Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Italy.
Department of Clinical and Experimental Medicine, University of Pisa, Italy.
Obesity (Silver Spring). 2019 Jan;27(1):68-74. doi: 10.1002/oby.22355. Epub 2018 Dec 5.
Bariatric surgery may ameliorate renal function through vascular mechanisms. This study tested surgery's ability to improve measured glomerular filtration rate (mGFR) and identified clinical, renal, and systemic vascular predictors of such improvement.
Twenty-five nondiabetic subjects with severe obesity were studied before and 1 year after Roux-en-Y gastric bypass, evaluating mGFR and renal plasma flow, basal renal resistive index (RI) and dynamic renal RI, renal visceral fat, and systemic vascular parameters, including flow-mediated dilation, aortic pulse wave velocity, and carotid intima media thickness and stiffness.
After Roux-en-Y gastric bypass, BMI decreased by 31%. At follow-up, body surface area (BSA)-adjusted mGFR increased (from 86.9 ± 15.2 to 109.0 ± 18.2 mL/min/1.73 m , P < 0.001), whereas the absolute mGFR did not change. Renal plasma flow did not vary. RI decreased; flow-mediated dilation, pulse wave velocity, carotid intima media thickness, and carotid stiffness improved. mGFR changes after surgery (ΔmGFR/BSA) were associated with younger age and lower fasting glucose. Among vascular variables, an improved ΔmGFR/BSA was associated with smaller brachial artery diameter, lower intima media thickness, and lower RI; this latter association remained after adjusting for covariates. No measure of adiposity was associated with ΔmGFR.
In subjects with obesity and normal renal function, bariatric surgery improves mGFR/BSA (although absolute mGFR is unchanged) and renal and systemic vascular function. Lower renal intravascular resistance can predict these improvements, maximizing them in relatively young individuals.
减重手术可能通过血管机制改善肾功能。本研究测试了手术改善肾小球滤过率（mGFR）的能力，并确定了这种改善的临床、肾脏和全身血管预测因素。
25 名非糖尿病严重肥胖患者在 Roux-en-Y 胃旁路术前和术后 1 年进行研究，评估 mGFR 和肾血浆流量、基础肾阻力指数（RI）和动态肾 RI、肾内脏脂肪以及包括血流介导的扩张、主动脉脉搏波速度、颈动脉内膜中层厚度和硬度在内的全身血管参数。
Roux-en-Y 胃旁路术后，BMI 降低了 31%。在随访时，BSA 校正的 mGFR 增加（从 86.9±15.2 到 109.0±18.2 mL/min/1.73 m 2 ，P<0.001），而绝对 mGFR 没有变化。肾血浆流量没有变化。RI 降低；血流介导的扩张、脉搏波速度、颈动脉内膜中层厚度和颈动脉硬度改善。手术后 mGFR 的变化（ΔmGFR/BSA）与年龄较小和空腹血糖较低有关。在血管变量中，改善的 ΔmGFR/BSA 与肱动脉直径较小、内膜中层厚度较低和 RI 较低有关；在调整了协变量后，这种相关性仍然存在。肥胖的任何指标都与 ΔmGFR 无关。
在肥胖且肾功能正常的患者中，减重手术可改善 mGFR/BSA（尽管绝对 mGFR 不变）和肾脏及全身血管功能。较低的肾血管内阻力可以预测这些改善，在相对年轻的患者中最大限度地提高这些改善。
