scholarly journals Net Acid Excretion and Urinary Organic Anions in Idiopathic Uric Acid Nephrolithiasis

2019 ◽  
Vol 14 (3) ◽  
pp. 411-420 ◽  
Author(s):  
I. Alexandru Bobulescu ◽  
Sun K. Park ◽  
L.H. Richie Xu ◽  
Francisco Blanco ◽  
John Poindexter ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Uric Acid ◽  
Organic Acids ◽  
Body Mass ◽  
Organic Anions ◽  
Acid Excretion ◽  
Urine Ph ◽  
Control Subjects ◽  
Uric Acid Nephrolithiasis ◽  
Net Acid Excretion

Background and objectivesIdiopathic uric acid nephrolithiasis, which is closely associated with obesity and the metabolic syndrome, is increasing in prevalence. Unduly acidic urine pH, the quintessential pathophysiologic feature of this disease, is in part explained by inadequate excretion of the principal urinary buffer ammonium. The role of net acid excretion in the pathogenesis of uric acid nephrolithiasis is incompletely understood.Design, setting, participants, & measurementsWe compared acid-base parameters of patients with idiopathic uric acid nephrolithiasis with matched control subjects under controlled diets in an inpatient metabolic unit. Measurements included fasting blood and 24-hour urine chemistries and 24-hour urine metabolomic analysis. Comparisons between groups included analysis of covariance models controlling for urine pH or body mass index.ResultsSubjects with idiopathic uric acid nephrolithiasis had lower urine pH (5.5 versus 5.9; P<0.001) and higher net acid excretion (60 versus 43 mEq/24 h; P<0.001), with the excess H+ carried by nonammonium buffers. In all subjects, there was a positive relationship of net acid excretion with higher body mass index in spite of strictly controlled equivalent dietary acid intake. This relationship was most evident among control subjects (r=0.36; P=0.03). It was attenuated in patients with idiopathic uric acid nephrolithiasis whose net acid excretion remained fixedly high and ammonium excretion remained low relative to net acid excretion, resulting in low urine pH over a wide body mass index range. Urinary metabolomics was performed to attempt to identify excess organic acids presented to the kidney in idiopathic uric acid nephrolithiasis. Among the tricarboxylic acid cycle intermediates and amino acid and lipid metabolites analyzed, 26 organic anions with acid dissociation constants values in the range of urine pH showed greater protonation. However, protons carried by the identified organic acids did not entirely account for the higher titratable acidity seen in idiopathic uric acid nephrolithiasis.ConclusionsHigher acid load to the kidney, resulting in higher urinary net acid excretion, is an important factor in the pathogenesis of idiopathic uric acid nephrolithiasis.

Role of organic anions in renal response to dietary acid and base loads

1989 ◽  
Vol 257 (2) ◽  
pp. F170-F176 ◽  
Author(s):  
J. C. Brown ◽  
R. K. Packer ◽  
M. A. Knepper
Keyword(s):  
Organic Anion ◽  
Organic Anions ◽  
Acid Excretion ◽  
Acid Base Balance ◽  
Acid Base ◽  
Urine Ph ◽  
Renal Response ◽  
Base Balance ◽  
Net Acid Excretion

Bicarbonate is formed when organic anions are oxidized systemically. Therefore, changes in organic anion excretion can affect systemic acid-base balance. To assess the role of organic anions in urinary acid-base excretion, we measured urinary excretion in control rats, NaHCO3-loaded rats, and NH4Cl-loaded rats. Total organic anions were measured by the titration method of Van Slyke. As expected, NaHCO3 loading increased urine pH and decreased net acid excretion (NH4+ + titratable acid - HCO3-), whereas NH4Cl loading had the opposite effect. Organic anion excretion was increased in response to NaHCO3 loading and decreased in response to NH4Cl loading. We quantified the overall effect of organic ion plus inorganic buffer ion excretion on acid-base balance. The amounts of organic anions excreted by all animals in this study were greater than the amounts of NH4+, HCO3-, or titratable acidity excreted. In addition, in response to acid and alkali loading, changes in urinary organic anion excretion were 40-50% as large as changes in net acid excretion. We conclude that, in rats, regulation of organic anion excretion can contribute importantly to the overall renal response to acid-base disturbances.

