Abstract：
BACKGROUND: Lowering dietary salt intake reduces albuminuria, an early marker of renal damage and a sensitive predictor of adverse cardiovascular outcomes. The mechanisms underlying this effect are uncertain but small changes in serum sodium concentration may be important: this retrospective cohort study investigated the hypothesis that higher serum sodium concentration is a risk factor for albuminuria (defined as a urine albumin:creatinine ratio [UACR], ≥3 mg/mmol).
METHODS: Primary care data from the Royal College of General Practitioners Research and Surveillance Centre were used to identify 47,294 individuals with a UACR result available between April 2010 and March 2015, and no known albuminuria prior to this. Exclusion criteria were missing or abnormal serum sodium concentration at baseline (<135 or >146 mmol/L); age <18 years; diabetes mellitus; decompensated liver disease; heart failure; and stage 5 chronic kidney disease.
RESULTS: After adjustment for known risk factors, there was a significant \"U-shaped\" relationship between serum sodium concentration and albuminuria. The lowest risk was associated with a serum sodium of 138-140 mmol/L. In comparison, the risk of albuminuria was 18% higher with a serum sodium of 135-137 mmol/L and 19% higher with a serum sodium of 144-146 mmol/L. There was no association between serum sodium concentration and blood pressure.
CONCLUSIONS: The finding of a positive association between higher serum sodium concentration and albuminuria is in support of the hypothesis, but the inverse relationship between serum sodium concentration and albuminuria at lower concentrations warrants further explanation.
METHODS: Primary care data from the Royal College of General Practitioners Research and Surveillance Centre were used to identify 47,294 individuals with a UACR result available between April 2010 and March 2015, and no known albuminuria prior to this. Exclusion criteria were missing or abnormal serum sodium concentration at baseline (<135 or >146 mmol/L); age <18 years; diabetes mellitus; decompensated liver disease; heart failure; and stage 5 chronic kidney disease.
RESULTS: After adjustment for known risk factors, there was a significant \"U-shaped\" relationship between serum sodium concentration and albuminuria. The lowest risk was associated with a serum sodium of 138-140 mmol/L. In comparison, the risk of albuminuria was 18% higher with a serum sodium of 135-137 mmol/L and 19% higher with a serum sodium of 144-146 mmol/L. There was no association between serum sodium concentration and blood pressure.
CONCLUSIONS: The finding of a positive association between higher serum sodium concentration and albuminuria is in support of the hypothesis, but the inverse relationship between serum sodium concentration and albuminuria at lower concentrations warrants further explanation.
摘要：
背景：降低膳食盐摄入量可减少白蛋白尿，肾损害的早期标志物和心血管不良结局的敏感预测指标.这种效应的潜在机制尚不确定，但血清钠浓度的微小变化可能很重要：这项回顾性队列研究调查了以下假设：较高的血清钠浓度是白蛋白尿的危险因素（定义为尿白蛋白：肌酐比率，或UACR，≥3mg/mmol)。
方法：使用来自皇家全科医师研究和监测中心的初级保健数据，在2010年4月至2015年3月期间，有47,294名UACR结果的个体被用于鉴定，在此之前没有已知的白蛋白尿。排除标准为：基线血清钠浓度缺失或异常（<135或146mmol/L）；年龄18岁；糖尿病；失代偿性肝病；心力衰竭；和5期慢性肾病。
结果：对已知风险因素进行调整后，血清钠浓度与白蛋白尿之间存在显著的U型关系。最低的风险与138-140mmol/L的血清钠有关。相比之下,血清钠为135-137mmol/L时，白蛋白尿的风险增加18％，血清钠为144-146mmol/L时，白蛋白尿的风险增加19％。血清钠浓度与血压之间没有相关性。
结论：血清钠浓度升高与白蛋白尿呈正相关的发现支持了这一假设，但在较低浓度时，血清钠浓度与白蛋白尿之间的反比关系值得进一步解释。
方法：使用来自皇家全科医师研究和监测中心的初级保健数据，在2010年4月至2015年3月期间，有47,294名UACR结果的个体被用于鉴定，在此之前没有已知的白蛋白尿。排除标准为：基线血清钠浓度缺失或异常（<135或146mmol/L）；年龄18岁；糖尿病；失代偿性肝病；心力衰竭；和5期慢性肾病。
结果：对已知风险因素进行调整后，血清钠浓度与白蛋白尿之间存在显著的U型关系。最低的风险与138-140mmol/L的血清钠有关。相比之下,血清钠为135-137mmol/L时，白蛋白尿的风险增加18％，血清钠为144-146mmol/L时，白蛋白尿的风险增加19％。血清钠浓度与血压之间没有相关性。
结论：血清钠浓度升高与白蛋白尿呈正相关的发现支持了这一假设，但在较低浓度时，血清钠浓度与白蛋白尿之间的反比关系值得进一步解释。
