目标:在原发性醛固酮增多症(PA)中,醛固酮可通过升高肾血管阻力和肾小球毛细血管压影响肾小球血流动力学。然而,血浆醛固酮浓度(PAC)与肾小球血流动力学(包括小动脉流出阻力(Re))之间的关系,人类的传入小动脉阻力(Ra)仍不清楚。这项研究的目的是研究PAC与PA患者肾小球内血流动力学参数的关系。
方法:对17例PA患者进行肾小球血流动力学的观察性研究,同时测量对氨基马尿酸和菊粉(Cin;肾小球滤过率(GFR))的血浆清除率。肾功能由Cin评估,根据血清肌酸(eGFRcre)和血清胱抑素C(eGFRcys)和肌酸清除率(Ccr)估算GFR。肾小球内血流动力学参数,包括Re,Ra,和肾小球内静水压力(Pglo)使用戈麦斯公式计算。
结果:在17例PA病例中,PAC与Cin(rho=0.752,p=0.001)和eGFRcys(rho=0.567,p=0.018)显著相关,但与GFR和Ccr无关。PAC也与Pglo显著相关,Re,和尿蛋白/天(分别为rho=0.775,p=0.0004,rho=0.625,p=0.009和rho=0.625,p=0.007)。多因素回归分析显示PAC与Cin和Re显著相关。在比较醛固酮产生腺瘤(APA)和非APA病例时,Cin在APA中显著升高(p=0.037),而eGFRcre,eGFRcys,Ccr不是。Re在APA中趋于更高(p=0.064)。
结论:这些结果提示高醛固酮通过收缩Re引起肾小球高滤过。Cin,但不是eGFRcre和Ccr,可能对评估PA的肾功能有用。
OBJECTIVE: In primary aldosteronism (PA), aldosterone could affect glomerular hemodynamics by elevating renal vascular resistance and glomerular capillary pressure. However, the relationship between plasma aldosterone concentrations (PAC) and glomerular hemodynamics including efferent arteriolar resistance (Re), afferent arteriolar resistance (Ra) in humans is still unclear. The aim of this study was to investigate the relationships of PAC with intraglomerular hemodynamic parameters in patients with PA.
METHODS: An observational study of glomerular hemodynamics was performed using simultaneous measurements of plasma clearance of para-aminohippurate and inulin (Cin; glomerular filtration rate (GFR)) in 17 patients with PA. Kidney function was evaluated by Cin, estimated GFR based on serum creatine (eGFRcre) and serum cystatin C (eGFRcys) and creatine clearance (Ccr). Intraglomerular hemodynamic parameters, including Re, Ra, and intraglomerular hydrostatic pressure (Pglo) were calculated using Gomez\'s formulae.
RESULTS: In the 17 PA cases, PAC was significantly correlated with Cin (rho=0.752, p=0.001) and eGFRcys (rho=0.567, p=0.018), but was not correlated witheGFRcreand Ccr. PAC was also significantly correlated with Pglo, Re, and urinary protein/day (rho=0.775, p=0.0004, rho=0.625, p=0.009, and rho=0.625, p=0.007, respectively). Multivariable regression analysis showed that PAC was significantly associated with Cin and Re. In comparing aldosterone producing adenoma (APA) and non-APA cases, Cin was significantly elevated in APA (p=0.037), whereas eGFRcre, eGFRcys, and Ccr were not. Re tended to be higher in APA (p=0.064).
CONCLUSIONS: These results suggest high aldosterone cause glomerular hyperfiltration by constricting Re. Cin, but not eGFRcre and Ccr, may be useful for evaluating kidney function in PA.