scholarly journals Association of Urine Findings with Metabolic Syndrome Traits in a Population of Patients with Nephrolithiasis

2021 ◽  
Author(s):  
Virginia L Hood ◽  
Kevan M Sternberg ◽  
Desiree de Waal ◽  
John R Asplin ◽  
Carley Mulligan ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Uric Acid ◽  
Calcium Oxalate ◽  
Protein Intake ◽  
Dietary Factors ◽  
Acid Excretion ◽  
Urine Ph ◽  
Stone Composition ◽  
Calcium Oxalate Stones ◽  
Net Acid Excretion

Background and objectives: The odds of nephrolithiasis increase with more metabolic syndrome (met-s) traits. We evaluated associations of metabolic and dietary factors from urine studies and stone composition with met-s traits in a large cohort of stone-forming patients. Design, setting, participants & measurements: Patients >18 years, who were evaluated for stones with 24 h urine collections, July 2009-December 2018, had records reviewed retrospectively. Patient factors, laboratory values and diagnoses were identified within 6 months of urine collection and stone composition within 1 year. Four groups with 0, 1, 2, > 3 met-s traits (hypertension, obesity, dyslipidemia, diabetes) were evaluated. Trends across groups were tested using linear contrasts in analysis of variance and analysis of covariance. Results: 1473 patients met inclusion criteria (835 with stone composition). Met-s groups were 0=684, 1=425, 2=211, 3 and 4 =153. There were no differences among groups for urine volume, calcium or ammonium (NH4) excretion. There was a significant trend (p<0.001) for more met-s traits being associated with decreasing urine pH, increasing age, calculated dietary protein, urine uric acid, oxalate, citrate, titratable acid (TAP), net acid excretion (eNAE) and uric acid supersaturation. The ratio of ammonium to net acid excretion did not differ among the groups. After adjustment for protein intake, the fall in urine pH remained strong, while the upward trend in TAP excretion was attenuated and NH4 decreased. Calcium oxalate stones were most common, but there was a trend for more uric acid (p<0.001) and fewer calcium phosphate (p=0.09) and calcium oxalate stones (p=0.01) with more met-s traits. Conclusions: Stone forming patients with met-s have a defined pattern of metabolic and dietary risk factors that contribute to an increased risk of stone formation including higher acid excretion, largely the result of higher protein intake, and lower urine pH.

scholarly journals Association of Urine Findings with Metabolic Syndrome Traits in a Population of Patients with Nephrolithiasis

Kidney360 ◽  
2021 ◽  
pp. 10.34067/KID.0002292021
Author(s):  
Virginia L. Hood ◽  
Kevan M. Sternberg ◽  
Desiree de Waal ◽  
John R. Asplin ◽  
Carley Mulligan ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Uric Acid ◽  
Calcium Oxalate ◽  
Protein Intake ◽  
Dietary Factors ◽  
Acid Excretion ◽  
Urine Ph ◽  
Stone Composition ◽  
Calcium Oxalate Stones ◽  
Net Acid Excretion

Background: The odds of nephrolithiasis increase with more metabolic syndrome (met-s) traits. We evaluated associations of metabolic and dietary factors from urine studies and stone composition with met-s traits in a large cohort of stone-forming patients. Methods: Patients >18 years, who were evaluated for stones with 24 h urine collections, July 2009-December 2018, had records reviewed retrospectively. Patient factors, laboratory values and diagnoses were identified within 6 months of urine collection and stone composition within 1 year. Four groups with 0, 1, 2, > 3 met-s traits (hypertension, obesity, dyslipidemia, diabetes) were evaluated. Trends across groups were tested using linear contrasts in analysis of variance and analysis of covariance. Results: 1473 patients met inclusion criteria (835 with stone composition). Met-s groups were 0=684, 1=425, 2=211, 3 and 4 =153. There were no differences among groups for urine volume, calcium or ammonium excretion. There was a significant trend (p<0.001) for more met-s traits being associated with decreasing urine pH, increasing age, calculated dietary protein, urine uric acid, oxalate, citrate, titratable acid phosphate, net acid excretion and uric acid supersaturation. The ratio of ammonium to net acid excretion did not differ among the groups. After adjustment for protein intake, the fall in urine pH remained strong, while the upward trend in acid excretion was lost. Calcium oxalate stones were most common, but there was a trend for more uric acid (p<0.001) and fewer calcium phosphate (p=0.09) and calcium oxalate stones (p=0.01) with more met-s traits. Conclusions: Stone forming patients with met-s have a defined pattern of metabolic and dietary risk factors that contribute to an increased risk of stone formation including higher acid excretion, largely the result of greater protein intake, and lower urine pH.

