Sodium and potassium intake was assessed on the basis of its respective excretion levels in 24 hr urine samples. However, owing to the inconvenience of collection, we evaluated random spot urine for alternative sodium and potassium excretion markers. We included 250 patients who submitted 24 hr- and spot urine for clinical tests. However, 22 patients who showed 24 hr urine creatinine excretion levels <500 mg/day were excluded, because these samples possibly resulted from incomplete urine collection. Moreover, 24 patients were excluded because of their use of diuretics during the urine collection period. We observed significant correlations between 24 hr urine sodium excretion and both the sodium/creatinine (r=0.34, P<0.0001) and the sodium/specific gravity unit (SGU) ratios (r=0.19, P=0.007) in random urine samples. Similarly, 24 hr urine potassium excretion and both the spot urine potassium/creatinine (r=0.47, P<0.0001) and potassium/SGU ratios (r=0.28, P<0.0001) were significantly correlated. Although the estimated sodium/creatinine and potassium/creatinine ratios showed a significant correlation with 24 hr urine sodium and potassium excretion, respectively, further studies are required to develop a spot urine test for individualized monitoring of sodium and potassium excretion.
Biomarkers/urine ; Creatinine/*urine ; Humans ; Hypertension/pathology/urine ; Potassium/*urine ; Sodium/*urine ; Urinalysis ; Urine Specimen Collection

Colorimetry ; methods ; Humans ; Manganese ; urine ; Potassium Permanganate

BACKGROUND: Estimates of daily sodium (Na) and potassium (K) excretion were explicitly biased when using equations for adults. We aimed to develop equations to estimate them using overnight urine from Japanese children and adolescents. METHODS: The subjects comprised 70 students aged 10.49-15.76 years: validation group, n = 34; and verification group, n = 36. Each subject performed two operations of overnight spot urine (U RESULTS: In validation, we formulated Na excretion (mg d CONCLUSION We obtained validated equations to estimate daily Na and K excretion with accessible variables such as Na, K, and Cr concentrations of overnight urine, body height and weight, and age for children and adolescents. When using the obtained equations, caution should be paid to small but definite biases and measurement errors.
Adolescent ; Child ; Creatinine/urine* ; Female ; Humans ; Japan ; Male ; Potassium/urine* ; Sodium/urine*

OBJECTIVE: To explore the objective evidence of the corpus biochemical changes in rabbits for postmortem diagnosis of potassium intoxication. METHODS: Rabbits were sacrificed by Infusion of 0.3% KCl at full speed push or 1% KCl at 100 drip/min, respectively, with normal rabbits used as control. Cardiac blood and urine samples were collected before and after potassium infusion to examine the concentrations of various electrolytes (K+, Na+, Ca2+, Mg2+, Cl-, and HCO3-) and to observe the antemortem and postmortem biochemical changes. RESULTS: The mean lethal infusion time in the 0.3%KCl group was longer than that in the 1% KCl group (P = 0.006). The serum concentration of K+ increased while the serum concentrations of Na+, Ca2+, Cl-, and HCO3- decreased after the infusion. There were no statistically significant differences in the whole blood concentration of K+ as well as the serum concentration of Mg2+ between the two groups (P = 0.062). There were statistically significant differences in the concentrations of whole blood K+, as well as serum Na+, Mg2+, and Cl-, but not in the serum K+, Ca2+, and HCO3-. There were no statistically significant differences seen in the urine volumes and the concentrations of all the urine electrolytes between the groups. CONCLUSION Examination of the concentrations of K+ both in the whole blood and serum, as well as Mg2+ in the serum may be helpful for postmortem diagnosis of potassium intoxication.
Animals ; Calcium/urine* ; Electrolytes/urine* ; Forensic Medicine/methods* ; Injections, Intravenous/methods* ; Magnesium/urine* ; Male ; Postmortem Changes ; Potassium/poisoning* ; Potassium Chloride/administration & dosage* ; Rabbits ; Sodium/urine*

