Osanai T, Okuguchi T, Kamada T, Fujiwara N, Kosugi T, Saitoh G, Katoh T, Nakano T, Takahashi K, Guan W, Okumura K
The Second Department of Internal Medicine, Hirosaki University School of Medicine, Hirosaki, Japan.
J Hum Hypertens. 2000 Jan;14(1):57-64. doi: 10.1038/sj.jhh.1000945.
The morning surge in blood pressure (BP) is related to the morning occurrence of lethal cardiovascular events. We tested the hypothesis that salt intake may be associated with the morning surge in BP in essential hypertension. Seventy-six patients were admitted and placed on a low salt diet (2 g/day) for 7 days followed by a high salt diet (20-23 g/day) for another 7 days. At the end of each salt diet, 24-h ambulatory BP and heart rate monitorings and head-up tilt (HUT) test were performed. Patients whose average mean BP (MBP) was increased by more than 10% by salt loading were assigned to the salt-sensitive (SS) group (n = 37); the remaining patients, whose MBP was increased by less than 10%, were assigned to the non-salt-sensitive (NSS) group (n = 39). The increase in ambulatory MBP during 6.30-8.00 am above the baseline (2.00-4.00 am) was significantly enhanced by salt loading in the NSS group (P < 0.05), but not in the SS group. The coefficient of variation of 24-h MBP and heart rate was increased by salt loading only in the NSS group. The significant elevation of plasma noradrenaline concentration after awakening, which was noted during the low salt diet period, was unchanged during the high salt diet period in the NSS group, but abolished in the SS group. Salt loading enhanced HUT-induced decrease in systolic BP without affecting the heart rate response only in the NSS group. We conclude that the morning surge in BP is enhanced by salt loading in the NSS type of essential hyper- tension, presumably by the excessive activation of the sympathetic nervous system. Journal of Human Hypertension (2000) 14, 57-64.
血压晨峰与致死性心血管事件的早晨发作有关。我们检验了这样一个假设：盐摄入量可能与原发性高血压患者的血压晨峰有关。76例患者入院，先接受7天的低盐饮食（2克/天），然后再接受7天的高盐饮食（20 - 23克/天）。在每种盐饮食结束时，进行24小时动态血压和心率监测以及头高位倾斜（HUT）试验。盐负荷使平均动脉压（MBP）升高超过10%的患者被分配到盐敏感（SS）组（n = 37）；其余MBP升高不到10%的患者被分配到非盐敏感（NSS）组（n = 39）。NSS组在上午6:30 - 8:00期间动态MBP较基线（凌晨2:00 - 4:00）的升高在盐负荷后显著增强（P < 0.05），而SS组未出现这种情况。仅在NSS组中，盐负荷使24小时MBP和心率的变异系数增加。低盐饮食期间观察到的觉醒后血浆去甲肾上腺素浓度的显著升高，在NSS组的高盐饮食期间未改变，但在SS组中消失。仅在NSS组中，盐负荷增强了HUT诱导的收缩压下降，而不影响心率反应。我们得出结论，在NSS型原发性高血压中，盐负荷会增强血压晨峰，可能是通过交感神经系统的过度激活。《人类高血压杂志》（2000年）14卷，57 - 64页。
