Determinants of glomerular hypofiltration in aging humans
Determinants of glomerular hypofiltration in aging humans
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DOI：
10.1046/j.1523-1755.2003.00207.x
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发表时间：
2003-10-01
影响因子：
19.6
通讯作者：
Myers, BD
中科院分区：
文献类型：
--
作者：
Hoang, K;Tan, JC;Myers, BD
背景。本研究的目的是确认健康、老龄受试者肾小球滤过率 (GFR) 下降的程度，并阐明这种低滤过的机制。方法。 18 至 88 岁的健康志愿者 (N = 159) 接受了 GFR、肾血浆流量 (RPF)、传入胶体渗透压和动脉压的测定。对23至69岁健康肾移植捐献者（N = 33）肾活检中的肾小球进行形态学分析，以确定肾小球水力渗透性和滤过表面积。然后对上述 GFR 决定因素进行数学建模，以计算两个肾脏和单个肾小球的肾小球超滤系数 (K-f)。结果。与年轻受试者（≤40 岁）相比，老龄化受试者（≥55 岁）的 GFR 显着降低（P < 0.0001）22%。老年组与年轻组中以下 GFR 决定因素的相应降低包括 RPF 降低 28% (P < 0.0001)、双肾 K-f 降低 21% 至 53% (P < 0.005)、肾小球水力通透性降低 14% (P = 0.03) 和单肾单位 K-f (SNKf) 降低 30% (P = 0.09）。老年组和年轻组之间的传入胶体渗透压和每个肾小球的滤过表面积没有显着差异。结论。我们得出的结论是，总体两肾 K-f 的降低会导致老年受试者的 GFR 降低。我们推断，这部分是由于结构变化降低了 SNKf，部分是由于其他人在尸检中证明的功能性肾小球实际数量的减少。
Background. The purpose of the present study was to confirm the extent to which glomerular filtration rate (GFR) is depressed in healthy, aging subjects and to elucidate the mechanism of such hypofiltration.Methods. Healthy volunteers aged 18 to 88 years (N = 159) underwent a determination of GFR, renal plasma flow (RPF), afferent oncotic pressure, and arterial pressure. Glomeruli in renal biopsies of healthy kidney transplant donors aged 23 to 69 years (N = 33) were subjected to a morphometric analysis, so as to determine glomerular hydraulic permeability and filtration surface area. The aforementioned GFR determinants were then subjected to mathematical modeling to compute the glomerular ultrafiltration coefficient (K-f) for two kidneys and individual glomeruli.Results. GFR was significantly depressed (P < 0.0001) by 22% in aging (≥55 years old) compared to youthful subjects (≤40 years old). Corresponding reductions of the following GFR determinants in the aging vs. youthful subsets were RPF by 28% (P < 0.0001), two-kidney K-f by 21% to 53% (P < 0.005), glomerular hydraulic permeability by 14% (P = 0.03), and the single-nephron K-f (SNKf) by 30% (P = 0.09). There were no significant differences between aging and youthful subsets for afferent oncotic pressure and filtration surface area per glomerulus.Conclusion. We conclude that a reduction in overall, two-kidney K-f contributes to GFR depression in aging subjects. We infer that this is due in part to structural changes that lower SNKf, and in part to the reduction in the actual number of functioning glomeruli that has been demonstrated by others at autopsy.