Department of Cardiology, West China Hospital, Sichuan University, Chengdu, China.
J Clin Hypertens (Greenwich). 2021 Oct;23(10):1907-1914. doi: 10.1111/jch.14356. Epub 2021 Sep 3.
Research reports on associations of urinary sodium excretion with central hemodynamic parameters and vascular changes are quite limited in general or non-hypertensive population. The purpose of the current study was to explore such associations in Chinese general Tibetans living at high altitude. This cross-sectional study was conducted in Luhuo County, Ganzi Tibetan Autonomous Prefecture with average elevation of 3800 meters from December 2018 to January 2019. A total of 294 Tibetans were included in the current study. Twenty-four hour urinary sodium excretion was estimated by second fasting spot urine in the morning using Kawasaki formula. Central hemodynamic parameters, including central systolic blood pressure (CSBP), central diastolic blood pressure (CDBP), central pulse pressure (CPP), central mean arterial pressure (CMAP), augmentation pressure (AP), and augmentation index standardized for heart rate of 75 (AIx ), were evaluated using the SphygmoCor system. Vascular structures and functions were assessed by carotid intima media thickness (CIMT) test and brachial ankle pulse wave velocity (baPWV), respectively. Estimated mean 24h urinary sodium excretion of Tibetans in Luhuo County was 5.26±1.61 g. After adjustment, estimated 24h urinary sodium was positively associated with CSBP (β = 1.15, p = .008) and CPP (β = 0.87, p = .013). Line graph of means across urinary sodium quartiles showed that associations of 24 h urinary sodium excretion with AIx and baPWV presented approximate "J" shape after controlling for confounders. Estimated 24 h sodium excretion was independently and positively associated with CSBP and CPP. Moreover, association between urinary sodium excretion and arterial elasticity, as evaluated by baPWV and AIx , presented "J" shape. Further studies are needed to verify J-shaped association and "safe" zone of sodium intake.
研究报告表明，一般人群或非高血压人群中，尿钠排泄与中心血液动力学参数和血管变化之间的关联相当有限。本研究的目的是探讨生活在高海拔地区的中国藏族人群中的这种关联。本横断面研究于 2018 年 12 月至 2019 年 1 月在甘孜藏族自治州炉霍县进行，平均海拔 3800 米。本研究共纳入 294 名藏族人。采用川崎公式，通过早晨第二次空腹晨尿估算 24 小时尿钠排泄量。采用 SphygmoCor 系统评估中心收缩压（CSBP）、中心舒张压（CDBP）、中心脉压（CPP）、中心平均动脉压（CMAP）、增强压（AP）和心率标准化的增强指数（AIx）等中心血液动力学参数。通过颈动脉内膜中层厚度（CIMT）试验和肱踝脉搏波速度（baPWV）分别评估血管结构和功能。炉霍县藏族人估计的平均 24 小时尿钠排泄量为 5.26±1.61 g。调整后，估计的 24 小时尿钠与 CSBP（β=1.15，p=0.008）和 CPP（β=0.87，p=0.013）呈正相关。在控制混杂因素后，24 小时尿钠四分位数均值的折线图显示，24 小时尿钠排泄与 AIx 和 baPWV 的关联呈近似“J”形。估计的 24 小时钠排泄与 CSBP 和 CPP 呈独立正相关。此外，baPWV 和 AIx 评估的动脉弹性与尿钠排泄之间的关联呈“J”形。需要进一步的研究来验证 J 形关联和钠摄入量的“安全”范围。
