Limits...
Estimation of salt intake from spot urine samples in patients with chronic kidney disease.

Ogura M, Kimura A, Takane K, Nakao M, Hamaguchi A, Terawaki H, Hosoya T - BMC Nephrol (2012)

Bottom Line: Estimated sodium excretion significantly correlated with measured sodium excretion (R = 0.52, P < 0.01).Estimated sodium excretion had high accuracy to predict measured sodium excretion, especially when the cut-off point was >170 mEq/day (AUC 0.835).The present study demonstrated that spot urine can be used to estimate sodium excretion, especially in patients with low eGFR.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Kidney and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Nishi-shinbashi, Minato-ku, Tokyo, Japan.Themogura@jikei.ac.jp.

ABSTRACT

Background: High salt intake in patients with chronic kidney disease (CKD) may cause high blood pressure and increased albuminuria. Although, the estimation of salt intake is essential, there are no easy methods to estimate real salt intake.

Methods: Salt intake was assessed by determining urinary sodium excretion from the collected urine samples. Estimation of salt intake by spot urine was calculated by Tanaka's formula. The correlation between estimated and measured sodium excretion was evaluated by Pearson´s correlation coefficients. Performance of equation was estimated by median bias, interquartile range (IQR), proportion of estimates within 30% deviation of measured sodium excretion (P30) and root mean square error (RMSE).The sensitivity and specificity of estimated against measured sodium excretion were separately assessed by receiver-operating characteristic (ROC) curves.

Results: A total of 334 urine samples from 96 patients were examined. Mean age was 58 ± 16 years, and estimated glomerular filtration rate (eGFR) was 53 ± 27 mL/min. Among these patients, 35 had CKD stage 1 or 2, 39 had stage 3, and 22 had stage 4 or 5. Estimated sodium excretion significantly correlated with measured sodium excretion (R = 0.52, P < 0.01). There was apparent correlation in patients with eGFR <30 mL/min (R = 0.60, P < 0.01). Moreover, IQR was lower and P30 was higher in patients with eGFR < 30 mL/min. Estimated sodium excretion had high accuracy to predict measured sodium excretion, especially when the cut-off point was >170 mEq/day (AUC 0.835).

Conclusions: The present study demonstrated that spot urine can be used to estimate sodium excretion, especially in patients with low eGFR.

No MeSH data available.


Related in: MedlinePlus

Accuracy and precision of estimates expressed as P30 and IQR categorized by eGFR. Highest accuracy within 30% and lowest precision were found for samples with an eGFR <30 mL/min. P30: percentage of estimated sodium intake within 30% of measured sodium intake, IQR: interquartile range
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3472175&req=5

Figure 4: Accuracy and precision of estimates expressed as P30 and IQR categorized by eGFR. Highest accuracy within 30% and lowest precision were found for samples with an eGFR <30 mL/min. P30: percentage of estimated sodium intake within 30% of measured sodium intake, IQR: interquartile range

Mentions: Table 2 demonstrated performance of urinary sodium estimating equation in patients with CKD. Median bias was 4.5 and percentage bias was 2.7%. IQR, an indicator of precision, was 53 mEq/ day. RMSE and P30, an indicator of accuracy, were 50 mEq/ day and 70%, respectively in overall patients. For each of the eGFR equations, the dataset was split into 3 groups: eGFR <30, 30–60, and >60 mL/min. Median bias and IQR were lower in patients with eGFR < 30 mL/min. Moreover, RMSE was lower and P30 was higher in patients at lower levels of eGFR (Table 2, Figure 4).


Estimation of salt intake from spot urine samples in patients with chronic kidney disease.

Ogura M, Kimura A, Takane K, Nakao M, Hamaguchi A, Terawaki H, Hosoya T - BMC Nephrol (2012)

Accuracy and precision of estimates expressed as P30 and IQR categorized by eGFR. Highest accuracy within 30% and lowest precision were found for samples with an eGFR <30 mL/min. P30: percentage of estimated sodium intake within 30% of measured sodium intake, IQR: interquartile range
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472175&req=5

Figure 4: Accuracy and precision of estimates expressed as P30 and IQR categorized by eGFR. Highest accuracy within 30% and lowest precision were found for samples with an eGFR <30 mL/min. P30: percentage of estimated sodium intake within 30% of measured sodium intake, IQR: interquartile range
Mentions: Table 2 demonstrated performance of urinary sodium estimating equation in patients with CKD. Median bias was 4.5 and percentage bias was 2.7%. IQR, an indicator of precision, was 53 mEq/ day. RMSE and P30, an indicator of accuracy, were 50 mEq/ day and 70%, respectively in overall patients. For each of the eGFR equations, the dataset was split into 3 groups: eGFR <30, 30–60, and >60 mL/min. Median bias and IQR were lower in patients with eGFR < 30 mL/min. Moreover, RMSE was lower and P30 was higher in patients at lower levels of eGFR (Table 2, Figure 4).

Bottom Line: Estimated sodium excretion significantly correlated with measured sodium excretion (R = 0.52, P < 0.01).Estimated sodium excretion had high accuracy to predict measured sodium excretion, especially when the cut-off point was >170 mEq/day (AUC 0.835).The present study demonstrated that spot urine can be used to estimate sodium excretion, especially in patients with low eGFR.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Kidney and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Nishi-shinbashi, Minato-ku, Tokyo, Japan.Themogura@jikei.ac.jp.

ABSTRACT

Background: High salt intake in patients with chronic kidney disease (CKD) may cause high blood pressure and increased albuminuria. Although, the estimation of salt intake is essential, there are no easy methods to estimate real salt intake.

Methods: Salt intake was assessed by determining urinary sodium excretion from the collected urine samples. Estimation of salt intake by spot urine was calculated by Tanaka's formula. The correlation between estimated and measured sodium excretion was evaluated by Pearson´s correlation coefficients. Performance of equation was estimated by median bias, interquartile range (IQR), proportion of estimates within 30% deviation of measured sodium excretion (P30) and root mean square error (RMSE).The sensitivity and specificity of estimated against measured sodium excretion were separately assessed by receiver-operating characteristic (ROC) curves.

Results: A total of 334 urine samples from 96 patients were examined. Mean age was 58 ± 16 years, and estimated glomerular filtration rate (eGFR) was 53 ± 27 mL/min. Among these patients, 35 had CKD stage 1 or 2, 39 had stage 3, and 22 had stage 4 or 5. Estimated sodium excretion significantly correlated with measured sodium excretion (R = 0.52, P < 0.01). There was apparent correlation in patients with eGFR <30 mL/min (R = 0.60, P < 0.01). Moreover, IQR was lower and P30 was higher in patients with eGFR < 30 mL/min. Estimated sodium excretion had high accuracy to predict measured sodium excretion, especially when the cut-off point was >170 mEq/day (AUC 0.835).

Conclusions: The present study demonstrated that spot urine can be used to estimate sodium excretion, especially in patients with low eGFR.

No MeSH data available.


Related in: MedlinePlus