Li Qiao, Feng Lie, Li Jiaying, Chen Qianqian
Department of Endocrinology, The First Affiliated Hospital, Jinan University, Huangpu Avenue West 613#, Guangzhou, 510632, China.
Endocrine. 2014 May;46(1):83-9. doi: 10.1007/s12020-013-0033-9. Epub 2013 Aug 13.
The aim of this study was to analyze urinary Smad1 level in patients with type 2 diabetes, explore the possibility of Smad1 being a biomarker for early diagnosis and evaluation of severity of diabetic nephropathy, and explore the impact factors affecting urinary Smad1 concentration. In this study, 132 subjects with type 2 diabetes and 50 healthy volunteers were enrolled. Subjects were grouped according to urine albumin to creatinine ratio (ACR) into: normal albumin in urine (NAU), low albumin in urine (LAU), high albumin in urine (HAU), and very high albumin in urine (VHAU). Among those, LAU, HAU, and VHAU were regarded as the diabetic nephropathy group (DN group), NAU was regarded as nondiabetic nephropathy (non-DN group), and the healthy volunteers were the controls. Enzyme-linked immunosorbent assay was used to detect the urinary Smad1 concentration, urinary Smad1 to creatinine ratio (SCR) was used as the standard reference. Compared with non-DN group, SCR of DN group was higher (P < 0.05), while there was no difference between the non-DN group and controls (P > 0.05). There was no significant difference for SCR between LAU and NAU groups (P > 0.05). The SCR was higher in VHAU group than those in HAU and LAU groups, and higher in HAU than that in LAU group (P < 0.05). Pearson correlation analysis showed that SCR measures were positively correlated to ACR, duration and diabetic retinopathy of the disease (r = 0.285, 0.230, 0.202; P = 0.001, 0.008, 0.019, respectively). Multiple linear regression analysis showed that ACR and duration were independent impact factors for SCR (P < 0.05). This is the first known study examining the correlation of Smad1 and DN in clinical practice. It suggested that the urinary Smad1 may be a potential diagnostic parameter for DN and may be used to evaluate the severity of DN. However, it cannot predict those in patients with the earliest DN and low urine albumin concentration. Furthermore, ACR and duration may be independent impact factors for urinary Smad1.
本研究旨在分析2型糖尿病患者尿Smad1水平，探讨Smad1作为糖尿病肾病早期诊断及病情严重程度评估生物标志物的可能性，并探究影响尿Smad1浓度的相关因素。本研究纳入了132例2型糖尿病患者和50名健康志愿者。根据尿白蛋白与肌酐比值（ACR）将研究对象分为：尿白蛋白正常（NAU）、尿白蛋白轻度升高（LAU）、尿白蛋白升高（HAU）和尿白蛋白显著升高（VHAU）。其中，LAU、HAU和VHAU组被视为糖尿病肾病组（DN组），NAU组被视为非糖尿病肾病组（非DN组），健康志愿者作为对照组。采用酶联免疫吸附测定法检测尿Smad1浓度，以尿Smad1与肌酐比值（SCR）作为标准参考指标。与非DN组相比，DN组的SCR更高（P<0.05），而非DN组与对照组之间无差异（P>0.05）。LAU组和NAU组之间的SCR无显著差异（P>0.05）。VHAU组的SCR高于HAU组和LAU组，HAU组的SCR高于LAU组（P<0.05）。Pearson相关分析显示，SCR与疾病的ACR、病程及糖尿病视网膜病变呈正相关（r分别为0.285、0.230、0.202；P分别为0.001、0.008、0.019）。多元线性回归分析显示，ACR和病程是SCR的独立影响因素（P<0.05）。这是临床实践中首个研究Smad1与DN相关性的已知研究。结果表明，尿Smad1可能是DN的潜在诊断参数，可用于评估DN的严重程度。然而，它无法预测早期DN且尿白蛋白浓度低的患者。此外，ACR和病程可能是尿Smad1的独立影响因素。
