Chinese General Practice ›› 2024, Vol. 27 ›› Issue (06): 685-691.DOI: 10.12114/j.issn.1007-9572.2022.0765

Special Issue: 高血压最新文章合集

• Original Research • Previous Articles     Next Articles

Evaluation of Estimating 24-hour Urinary Sodium Excretion from Spot Urine in Chinese Primary Hypertension Patients

  

  1. Department of Cardiology, Peking University International Hospital, Beijing 102206, China
  • Received:2022-09-30 Revised:2022-12-26 Published:2024-02-20 Online:2023-11-21
  • Contact: LIU Xiaohui

原发性高血压患者利用点尿钠估测24 h尿钠水平准确性的验证

  

  1. 102206 北京市,北京大学国际医院心内科
  • 通讯作者: 刘小慧
  • 作者简介:
    作者贡献:孙星河提出研究选题方向,负责病例资料的收集整理、统计学分析及撰写初稿;汪洋参与病例资料的收集整理;康俊萍负责论文的文字校对和修订;刘小慧负责文章质量的控制和审校,对文章整体负责;所有作者确认了论文的最终稿。

Abstract:

Background

It is important to estimate the sodium intake of primary hypertension patients through 24-hour urine sodium excretion, but the collection and testing processes are complicated. It is not clear whether the existing equation for estimating 24-hour urinary sodium excretion from spot urine sample is valid in Chinese primary hypertension patients.

Objective

To evaluate the validity of the Kawasaki, INTERSALT, and Tanaka equations using spot urine samples to estimate 24-hour urinary sodium excretion among Chinese primary hypertension patients.

Methods

This study retrospectively selected hospitalized primary hypertension patients from Department of Cardiology Peking University International Hospital from March 2018 to March 2021. General data were collected. The 24-hour urinary sodium extraction in the 24-hour urine sample was measured. The 24-hour urinary sodium extraction from spot urine sample was estimated. Paired t-test was used to measure the significance of difference between the 24-hour urine sodium excretion from spot urine samples predicted using Kawasaki, INTERSALT or Tanaka equation and measured 24-hour urinary sodium excretion from 24-hour urine collections, and the correlation and agreement between them were analyzed using the Spearman correlation coefficient and Bland–Altman plots, respectively. Relative deviation was calculated. The accuracy of the three equations were also evaluated in patients with different levels of salt intake, diabetes or proteinuria.

Results

One hundred and ninety-six patients were finally included for analysis. The average 24-hour urinary sodium excretion level was (165.04±78.53) mmol/d, which was equivalent to daily NaCl intake of (9.65±4.59) g/d. Female patients were older, had higher ratios of microalbuminuria and proteinuria, while lower BMI, diastolic blood pressure on admission, 24-hour average diastolic blood pressure compared with male patients (P<0.05) . Moreover, female patients were less likely to be smokers, and had lower spot urine sodium, as while as lower 24-hour urinary sodium excretion (P<0.05) . The 24-hour urinary sodium excretion estimated by Kawasaki equation was significantly higher than the measured value (tpaired=-8.008, P<0.001) , and the Bland-Altman plots showed that 94.90% spots were in 95%CI. The 24-hour urinary sodium excretion estimated by INTERSALT equation was significantly lower than the measured value (tpaired=4.167, P<0.001) . The Bland-Altman plots showed that 94.39% spots were in 95%CI. The 24-hour urinary sodium excretion estimated by Tanaka equation was higher than the measured value (tpaired=-0.547, P>0.05) without significant difference, and the Bland-Altman plots showed that 96.43% spots were in 95%CI. The relative deviation of Kawasaki, INTERSALT and Tanaka equations was -31.82%, 12.94 % and -1.90%, respectively. After dividing patients according to salt intake, the moderate correlation between predicted and actual values of each equation was no longer significant. There was no significant difference in the predictive accuracy of the equations between patients with and without diabetes or proteinuria.

Conclusion

The accuracy and consistency of the Kawasaki, INTERSALT and Tanaka equations in estimating 24-hour urinary sodium levels by spot urine in primary hypertension patients were poor. Tanaka's overall estimated value is the closest to the measured mean value. No comorbidity (such as diabetes, proteinuria) that might affect urinary sodium excretion was found to have a significant effect on the accuracy of the estimation equation.

Key words: Essential hypertension, Natriuresis, Diet, sodium-restricted, Diagnosis, Consistency rate

摘要: 背景 通过24 h尿钠测定计算原发性高血压患者的钠盐摄入量对指导治疗具有重要意义,但检测过程繁琐。已有的通过点尿钠估测24 h尿钠水平公式在我国原发性高血压患者中的估测价值尚不清楚。目的 评价在我国原发性高血压患者中,应用Kawasaki、INTERSALT、Tanaka公式(以下分别简称K法、I法、T法)以点尿钠估测24 h尿钠水平的准确性。方法 纳入2018年3月—2021年3月于北京大学国际医院心内科住院的原发性高血压患者为研究对象,收集患者的一般资料,测量24 h尿钠排泄量,通过点尿钠估测24 h尿钠排泄量。采用配对t检验评估3种公式24 h尿钠排泄量估测值与实测值差异的显著性,并采用Spearman秩相关分析两者的相关性。绘制Bland–Altman图对24 h尿钠排泄量实测值与估测值进行一致性分析。计算3种方法24 h尿钠排泄量估测值与实测值的相对偏差。评估在不同钠盐摄入水平、患有糖尿病、临床蛋白尿患者中3种估测公式的准确性。结果 最终纳入患者196例,平均实测24 h尿钠排泄量(165.04±78.53)mmol/d,相当于钠盐摄入量(9.65±4.59)g/d。女性患者年龄、微量蛋白尿比例、临床蛋白尿比例高于男性患者,BMI、入院舒张压、24 h平均舒张压、吸烟比例、点尿钠、实测24 h尿钠排泄量低于男性患者(P<0.05)。患者24 h尿钠排泄量实测值低于K法24 h尿钠排泄量估测值(t配对=-8.008,P<0.001),Bland-Altman散点图显示有94.90%的点在95%CI之内。患者24 h尿钠排泄量实测值高于I法24 h尿钠排泄量估测值(t配对=4.167,P<0.001),Bland-Altman散点图显示有94.39%的点在95%CI之内。患者24 h尿钠排泄量实测值与T法24 h尿钠排泄量估测值比较,差异无统计学意义(t配对=-0.547,P>0.05),Bland-Altman散点图显示有96.43%的点在95%CI之内。K法、I法、T法24 h尿钠排泄量估测值的相对偏差分别为-31.82%、12.94 %、-1.90%。根据钠盐摄入量进行分组后,估测值与实测值原本中等强度的相关性消失。三种方法的估测偏差在是否患有糖尿病、临床蛋白尿的患者之间差距不大。结论 通过K法、I法、T法在原发性高血压患者中通过点尿钠预测24 h尿钠水平上均具有偏差,但整体上T法偏差最小。未发现可能影响尿钠排泄的疾病(如糖尿病、蛋白尿)对估测公式的准确性有显著影响。

关键词: 原发性高血压, 钠尿增多, 膳食, 限钠, 诊断, 一致率