For example, creatinine increases with age, while creatine, glycine, citrate, succinate, and acetone show a negative correlation with age in 12 year old children [18], while lactate, citrate succinate, N-acetylglutamic acid, dimethylamine, glutamine, 1-methylnicotinamide decrease with age in children from 6 months to 4 years of age [17].…”

Metabolic Impact of Infant Formulas in Young Infants. An Outlook From the Urine Metabolome

“…The metabolism is affected directly by the alimentation pattern of the individual, for example, it has been observed that food composition, additives and preservers in uence the metabolite excretion pattern in urine favoring the excretion of metabolites like D-glucitol, 4-Hydroxybenzoic acid, oxalic acid, vanillactate, among others 14,15 . In fact, studies performed mainly in adults and children have demonstrated that speci c dietary habits, due to cultural background or age, may in uence the organic acid excretion pro le 12,15 . Newborn population is exposed to different class of nutrients according to their food, thus, it is important to generate a deeper knowledge of newborn metabolism and the metabolites normally excreted in urine and the impact of diet on them.…”

“…Up to now some studies have been conducted exploring the effect of infant formula based nutrition on newborn intestinal function 7 , immunological system development 11 , association to allergies and infectious diseases, and duration of breastfeeding 12,13 , however there is limited evidence in the literature about how these formulas in uence the newborn metabolism. Recently, Slupsky et.al evaluated the postprandial metabolic response of newborns to diets consisting of either infant formulas with or without lactose versus breast feeding, observing an increase of plasmatic levels of glucose, insulin and amino acid in infants fed with formulas 11 .…”

Application of metabolomics: Focus on the quantification of organic acids in healthy adults

“…Given the fact that metabolomics reflects the phenotype and is sensitive to genetic, epigenetic and environmental factors, such as diet, age, lifestyle and xenobiotic exposure, it has been proposed as a useful tool for the identification of specific pathological conditions by assessing their influence on phenotype. The concentration of OAs in urine may vary in different populations due to different interactions among genetic and phenotypic factors ( 14 ). OAs have been widely used to screen inborn errors of metabolism, where the alterations in metabolite levels may be a hundred-or a thousand-fold increased in comparison to those of healthy subjects and this is reflected on the precision of reference values (RVs) currently used in laboratories ( 14 , 15 ).…”