oxalates and Diabetes-Mellitus

Despite guidelines, routine 24-hour urine testing is completed in <10% of high-risk, recurrent stone formers. Using surrogates for metabolic testing, such as key patient characteristics, could obviate the cost and burden of this test while providing information needed for proper stone prevention counseling.. We performed a retrospective study of 392 consecutive patients from 2007 to 2014 with ≥2 lifetime stone episodes, >70% calcium oxalate by mineral analysis, and ≥1 24-hour urine collection. We compared mean 24-hour urine values by age in decades. We used logistic regression and receiver operating characteristic (ROC) curve analysis to assess the predictive ability of age, gender, body mass index (BMI), and comorbidities to detect abnormal 24-hour urine parameters.. The mean age of the cohort was 51 ± 16 years. Older age was associated with greater urinary oxalate (p-trend <0.001), lower urinary uric acid (UA) (p-trend = 0.007), and lower urinary pH (p-trend <0.001). A nonlinear association was noted between age and urinary calcium or citrate (calcium peaked at 40-49 years, p = 0.03; citrate nadired at 18-29 years, p = 0.001). ROC analysis of age, gender, and BMI to predict 24-hour urine abnormalities performed the best for hyperuricosuria (area under the curve [AUC] 0.816), hyperoxaluria (AUC 0.737), and hypocitraturia (AUC 0.740). Including diabetes mellitus or hypertension did not improve AUC significantly.. In our recurrent calcium oxalate cohort, age significantly impacted urinary calcium, oxalate, citrate, and pH. Along with gender and BMI, age can be used to predict key 24-hour urine stone risk results. These data lay the foundation for a risk prediction tool, which could be a surrogate for 24-hour urine results in recurrent stone formers, who are unwilling or unable to complete metabolic testing. Further validation of these findings is needed in other stone populations.

Topics: Adolescent; Adult; Age Factors; Aged; Body Mass Index; Calcium; Calcium Oxalate; Calcium Phosphates; Citrates; Citric Acid; Comorbidity; Diabetes Mellitus; Female; Humans; Hypercalciuria; Hyperoxaluria; Hypertension; Kidney Calculi; Male; Middle Aged; Nephrolithiasis; Obesity; Oxalates; Recurrence; Regression Analysis; Retrospective Studies; Sex Factors; Uric Acid; Urinalysis; Young Adult

Blood glucose concentrations are essential in defining diabetes mellitus. Recent guidelines advocate either of two discrete methods for sample collection and processing. One of these involves addition of glycolysis inhibitors, such as sodium fluoride-potassium oxalate (NaF-KOx) to sample collection tubes, whereas the other requires immediate refrigeration and sample separation.. To examine whether the choice of the preanalytical process has any impact on subsequent glucose determinations.. 62 healthy men participated in the study during screening for diabetes. Paired venous blood samples were collected in a serum-gel tube and a tube containing NaF-KOx (both Sarstedt, Leicester, UK). Serum was promptly separated from gel tube samples and refrigerated, whereas NaF-KOx samples were not separated until immediately before analysis. Glucose concentrations were determined using an Olympus AU 2700 analyser incorporating an automated hexokinase method.. Mean (95% CI) glucose concentration in serum-gel tube samples was 5.2 mmol/l (5.0 to 5.4 mmol/l), whereas the concentration in tubes containing NaF-KOx was 4.9 mmol/l (4.8 to 5.1 mmol/l). A negative bias of 0.23 mmol/l (0.16 to 0.30 mmol/l) and relative negative bias of 4.7 % (3.2% to 6.3%) were observed for samples collected in NaF-KOx tubes, consistent with the combined effects of glycolysis and dilution.. Bias associated with the use of NaF-KOx tubes may have a significant impact on the prevalence of fasting hyperglycaemia, according to current diagnostic criteria. The small but significant difference between preanalytical processes should be considered when screening for the presence of diabetes mellitus.

Topics: Adolescent; Adult; Bias; Blood Glucose; Blood Specimen Collection; Diabetes Mellitus; Glycolysis; Humans; Male; Mass Screening; Middle Aged; Oxalates; Prevalence; Sodium Fluoride

Greater body mass index (BMI) is a risk factor for kidney stones. However, the relation between BMI and the urinary excretion of many lithogenic factors remains unclear.. We studied urine pH, urine volume, and 24-hour urinary excretion of calcium, oxalate, citrate, uric acid, sodium, magnesium, potassium, phosphate, and creatinine in stone-forming and non-stone-forming participants in the Health Professionals Follow-Up Study (599 stone-forming and 404 non-stone-forming men), Nurses' Health Study (888 stone-forming and 398 non-stone-forming older women), and Nurses' Health Study II (689 stone-forming and 295 non-stone-forming younger women). Each cohort was divided into quintiles of BMI. Tests of linear trend were conducted by 1-way analysis of variance. Linear regression models were adjusted for age, history of stone disease, dietary intake, and urinary factors.. Participants with greater BMIs excreted more urinary oxalate (P for trend