Objective: To investigate the associations between 24-hour urinary sodium excretion (24hUNaE) and all-cause mortality in adult Northern Chinese population. Methods: Data from this study were derived from the prospective urban and rural epidemiology (PURE) study in north China. Baseline information of all participants were obtained by face to face interview through trained research staffs based on questionnaires, and morning fasting urine samples of participants were collected to estimate 24hUNaE and 24-hour potassium excretion (24hUKE). Multivariable frailty Cox regression models were used to explore the association between 24hUNaE (<3.00, 3.00-3.99, 4.00-4.99, 5.00-5.99 and ≥6 g/d) and all-cause death. Results: A total of 27 310 participants were included in this study. The mean 24hUNaE was (5.84±1.73) g/d. After a median follow-up of 8.8 years, 1 024 participants died (3.7%), including 390 cardiovascular related deaths and 591 non-cardiovascular related deaths. The cause of death of the remaining patients could not be determined. Using 24hUNaE level of 4.00-4.99 g/d as the reference group, after fully adjustment, 24hUNaE ≥6.00 g/d was associated with an increased risk of all-cause death (HR=1.24, 95%CI: 1.02-1.49) and cardiovascular related death (HR=1.39, 95%CI: 1.02-1.88). 24hUNaE<3.00 g/d was associated with increased risk of all-cause mortality (HR=1.38, 95%CI: 0.96-1.99). There was no significant association between 24hUNaE and non-cardiovascular related death. Furthermore, using the combination of 24hUNaE 4.00-4.99 g/d and 24hUKE≥2.11 g/d as the reference group, the highest risk occurred in participants with the combination of low sodium (<3.00 g/d) and low potassium (<2.11 g/d). Conclusion: 24hUNaE equal or higher than 6 g/d or lower than 3 g/d is associated with increased risk of all-cause mortality and cardiovascular related death in Northern Chinese population. Besides, moderate sodium intake in combination with increased potassium intake might reduce the risk of all-cause death.
Humans ; Adult ; Sodium/urine* ; Prospective Studies ; Potassium/urine* ; China/epidemiology* ; Proportional Hazards Models ; Cardiovascular Diseases/epidemiology*

AIMTo explore the characteristics of the urinary excretion in the elderly patients and to offer some advice for the prevention and treatment of hyponatremia in the elderly patients.

METHODS42 inpatients aged over 80 were divided into tow groups according to their creatinine clearance rate (CCR). Meanwhile, 24 patients aged 45-59 and 31 patients aged 60-79 were chosen as the control groups. All patients were examined 24h urinary electrolytes and CCR.

RESULTS(1) The CCR in the elderly group was lower than in the middle-aged and old group and the 24 h urinary sodium excretion was accordingly diminished than the two groups. 24 h urinary sodium excretion in CCR abnormal group was also diminished than in CCR normal group. The urinary sodium excretion was not linearly correlate with the CCR in middle-aged group and old group but was linearly correlate in the elderly group. (2) The elderly patients' capability of holding blood sodium and excreting potassium was declined in the CCR normal group. But the urinary excretion of sodium, potassium and phosphonium were all diminished in CCR abnormal group. (3) All patients' sodium intake was higher than the criteria made by China Hypertension Association.

CONCLUSIONTheir urinary sodium excretion is linearly correlate with CCR. Urinary sodium excretion is increased when the elderly patients' renal function is relative normal but when the renal function is severely damaged, urinary sodium excretion is diminished.

Age Factors ; Aged ; Aged, 80 and over ; Calcium ; urine ; Coronary Disease ; urine ; Creatinine ; metabolism ; Humans ; Male ; Middle Aged ; Potassium ; urine ; Sodium ; urine

OBJECTIVETo investigate suitable biomarkers for workers exposure to trimethyltin chloride (TMT-cl).

METHODSUrinary samples of 44 male workers from five TMT-cl occupational poisoning incidents were collected. Methyltin mercaptide stabilizers and waste plastics used in the incidents were also collected. The levels of TMT-cl in all the samples were determined by gas chromatography. The concentration of blood potassium for each poisonings was determined compared to control group (50 male workers of a food company), and the correlation between blood potassium and urinary TMT-cl were also determined.

RESULTSTMT-cl was detected in urine of all the poisonings. The results were (0.869 +/- 0.392) microg/L (severe poisoning), (0.963 +/- 0.482) microg/L (moderate poisoning), (0.716 +/- 0.384) microg/L (mild poisoning) respectively and the difference was statistically significant (P < 0.01). But the severity of the clinical status did not seem to be closely correlated to the level of urinary TMT-cl (F = 1.88, P > 0.05). In the severe poisonings, there were no differences in urinary TMT-cl on day 4 after poisoning from day 1 (P > 0.05). In contrast, urinary TMT-cl was decreased significantly on day 4 than on day 1 in mild and moderate poisonings (P < 0.01). On day 21, levels of urinary TMT-cl of all the poisonings were higher than those of the workers exposed to TMT-cl who had no clinical status (P < 0.01). Blood potassium levels of exposed group was 77.3% which was significantly lower than normal value (P < 0.01). The concentration of blood potassium was lower than normal value (3.5 mmol/L) and was correlated with the severity of the clinical status (F = 4.45, P < 0.05). Level of urinary TMT-cl of exposed group was negatively correlated with blood potassium (r = -0.4456, P < 0.01).

CONCLUSIONLevel of urinary TMT-cl can be used as exposure biomarker of TMT-cl poisoning. Blood potassium is an early biomarker of effect for TMT-cl poisoning so as to find poisoning population early.

