Luft F C, Fineberg N S, Weinberger M H
Department of Internal Medicine-Nephrology, University of Erlangen-Nürnberg, Germany.
Am J Hypertens. 1992 Aug;5(8):520-8. doi: 10.1093/ajh/5.8.520.
To determine the effects of age on the responses of renin, aldosterone (PA), sodium excretion, and renal function to provocative maneuvers, we performed volume expansion and contraction in 390 normotensive and 212 hypertensive subjects in the second to seventh decades of life. The subjects were classified as Na-sensitive if their mean blood pressure was 10 mm Hg or more higher after volume expansion than volume contraction. Sodium sensitivity was associated with hypertension and increasing age. Plasma renin activity decreased with age under basal, stimulated, and suppressed conditions; the decrease was greater in hypertensives than in normotensive persons. The PA values were greater in hypertensives than in normal subjects after volume expansion. There was an age-related decrease in PA values after volume contraction in normal, but not in hypertensive, persons. With volume expansion, hypertensive persons exhibited "exaggerated natriuresis." There was an age-related increase in natriuresis in both groups; the increase was greater in hypertensives than normal subjects. Creatinine clearance decreased with age; however, the rate of decrease in this cross-sectional study was not different in hypertensive and normotensive subjects. These observations may have a bearing on why NaCl affects the blood pressures of older individuals more than younger persons.
为了确定年龄对肾素、醛固酮（PA）、钠排泄以及肾功能对激发性操作反应的影响，我们对390名血压正常者和212名高血压患者进行了容量扩充和收缩试验，这些受试者年龄在20岁至70岁之间。如果受试者在容量扩充后的平均血压比容量收缩后高10毫米汞柱或更多，则将其归类为钠敏感型。钠敏感性与高血压和年龄增长有关。在基础、刺激和抑制条件下，血浆肾素活性均随年龄下降；高血压患者的下降幅度大于血压正常者。容量扩充后，高血压患者的PA值高于正常受试者。正常人群容量收缩后PA值随年龄下降，而高血压患者则不然。容量扩充时，高血压患者表现出“过度利钠”。两组的利钠作用均随年龄增加；高血压患者的增加幅度大于正常受试者。肌酐清除率随年龄下降；然而，在这项横断面研究中，高血压患者和血压正常者的下降速率并无差异。这些观察结果可能有助于解释为什么氯化钠对老年人血压的影响大于年轻人。