Topics: Adult; Body Mass Index; Calcium; Calcium Oxalate; Citrates; Comorbidity; Creatinine; Diabetes Mellitus; Female; Humans; Hydrogen-Ion Concentration; Hypertension; Kidney Calculi; Linear Models; Magnesium; Middle Aged; Obesity; Oxalates; Phosphates; Potassium; Risk Factors; Sodium; Urine

We evaluated a colorimetric assay for glycosylated hemoglobin to determine the effects of several variables --oxalic acid concentration, extraneous glucose, hemoglobin concentration, hydrolysis interval, and 5-hydroxymethylfurfural destruction--and the precision. The interference seen when the blood glucose concentration exceeds 2.0 g/L (11 mmol/L) can be eliminated by washing the erythrocytes with 9 g/L saline. The accuracy of this assay is not influenced by hemoglobin concentrations from 80 to 150 g/L. The background nonspecific color, although substantial, is similar from sample to sample. After a 5-h hydrolysis at 100 degrees C, about 85% of the hexose is released, and the analytical recovery of 5-hydroxymethylfurfural is constant over a wide range of glycosylated hemoglobin concentrations. The 5th to 95th percentile reference interval for a population of 65 nondiabetic individuals was 4.6 to 6.1 mol per 100 mol of total hemoglobin. The range of values for a population of 85 diabetic patients was 6.9 to 20.4 mol per 100 mol.

Topics: Blood Glucose; Colorimetry; Diabetes Mellitus; Erythrocytes; Evaluation Studies as Topic; Furaldehyde; Glycated Hemoglobin; Humans; Hydrolysis; Oxalates; Time Factors

Topics: Colorimetry; Diabetes Mellitus; Humans; Indicators and Reagents; Oxalates; Reference Values

A new colorimetric method, based on the phenol sulphuric acid reaction of carbohydrates, is described for the determination of glycosylated hemoglobin. Hemolyzates were treated with 1 mol/l oxalic acid in 2 mol/l Hcl for 4 h at 100 degrees C, the protein was precipitated with trichloroacetic acid, and the free sugars and hydroxymethyl furfural in the protein free supernatant were treated with phenol and sulphuric acid to form the color. The new method is compared to the thiobarbituric acid method and the ion-exchange chromatographic method for the estimation of glycosylated hemoglobin in normals and diabetics. The increase in glycosylated hemoglobin in diabetic patients as estimated by the phenol-sulphuric acid method was more significant (P less than 0.001) than the increase observed by the thiobarbituric acid method (P less than 0.01). The correlation between the phenol-sulphuric acid method and the column method was better (r = 0.91) than the correlation between the thiobarbituric acid method and the column method (r = 0.84). No significant correlation between fasting and postprandial blood sugar level and glycosylated hemoglobin level as determined by the two colorimetric methods was observed in diabetic patients.

Topics: Colorimetry; Diabetes Mellitus; Glycosides; Hemoglobin A; Humans; Hydrochloric Acid; Oxalates; Phenols; Sulfuric Acids; Thiobarbiturates

Topics: Alcohol Oxidoreductases; Animals; Cattle; Chromatography, Ion Exchange; Diabetes Mellitus; Glycolates; Lactates; Liver; Male; Oxalates; Rats; Species Specificity; Streptozocin; Time Factors

Topics: Animals; Ascorbic Acid; Chickens; Diabetes Mellitus; False Positive Reactions; Female; Fetal Death; Fetus; Glycosuria; Guinea Pigs; Humans; Oxalates; Phosphates; Pregnancy; Rats; Urinary Calculi

Topics: Ascorbic Acid; Aspirin; Asthma; Calcium; Citrates; Coronary Disease; Depression, Chemical; Diabetes Mellitus; Duodenal Ulcer; Dwarfism, Pituitary; Emphysema; Facial Paralysis; Gluconates; Histamine H1 Antagonists; Humans; Hypertension; Hyperthyroidism; Kidney Calculi; Liver Diseases, Parasitic; Magnesium; Oxalates; Phosphates; Pyridoxine; Schistosomiasis; Stimulation, Chemical; Terpenes; Tuberculosis, Pulmonary

Topics: Chromatography; Diabetes Mellitus; Glucose Tolerance Test; Glycosuria; Oxalates; Pharmacology; Rats; Research; Toxicology; Urine; Xanthurenates