Adult ; Biomarkers ; blood ; urine ; Humans ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; Potassium ; blood ; Trimethyltin Compounds ; poisoning ; urine ; Young Adult

AIMTo establish a polarographic method of parallel catalytic hydrogen wave for determination of glimepiride.

METHODSThe catalytic wave of glimepiride in the presence of K2S2O8 was used to improve the analytical sensitivity. The rapid determination of glimepiride was done by linear single sweep polarography.

RESULTSThe catalytic hydrogen wave of glimepiride was measured at ca. -1.36 (vs SCE) in 0.09 mol x L(-1) Na2B4O7-KH2PO4 (pH 6.24 +/- 0.1) supporting electrolyte. When 1.0 x 10(-2) mol x L(-1) K2S2O8 was present, the current increased by 25 times, and the peak potentioal was unchanged, producing a more sensitive parallel catalytic hydrogen wave. The peak current of the parallel catalytic hydrogen wave was rectilinear to the glimepiride concentration in the range 1.0 x 10(-7) - 4.2 x 10(-5) mol x L(-1) (r = 0.9990, n = 9). The detection limit was 5.0 x 10(-8) mol x L(-1).

CONCLUSIONThe proposed method could be applied to the determination of glimepiride in pharmaceuticals without preliminary separation.

Catalysis ; Humans ; Hypoglycemic Agents ; analysis ; urine ; Male ; Polarography ; methods ; Potassium Compounds ; analysis ; Sulfates ; analysis ; Sulfonylurea Compounds ; analysis ; urine

BACKGROUND: Refrigeration is the most common method of preservation for 24 hour urine collection. We tried to find out if the concentrations of the frequently measured chemicals in urine refrigerated for 24 hours were different from those in fresh urine. METHODS: The concentration of calcium, phosphorus, uric acid, creatinine, sodium, potassium, chloride, and protein was measured in fresh urine specimens for routine urine analysis. After refrigeration of the rest of the urine specimens for 24 hours, the same tests were performed, and the results of them were compared with those of fresh urine. Some urine specimens showed precipitation and decreased uric acid concentration after precipitation, and the chemical properties of them were determined statistically. RESULTS: The concentrations of the protein, phosphorus, creatinine, sodium, potassium, and chloride of refrigerated urine was not different statistically from those of the fresh one, but calcium and uric acid showed statistical difference between fresh and refrigerated samples (P<0.05). Urine specimens with precipitation and decreased uric acid showed chemical characteristics of high uric acid concentration and low pH. CONCLUSIONS: For the measurements of total protein, phosphorus, creatinine, sodium, potassium, and chloride, the urine can be refrigerated while collection of 24 hours, but additional procedure is recommended for the measurement of calcium and uric acid.
Calcium ; Creatinine ; Hydrogen-Ion Concentration ; Phosphorus ; Potassium ; Refrigeration ; Sodium ; Uric Acid ; Urine Specimen Collection

BACKGROUND: The low accuracy of equations predicting 24-h urinary sodium excretion using a single spot urine sample contributed to the misclassification of individual sodium intake levels. The application of single spot urine sample is limited by a lack of representativity of urinary sodium excretion, possibly due to the circadian rhythm in urinary excretion. This study aimed to explore the circadian rhythm, characteristics, and parameters in a healthy young adult Chinese population as a theoretical foundation for developing new approaches. METHODS: Eighty-five participants (mean age 32.4 years) completed the 24-h urine collection by successively collecting each of the single-voided specimens within 24 h. The concentrations of the urinary sodium, potassium, and creatinine for each voided specimen were measured. Cosinor analysis was applied to explore the circadian rhythm of the urinary sodium, potassium, and creatinine excretion. The excretion per hour was computed for analyzing the change over time with repeated-measures analysis of variance and a cubic spline model. RESULTS: The metabolism of urinary sodium, potassium, and creatinine showed different patterns of circadian rhythm, although the urinary sodium excretion showed non-significant parameters in the cosinor model. A significant circadian rhythm of urinary creatinine excretion was observed, while the circadian rhythm of sodium was less significant than that of potassium. The circadian rhythm of urinary sodium and creatinine excretion showed synchronization to some extent, which had a nocturnal peak and fell to the lowest around noon to afternoon. In contrast, the peak of potassium was observed in the morning and dropped to the lowest point in the evening. The hourly urinary excretion followed a similar circadian rhythm. CONCLUSION It is necessary to consider the circadian rhythm of urinary sodium, potassium, and creatinine excretion in adults while exploring the estimation model for 24-h urinary sodium excretion using spot urine.
Adult ; China ; Circadian Rhythm ; Creatinine ; Humans ; Potassium ; Sodium ; Urine Specimen Collection ; Young Adult