Mean 24-hour Urinary Excretion Research Articles

Human metabolic phenotype diversity and its association with diet and blood pressure.

Metabolic phenotypes are the products of interactions among a variety of factors-dietary, other lifestyle/environmental, gut microbial and genetic. We use a large-scale exploratory analytical approach to investigate metabolic phenotype variation across and within four human populations, based on 1H NMR spectroscopy. Metabolites discriminating across populations are then linked to data for individuals on blood pressure, a major risk factor for coronary heart disease and stroke (leading causes of mortality worldwide). We analyse spectra from two 24-hour urine specimens for each of 4,630 participants from the INTERMAP epidemiological study, involving 17 population samples aged 40-59 in China, Japan, UK and USA. We show that urinary metabolite excretion patterns for East Asian and western population samples, with contrasting diets, diet-related major risk factors, and coronary heart disease/stroke rates, are significantly differentiated (P < 10(-16)), as are Chinese/Japanese metabolic phenotypes, and subgroups with differences in dietary vegetable/animal protein and blood pressure. Among discriminatory metabolites, we quantify four and show association (P < 0.05 to P < 0.0001) of mean 24-hour urinary formate excretion with blood pressure in multiple regression analyses for individuals. Mean 24-hour urinary excretion of alanine (direct) and hippurate (inverse), reflecting diet and gut microbial activities, are also associated with blood pressure of individuals. Metabolic phenotyping applied to high-quality epidemiological data offers the potential to develop an area of aetiopathogenetic knowledge involving discovery of novel biomarkers related to cardiovascular disease risk.

Low platelet-poor plasma concentrations of serotonin in patients with combat-related posttraumatic stress disorder

Background: Combat-related posttraumatic stress disorder (CR-PTSD) is associated with a dysregulation of various neurotransmitter systems. Methods: We assessed levels of platelet-poor plasma (PPP) norepinephrine (NE), and serotonin (5-HT), and 24-hour urinary excretion of NE, dopamine (DA), and homovanillic acid (HVA) in 17 male outpatients with untreated chronic CR-PTSD (age, 33.1 ± 7.4 years) and 10 normal control subjects (age, 35.8 ± 2.7 years). Results: Compared with the control subjects, the PTSD patients showed significantly lower PPP 5-HT levels, elevated PPP NE levels, and significantly higher mean 24-hour urinary excretion of all three catecholamines (NE, DA, and HVA). The 24-hour urinary HVA values of the CR-PTSD patients correlated significantly and positively with the total Impact of Event Scale scores and the avoidance symptoms cluster scores, and the PPP 5-HT levels correlated negatively with the Hamilton Anxiety Rating Scale scores. The PPP NE/5-HT ratio was significantly higher in the study group than in the control subjects. Conclusions: We believe this combined enhanced noradrenergic activity and diminished 5-HT activity may be relevant to the neurobiology of CR-PTSD.

Blastocystis hominis Infection and Intestinal Injury

Blastocystis hominis is an enteric protozoan associated with clinical illness. To determine the prevalence of intestinal injury in patients with B. hominis infection, the authors prospectively evaluated 18 patients with B. hominis infection by endoscopy and a test of intestinal permeability. Seventeen patients had gastrointestinal symptoms. Colonic mucosa appeared normal by lower endoscopy in 12 of 13 patients, and was friable slightly in 1. Duodenal mucosa was normal by upper endoscopy in nine patients. Pathologic examination of mucosal biopsy specimens did not demonstrate evidence of mucosal invasion. 51Cr-edetic acid (51Cr-EDTA) was given to the 18 patients with stools positive for B. hominis and to 32 healthy control subjects. Approximately 100 uCi of 51Cr-EDTA was given orally after an overnight fast, and urine was collected for the following 24 hours. Mean 24-hour urinary excretion of 51Cr-EDTA, calculated as a percent of the administered dose, was 1.31% (0.34-2.76%) in patients with B. hominis infection and 1.99% (0.59-3.48%) in the control subjects. The intestinal permeability to 51Cr-EDTA in blastocystis-infected individuals was not increased, but was decreased significantly compared with healthy subjects (p < 0.005). Therefore, in a group of symptomatic patients with B. hominis infection, endoscopy typically did not show evidence of significant intestinal inflammation, and results of intestinal permeability testing with 51Cr-EDTA did not suggest impaired barrier function of the intestinal mucosa. The clinical literature on B. hominis infection and intestinal injury is reviewed.

Decreased renal phosphate threshold in patients with gout.

Serum and 24-hour urinary phosphate levels in primary gout patients and control subjects were measured. About 45% of gouty patients showed mild hypophosphatemia. However, mean 24-hour urinary excretion of phosphate was significantly elevated as compared with that of controls. Gouty patients showed a significantly decreased tubular reabsorption of phosphate and renal phosphate threshold. It seems that tubular phosphate transport in gouty patients is impaired, and this is the major cause of hypophosphatemia.

