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

It is not well described the pathophysiology of renal injuries caused by a high salt intake in humans. The authors analyzed the relationship between the 24-hr urine sodium-to-creatinine ratio (24HUna/cr) and renal injury parameters such as urine angiotensinogen (uAGT/cr), monocyte chemoattractant peptide-1 (uMCP1/cr), and malondialdehyde-to-creatinine ratio (uMDA/cr) by using the data derived from 226 hypertensive chronic kidney disease patients. At baseline, the 24HUna/cr group or levels had a positive correlation with uAGT/cr and uMDA/cr adjusted for related factors (P<0.001 for each analysis). When we estimated uAGT/cr in the 24HUna/cr groups by ANCOVA, the uAGT/cr in patients with > or =200 mEq/g cr was higher than in patients with <100 mEq/g cr (708 [95% CI, 448-967] vs. 334 [95% CI, 184-483] pg/mg cr, P=0.014). Similarly, uMDA/cr was estimated as 0.17 (95% CI, 0.14-0.21) pM/mg cr in patients with <100 mEq/g cr and 0.27 (95% CI, 0.20-0.33) pM/mg cr in patients with > or =200 mEq/g cr (P=0.016). During the 16-week follow-up period, an increase in urinary sodium excretion predicted an increase in urinary angiotensinogen excretion. In conclusion, high salt intake increases renal renin-angiotensin-system (RAS) activation, primarily, and directly or indirectly affects the production of reactive oxygen species through renal RAS activation.
Adult ; Aged ; Angiotensinogen/urine ; Chemokine CCL2/urine ; Creatine/urine ; Demography ; Female ; Follow-Up Studies ; Humans ; Hypertension/complications ; Male ; Malondialdehyde/urine ; Middle Aged ; Reactive Oxygen Species/*metabolism ; Renal Insufficiency, Chronic/complications/*pathology ; Renin-Angiotensin System/*physiology ; Sodium, Dietary/*urine ; Urine Specimen Collection

We investigated the association between 24-hr urinary sodium (24UNA) and adequacy of blood pressure (BP) control in patients with chronic kidney disease (CKD) and nonCKD. All data were collected retrospectively by accessing the electrical medical records in patients with 24-hr urine collection and serum creatinine. Enrolled 400 subjects were subgrouped by the amount of 24UNA, or CKD stage. The appropriate BP was defined as BP < 130/80 mmHg for subjects with proteinuria, and BP < 140/90 mmHg for subjects without proteinuria. The mean level of 24UNA was 166+/-76 mEq/day. The 24UNA group was an independently related factor to diastolic BP as a continuous variable. The rate of appropriate BP control in patients with proteinuria was highest in 24UNA <100 mEq/L (P=0.012). The odds to fail achievement of BP target in subjects with 24UNA> or =90 mEq/day was 2.441 (1.249-4.772, P=0.009) higher than that of 24UNA <90 mEq/day among participants with proteinuria. There was difference in the amount of 24UNA between CKD and non-CKD except each stage of CKD group. In conclusion, salt intake estimated by 24-hr urine sodium excretion is a risk factor to achieve appropriate BP control.
Adult ; Aged ; Algorithms ; Blood Pressure/*physiology ; Creatine/blood ; Demography ; Female ; Humans ; Hypertension/complications ; Male ; Middle Aged ; Odds Ratio ; Proteinuria/complications ; Renal Insufficiency, Chronic/complications/*pathology ; Retrospective Studies ; Risk Factors ; Severity of Illness Index ; Sodium, Dietary/*urine ; Urine Specimen Collection

The relationship between salt intake and adequate blood pressure control is not well investigated in Korea populations, especially in patients with cardiovascular disease. This cross-sectional study enrolled 19,083 subjects who participated in the Korea National Health and Nutrition Examination Survey conducted from 2009-2011. The amount of salt intake was estimated using the Tanaka equations based on spot urine samples. Comparing patients with and without cardiovascular disease, systolic blood pressure (129.1+/-18.1 mmHg vs. 120.0+/-18.1 mmHg, P<0.001) and the amount of urinary sodium excretion (149.4+/-37.5 mM/day vs. 144.1+/-36.2 mM/day, P<0.001) were higher in patients with cardiovascular diseases. Among patients with cardiovascular disease, the high blood pressure group showed an increased amount of urinary sodium excretion compared to the normal blood pressure group (155.5+/-38.2 vs. 146.6+/-36.9 mM/day, P<0.001). The odds ratio (OR) of high blood pressure was higher (OR, 1.825; 95% CI, 1.187-2.807; P-for-trend 0.003, highest quartile of urinary sodium excretion vs. lowest quartile) in patients with cardiovascular disease. A higher amount of urinary sodium excretion was associated with a lower rate of adequate blood pressure control in Korean population, especially with cardiovascular disease.
Adult ; Aged ; Algorithms ; Blood Pressure/*physiology ; Cardiovascular Diseases/complications/*pathology ; Cross-Sectional Studies ; Demography ; Female ; Humans ; Hypertension/complications ; Male ; Middle Aged ; Nutrition Surveys ; Odds Ratio ; Sodium, Dietary/*urine