scholarly journals Serum Periostin as a Potential Biomarker in Pediatric Patients with Primary Hypertension

2021 ◽  
Vol 10 (10) ◽  
pp. 2138
Author(s):  
Michał Szyszka ◽  
Piotr Skrzypczyk ◽  
Anna Stelmaszczyk-Emmel ◽  
Małgorzata Pańczyk-Tomaszewska
Keyword(s):  
Blood Pressure ◽  
Body Mass Index ◽  
Uric Acid ◽  
Body Mass ◽  
Pediatric Patients ◽  
Univariate Analysis ◽  
Primary Hypertension ◽  
Potential Biomarker ◽  
Arterial Damage ◽  
Serum Periostin

Experimental studies suggest that periostin is involved in tissue repair and remodeling. The study aimed to evaluate serum periostin concentration as potential biomarker in pediatric patients with primary hypertension (PH). We measured serum periostin, blood pressure, arterial damage, biochemical, and clinical data in 50 children with PH and 20 age-matched healthy controls. In univariate analysis, children with PH had significantly lower serum periostin compared to healthy peers (35.42 ± 10.43 vs. 42.16 ± 12.82 [ng/mL], p = 0.038). In the entire group of 70 children serum periostin concentration correlated negatively with peripheral, central, and ambulatory blood pressure, as well as with aortic pulse wave velocity (aPWV). In multivariate analysis, periostin level significantly correlated with age (β = −0.614, [95% confidence interval (CI), −0.831–−0.398]), uric acid (β = 0.328, [95%CI, 0.124–0.533]), body mass index (BMI) Z-score (β = −0.293, [95%CI, −0.492–−0.095]), high-density lipoprotein (HDL)-cholesterol (β = 0.235, [95%CI, 0.054–0.416]), and triglycerides (β = −0.198, [95%CI, −0.394–−0.002]). Neither the presence of hypertension nor blood pressure and aPWV influenced periostin level. To conclude, the role of serum periostin as a biomarker of elevated blood pressure and arterial damage in pediatric patients with primary hypertension is yet to be unmasked. Age, body mass index, uric acid, and lipid concentrations are key factors influencing periostin level in pediatric patients.

Decreased Bone Density in Adolescent Girls With Anorexia Nervosa

PEDIATRICS ◽  
1990 ◽  
Vol 86 (3) ◽  
pp. 440-447 ◽  
Author(s):  
Laura K. Bachrach ◽  
David Guido ◽  
Debra Katzman ◽  
Iris F. Litt ◽  
Robert Marcus
Keyword(s):  
Bone Mineral Density ◽  
Body Mass Index ◽  
Anorexia Nervosa ◽  
Bone Density ◽  
Bone Mass ◽  
Body Mass ◽  
Bone Mineral ◽  
Whole Body ◽  
Mineral Density ◽  
Control Subjects

