Hollenberg N K, Rivera A, Meinking T, Martinez G, McCullough M, Passan D, Preston M, Taplin D, Vicaria-Clement M
Department of Medicine and Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
Nephron. 1999 Jun;82(2):131-8. doi: 10.1159/000045389.
BACKGROUND/AIMS: Among possible contributors to a progressive fall in renal perfusion and function with increasing age, some hypotheses have invoked the rise in blood pressure that occurs with age, and a high-protein diet typical of urban cultures. Kuna Amerinds residing in isolated islands off the Panamanian Coast have a very low protein intake and show no tendency for blood pressure to rise with age, thus providing an opportunity to test these hypotheses.
We measured renal plasma flow and glomerular filtration rate (PAH and inulin clearance) in 16 Kuna Indians ranging in age from 18 to 86 years (51 +/- 6 years) who have resided on Ailigandi, an isolated Panamanian island for all of their lives. Inulin and PAH were infused with a battery-driven pump for 60 min, and a metabolic clearance rate used to calculate inulin and PAH clearance. For comparison, we employed identical techniques in 29 residents of Boston, ranging in age from 19 to 79 years (52 +/- 4 years), all normotensive and free of disease or medication use. Twenty-four were Caucasian.
The Bostonian controls showed the anticipated fall in PAH clearance with age (y = 806 - 4.9 x; r = -0.82; f = 38.0; p < 0.0001). Our hypothesis was that the absence of a blood pressure rise with age and the low protein intake would flatten the slope relating renal perfusion to Kuna age. Our finding was a numerically steeper slope relating age and renal plasma flow in the Kuna (y = 936 - 6.48x; r = -0.81; p < 0.001). Filtration fraction rose with age in both populations, and again the rise was steeper in the Kuna. GFR in the Kuna, on the other hand, was very much higher at any age (139 +/- 4 ml/min/1.73 m2) than in Bostonians (112 +/- 3 ml/min/1.73 m2; p < 0.001).
The findings are not in accord with the hypothesis that age-related changes in renal perfusion and glomerular filtration rate reflect an important contribution from blood pressure rise and a high protein intake, typical of modern, urban life.
背景/目的：随着年龄增长，肾脏灌注和功能逐渐下降，在可能的影响因素中，一些假说认为与年龄相关的血压升高以及城市文化中典型的高蛋白饮食有关。居住在巴拿马海岸外孤立岛屿上的库纳印第安人蛋白质摄入量极低，且未表现出血压随年龄增长而升高的趋势，这为检验这些假说提供了机会。
我们测量了16名年龄在18至86岁（平均51±6岁）的库纳印第安人的肾血浆流量和肾小球滤过率（对氨基马尿酸和菊粉清除率），他们一生都居住在巴拿马的孤立岛屿艾利甘迪岛。用电池驱动的泵输注菊粉和对氨基马尿酸60分钟，并用代谢清除率来计算菊粉和对氨基马尿酸清除率。为作比较，我们对29名年龄在19至79岁（平均52±4岁）的波士顿居民采用了相同技术，他们均血压正常，无疾病且未服用药物。其中24人为白种人。
波士顿对照组的对氨基马尿酸清除率随年龄增长呈预期下降（y = 806 - 4.9x；r = -0.82；F = 38.0；p < 0.0001）。我们的假说是，由于年龄增长时血压未升高且蛋白质摄入量低，将使肾灌注与库纳人年龄之间关系的斜率变平缓。我们的发现是，库纳人年龄与肾血浆流量之间的斜率在数值上更陡（y = 936 - 6.48x；r = -0.81；p < 0.001）。两个群体的滤过分数均随年龄增长，且库纳人的增长更为陡峭。另一方面，库纳人在任何年龄的肾小球滤过率（139±4 ml/min/1.73 m²）都比波士顿人（112±3 ml/min/1.73 m²；p < 0.001）高得多。
这些发现与以下假说不符，即与年龄相关的肾灌注和肾小球滤过率变化反映了血压升高和高蛋白摄入（现代城市生活的典型特征）的重要影响。