Evaluation of urine and serum metabolites in Miniature Schnauzers with calcium oxalate urolithiasis

SUMMARY To evaluate underlying causes of calcium oxalate urolithiasis, 24-hour excretion of urine metabolites was measured in 6 Miniature Schnauzers that formed calcium oxalate (CaOx) uroliths during periods when they were fed a standard diet and during periods when food was withheld. Serum concentrations of parathyroid hormone and 1,25-dihydroxyvitamin D also were evaluated. Serum calcium concentrations were normal in all 6 affected Miniature Schnauzers; however, during diet consumption, mean 24-hour urinary excretion of calcium was significantly (P = 0.025) higher than calcium excretion when food was withheld. In 1 dog, urinary calcium excretion was lower during the period of food consumption, compared with the period when food was withheld. Compared with clinically normal Beagles, Miniature Schnauzers that formed CaOx uroliths excreted significantly greater quantities of calcium when food was consumed (P = 0.0004) and when food was withheld (P = 0.001). Miniature Schnauzers that formed CaOx uroliths excreted significantly less oxalate than clinically normal Beagles during fed (P = 0.028) and nonfed (P = 0.004) conditions. Affected Miniature Schnauzers also excreted abnormally high quantities of uric acid. Excretion of citrate was not different between Miniature Schnauzers with CaOx urolithiasis and clinically normal Beagles. In 5 of 6 Miniature Schnauzers with CaOx urolithiasis, concentrations of serum parathyroid hormone were similar to values from age- and gender-matched Miniature Schnauzers without uroliths. The concentration of serum parathyroid hormone in 1 dog was &gt; 4 times the mean concentration of clinically normal Miniature Schnauzers. Mean serum concentrations of 1,25-dihydroxyvitamin D in Miniature Schnauzers with calcium oxalate urolithiasis were similar to concentrations of clinically normal Miniature Schnauzers.

Calcium and Phosphorus Metabolism in Nephrotic Syndrome

Calcium and phosphorus balance studies were performed on 13 nephrotic patients and eight patients during clinical remission of the nephrotic syndrome. Marked impairment of intestinal absorption of calcium was found among nephrotic patients, in eight of whom faecal calcium equalled or exceeded dietary calcium. The mean faecal:dietary calcium ratio of nephrotic patients, 1-06 +/- 0-23 (SD), was significantly higher (p less than 0-005) than that of patients in remission, 0-58 +/- 0-21 (SD). The mean 24-hour urinary excretion of calcium of nephrotic patients, 0-68 +/- 0-68 (SD) mmol, was significantly lower (p less than 0-005) than that of patients in remission, 3-02 +/- 1-91 (SD) mmol. Calciferol administered to three nephrotic patients in the dosage of 1.25 mg per day did not significantly influence intestinal absorption or renal excretion of calcium. There was no difference between the two groups of patients in intestinal absorption or renal excretion of phosphorus; there was net intestinal absorption in all subjects. Quantitative bone histology was studied in seven of the nephrotic patients. None had osteomalacia or osteitis fibrosa, while only one had evidence of mild osteoporosis.

Altered copper and zinc metabolism in primary hyperparathyroidism.

Mean 24-hour urinary excretion of copper and zinc was greater than normal in 17 patients with untreated primary hyperparathyroidism. Mean total serum copper concentration in these patients was slightly greater than the normal mean, whereas mean total zinc concentration was normal. After surgical treatment of hyperparathyroidism there was a transient further increase in urinary copper and zinc concentrations in the 13 patients so studied, with no consistent change in serum copper or zinc concentrations. Five patients were studied for several days after this postoperative peak had passed. Urinary copper and zinc excretion decreased in three in relation to surgical correction of their hyperparthyroidism and remained elevated in one with persistent hypercalcemia. In the fifth patient urinary zinc excretion increased to slightly above the normal range despite successful surgery. These results suggest that changes in urinary excretion of copper and zinc may be useful indicators in the diagnosis and treatment of patients with primary hyperparathyroidism.

Catecholamines and indoleamines in patients with Duchenne muscular dystrophy.

Several studies have raised the question of abnormal biogenic amine metabolism in Duchenne muscular dystrophy (DMD). A small group of DMD patients and controls were screened for abnormalities in systemic biogenic amine metabolism in a carefully controlled clinical environment The mean 24-hour urinary excretion levels of norepinephrine, epinephrine, and 5-hydroxyindoleacetic acid (5-HIAA) were identical in the group of DMD patients compared to their normal sibling controls. In the cerebrospinal fluid (CSF), 5-HIAA and homovanillic acid (HVA) levels were similar in DMD patients and controls, and no 5-hydroxytryptamine (5-HT) was detected in the CSF of either group. This study suggests that the characteristic lesions of DMD do not result from a simple excess of circulating amines.