Uzu T, Fujii T, Nishimura M, Kuroda S, Nakamura S, Inenaga T, Kimura G
Division of Nephrology, National Cardiovascular Center, Osaka, Japan.
Am J Hypertens. 1999 Jan;12(1 Pt 1):35-9. doi: 10.1016/s0895-7061(98)00182-4.
It has been postulated that the lack of nocturnal blood pressure fall in patients called nondippers is associated with more serious end organ damages by hypertension than in dippers whose blood pressure falls during the night. Recently, we found that sodium restriction shifted circadian rhythm of blood pressure from that of a nondipper to a dipper in patients with essential hypertension. In the present study, we aimed to clarify these important findings from the different approaches, and examined which factors affected the diurnal rhythm of blood pressure. A total of 70 patients with essential hypertension were maintained on high and low sodium diets for 1 week each. Nocturnal fall in mean arterial pressure was calculated in each patient, and, based on multiple regression analysis, independent factors affecting this nocturnal fall were examined. Thirty-eight patients were classified as non-sodium-sensitive, whereas 32 were considered sodium sensitive, based on a >10% change in 24-h mean arterial pressure by sodium restriction. In all 70 patients, sodium sensitivity of blood pressure, as well as an interaction between sodium sensitivity and sodium restriction, were identified as independent factors affecting the nocturnal fall. In sodium-sensitive types, in addition to sodium restriction, glomerular filtration rate was identified, whereas, in non-sodium sensitive types, there was no significant factor. Based on multiple regression analysis, the present study reached the same important conclusion as our previous findings: namely, that the enhanced sodium sensitivity was an independent determinant for the diminished nocturnal fall in essential hypertension and that sodium restriction could restore the nocturnal decline, especially in patients with enhanced sodium sensitivity whose nocturnal decline was diminished. Reduced renal sodium excretory capability may be one of the mechanisms involved in nondipping.
据推测，血压在夜间不降的患者（称为非杓型血压者），与夜间血压下降的杓型血压者相比，高血压对终末器官的损害更严重。最近，我们发现限钠可使原发性高血压患者的血压昼夜节律从非杓型转变为杓型。在本研究中，我们旨在从不同角度阐明这些重要发现，并研究哪些因素影响血压的昼夜节律。70例原发性高血压患者分别接受高钠和低钠饮食1周。计算每位患者平均动脉压的夜间下降幅度，并基于多元回归分析，研究影响这种夜间下降的独立因素。根据限钠后24小时平均动脉压变化>10%，38例患者被分类为非钠敏感型，32例被认为是钠敏感型。在所有70例患者中，血压的钠敏感性以及钠敏感性与限钠之间的相互作用被确定为影响夜间血压下降的独立因素。在钠敏感型患者中，除限钠外，还确定了肾小球滤过率，而在非钠敏感型患者中，没有显著因素。基于多元回归分析，本研究得出了与我们之前的发现相同的重要结论：即钠敏感性增强是原发性高血压患者夜间血压下降减弱的独立决定因素，限钠可恢复夜间血压下降，尤其是在钠敏感性增强且夜间血压下降减弱的患者中。肾钠排泄能力降低可能是血压非勺型变化的机制之一。
