Bancu Ioana, Navarro Díaz Maruja, Serra Assumpta, Granada Marisa, Lopez Dolores, Romero Ramon, Bonet Josep
Department of Nephrology, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain.
Universitat Autònoma de Barcelona, Barcelona, Spain.
PLoS One. 2016 May 3;11(5):e0154451. doi: 10.1371/journal.pone.0154451. eCollection 2016.
IGF-1 (insulin-like growth factor-1) is a hormone involved in cell growth and other important processes. In the kidney, IGF-1 has a stimulating effect, increasing the blood flow and glomerular filtration rate. Although many experimental animal studies regarding the role of IGF-1 in the kidney have been conducted, few human studies are available in the literature. Obesity is a cause of renal failure, and several glomerular lesions associated with obesity have been described. However, no studies regarding the levels of IGF-1 in morbidly obese patients with renal injury associated with obesity have been conducted.
To determine the serum IGF-1 concentrations in morbidly obese patients with normal renal function but with different types of early obesity-related glomerular lesions and to evaluate the possible relationship between IGF-1 and the presence of renal lesions.
Eighty morbidly obese patients with renal biopsy, including 11 patients with no evidence of renal lesion, 17 patients with single glomerulomegaly, 21 patients with single podocyte hypertrophy, 10 patients with glomerulomegaly and podocyte hypertrophy, 5 patients with focal segmental hyalinosis, and 16 patients with increased mesangial matrix and/or mesangial proliferation, participated in this study. Biological parameters, including serum IGF-1 concentrations with the standard deviation score for age (SDS-IGF-1), were determined for all patients.
Eighty patients (50 women and 30 men) with a mean BMI of 52.63 ± 8.71 and a mean age of 42.40 ± 9.45 years were included in this study. IGF-1, IGF-1 SDS and IGF-1BP3 levels according to the renal injury were compared (normal glomeruli: IGF-1 = 190.17 ± 72.46; glomerulomegaly: IGF-1 = 122.3 ± 50.05; podocyte hypertrophy: IGF-1 = 119.81 ± 60.34; focal segmental hyalinosis: IGF-1 170.98 ± 100.83, increased mesangial matrix and/or mesangial proliferation: IGF-1 117.73 ± 63.87). Statistically significant differences were observed between serum levels of IGF-1 and between the levels of SDS-IGF-1 by comparing the group without glomerular lesion with the group formed by patients with any type of glomerular injury. Logistic regression analysis was performed, with the dependent variable defined as the glomerular injury. In the multivariate analysis, only SDS-IGF-1 was associated with glomerular injury, and low levels of IGF-1 SDS were a risk factor for kidney injury.
Our study demonstrates that low IGF-1 serum levels are associated with renal lesions in morbidly obese patients without overt clinical renal manifestations.
胰岛素样生长因子-1（IGF-1）是一种参与细胞生长及其他重要过程的激素。在肾脏中，IGF-1具有刺激作用，可增加血流量和肾小球滤过率。尽管已经进行了许多关于IGF-1在肾脏中作用的实验动物研究，但文献中关于人类的研究却很少。肥胖是肾衰竭的一个原因，并且已经描述了几种与肥胖相关的肾小球病变。然而，尚未有关于肥胖相关肾损伤的病态肥胖患者中IGF-1水平的研究。
确定肾功能正常但患有不同类型早期肥胖相关肾小球病变的病态肥胖患者的血清IGF-1浓度，并评估IGF-1与肾脏病变存在之间的可能关系。
80例进行了肾活检的病态肥胖患者参与了本研究，其中11例无肾脏病变证据，17例有单个肾小球肿大，21例有单个足细胞肥大，10例有肾小球肿大和足细胞肥大，5例有局灶节段性玻璃样变，16例有系膜基质增加和/或系膜增生。测定了所有患者的生物学参数，包括血清IGF-1浓度及年龄标准差评分（SDS-IGF-1）。
本研究纳入了80例患者（50名女性和30名男性），平均体重指数为52.63±8.71，平均年龄为42.40±9.45岁。比较了根据肾损伤情况的IGF-1、IGF-1 SDS和IGF-1BP3水平（正常肾小球：IGF-1 = 190.17±72.46；肾小球肿大：IGF-1 = 122.3±50.05；足细胞肥大：IGF-1 = 119.81±60.34；局灶节段性玻璃样变：IGF-1 170.98±100.83，系膜基质增加和/或系膜增生：IGF-1 117.73±63.87）。通过比较无肾小球病变组与任何类型肾小球损伤患者组成的组，观察到血清IGF-1水平和SDS-IGF-1水平之间存在统计学显著差异。进行了逻辑回归分析，将因变量定义为肾小球损伤。在多变量分析中，只有SDS-IGF-1与肾小球损伤相关，低水平的IGF-1 SDS是肾损伤的一个危险因素。
我们的研究表明，血清IGF-1水平低与无明显临床肾脏表现的病态肥胖患者的肾脏病变相关。