Osteoporosis develops in women with chronic anorexia nervosa. To determine whether bone mass is reduced in younger patients as well, bone density was studied in a group of adolescent patients with anorexia nervosa. With single- and dual-photon absorptiometry, a comparison was made of bone mineral density of midradius, lumbar spine, and whole body in 18 girls (12 to 20 years of age) with anorexia nervosa and 25 healthy control subjects of comparable age. Patients had significantly lower lumbar vertebral bone density than did control subjects (0.830 ± 0.140 vs 1.054 ± 0.139 g/cm2) and significantly lower whole body bone mass (0.700 ± 0.130 vs 0.955 ± 0.130 g/cm2). Midradius bone density was not significantly reduced. Of 18 patients, 12 had bone density greater than 2 standard deviations less than normal values for age. The diagnosis of anorexia nervosa had been made less than 1 year earlier for half of these girls. Body mass index correlated significantly with bone mass in girls who were not anorexic (P &lt; .05, .005, and .0001 for lumbar, radius, and whole body, respectively). Bone mineral correlated significantly with body mass index in patients with anorexia nervosa as well. In addition, age at onset and duration of anorexia nervosa, but not calcium intake, activity level, or duration of amenorrhea correlated significantly with bone mineral density. It was concluded that important deficits of bone mass occur as a frequent and often early complication of anorexia nervosa in adolescence. Whole body is considerably more sensitive than midradius bone density as a measure of cortical bone loss in this illness. Low body mass index is an important predictor of this reduction in bone mass.

scholarly journals Serum uric acid as a predictor of future hypertension: Stratified analysis based on body mass index and age

2016 ◽  
Vol 90 ◽  
pp. 201-206 ◽  
Author(s):  
Yuki Yokoi ◽  
Takahisa Kondo ◽  
Naoki Okumura ◽  
Keiko Shimokata ◽  
Shigeki Osugi ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Uric Acid ◽  
Serum Uric Acid ◽  
Body Mass ◽  
Stratified Analysis

Abstract 3147: Uric Acid Independently Predicted Acute Coronary Syndrome in a Large Cohort of Ethnic Chinese

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Shao-Yuan Chuang ◽  
Jonathan Jiunn-Horng Chen ◽  
Chih-Cheng Wu ◽  
Wen-Harn Pan
Keyword(s):  
Body Mass Index ◽  
Acute Coronary Syndrome ◽  
Uric Acid ◽  
Total Cholesterol ◽  
Body Mass ◽  
Ethnic Chinese ◽  
Coronary Syndrome ◽  
Group 4 ◽  
Group 3 ◽  
Group 2

Few studies examine the association between serum uric acid (SUA) and acute coronary syndrome (ACS). We aimed to investigate the association between SUA and ACS in a prospective study of ethnic Chinese. Enrolled were 128569 adults ≥ 20 yrs from 4 MJ Health Checkup Clinics in Taiwan during 1994 –1996, excluding those with heart disease, stroke, renal disease and cancer disease. All physical examination, biochemical test and structured questionnaire were executed in standardized central labs. ACS was defined by main ICD-9 of 410 – 414 from claim data of National Health Insurance for hospitalization and from Death certification registry. Cox proportional hazard model was used to estimate the hazard ratios (HRs) between levels of SUA and ACS events. A total of 2049 subjects (Men: 1239/Women: 810) developed ACS during the period from baseline to Dec.31.2002. Men had higher ACS incidence than women (2.84 vs. 1.61 per 1000 person-years [PY]; p < .0001). Independent risk factors of ACS unfolded from this study included age, male sex, waist circumference, body mass index, triglycerides, total-cholesterol, hypertension, diabetes, uric acid, and current smoking. The crude incidences of ACS were 1.27, 2.06, 3.27 and 4.61 per 1000 PY in that order for four consecutive SUA groups (group1: <5.0 mg/dl; group 2: 5.0 – 6.9 mg/dl; group 3: 7.0 – 8.9 mg/dl; group 4: ≥9.0 mg/dl) (p-value for trend <.0001). Compared to group1, the multi-variate adjusted HRs (95% Confidence intervals) were 1.14 (0.92, 1.42) for group 2, 1.38 (1.10, 1.72) for group 3 and 1.38 (1.10, 1.72) for group 4 among men, and 1.03 (0.87, 1.22), 1.30 (1.05, 1.62) and 1.43 (0.99, 2.05) among women after adjusting for age, systolic/diastolic BP, body mass index, triglycerides, total cholesterol, diabetes, smoking, alcohol drinking, physical activity, and occupation. One standard deviation increase in SUA corresponded to around 30% ACS risk increase in women (HR=1.33; 1.04 –1.70) and 60% in men (HR=1.59; 1.25–2.03). Baseline SUA level independently predicts the development of ACS and should be considered as a potential risk factor of ACS.

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