Noth R H, Lassman M N, Tan S Y, Fernandez-Cruz A, Mulrow P J
Arch Intern Med. 1977 Oct;137(10):1414-7.
Age effect on plasma renin activity (PRA) and PRA classification was studied in young and older normotensive volunteers. Ambulatory PRA was lower in the older age group than in the younger with both on an unrestricted diet and a low-sodium diet. Renal function, aldosterone excretion, and plasma renin substrate were comparable in both groups. Age had a substantial effect on PRA classification. When the young normotensives were controls, 32% (6/19) older normotensives had abnormally low PRA, or "low renin normotension." Similarly, 18% (2/11) of young patients with essential hypertension but 80% (12/15) of older hypertensives had low PRA. When the older volunteers were controls, however, the incidence of low renin hypertension (LRH) decreased to 53% in the older patients. The use of predominantly young controls for defining normal limits of PRA may result in an overestimate of the incidence of LRH and may contribute to the heterogeneity of LRH.
在年轻和年长的血压正常志愿者中研究了年龄对血浆肾素活性（PRA）及PRA分类的影响。无论是在无限制饮食还是低钠饮食情况下，老年组的动态PRA均低于年轻组。两组的肾功能、醛固酮排泄及血浆肾素底物相当。年龄对PRA分类有显著影响。以年轻血压正常者作为对照时，32%（6/19）的老年血压正常者PRA异常低，即“低肾素性血压正常”。同样，18%（2/11）的年轻原发性高血压患者及80%（12/15）的老年高血压患者PRA低。然而，以老年志愿者作为对照时，老年患者中低肾素性高血压（LRH）的发生率降至53%。主要以年轻对照来定义PRA正常范围可能会高估LRH的发生率，并可能导致LRH的异质性。
