The spot urinary sodium-to-potassium (Na/K) ratio is a simple measure of salt loading and has been shown to be associated with elevated blood pressure (BP) in middle-aged and older adults. This study aimed to evaluate the association between the spot urinary Na/K ratio and BP in 457 healthy adolescents aged 12–15 years in a school-based setting. The mean urinary Na/K ratio was 4.99 ± 2.76, and no significant difference was found between the boys and girls. When the participants were stratified based on urinary Na/K ratio quartile, age- and sex-adjusted systolic and diastolic BP gradually increased as Na/K ratio increased (systolic BP: 106.1, 106.9, 108.2, and 111.5 mmHg, P_trend < 0.001; diastolic BP: 62.0, 62.4, 63.1, 64.3 mmHg, P_trend = 0.022). The systolic and diastolic BP were more closely associated with urinary Na/K ratio than with Na and K levels, as well as estimated daily salt intake. In the multiple regression analysis, the urinary Na/K ratio was significantly associated with systolic BP (β = 0.144, P < 0.001) and diastolic BP (β = 0.114, P = 0.015) independent of potential confounding factors. An additional subgroup analysis revealed that the BP of the group with both high salt intake (≥8.5 g/day) and high Na/K ratio (≥6.60) was significantly higher than that of the group with high salt intake alone (systolic BP, 115.0 vs. 109.1 mmHg, P < 0.001; diastolic BP, 66.0 vs. 62.5 mmHg, P = 0.017). These results suggest that the urinary Na/K ratio is associated with BP levels in healthy adolescents and may be useful for assessing salt loading and its effects on BP elevation.

点尿钠钾 (Na/K) 比率是盐负荷的简单测量方法，已被证明与中老年人血压 (BP) 升高相关。本研究旨在评估学校环境中 457 名 12-15 岁健康青少年的点尿 Na/K 比值与血压之间的关联。尿Na/K比值平均为4.99±2.76，男女生差异无统计学意义。当根据尿Na/K比四分位数对参与者进行分层时，年龄和性别调整后的收缩压和舒张压随着Na/K比的增加而逐渐增加（收缩压：106.1、106.9、108.2和111.5 mmHg，P_趋势 < 0.001；舒张压：62.0、62.4、63.1、64.3 mmHg， P_趋势 = 0.022）。收缩压和舒张压与尿钠/钾比的关系比与钠和钾水平以及估计每日盐摄入量的关系更密切。多元回归分析显示，尿Na/K比值与收缩压显着相关（β = 0.144， P < 0.001) 和舒张压 (β = 0.114, P  = 0.015）独立于潜在的混杂因素。另一项亚组分析显示，同时高盐摄入（≥8.5g/天）和高Na/K比值（≥6.60）组的血压显着高于单独高盐摄入组（收缩压、 115.0 vs. 109.1 mmHg，P < 0.001；舒张压，66.0 vs. 62.5 mmHg，P = 0.017)。这些结果表明，尿钠/钾比与健康青少年的血压水平相关，可能有助于评估盐负荷及其对血压升高的影响。