Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Department of Epidemiology, Radboud University Medical Center, Nijmegen, The Netherlands.
Nephrol Dial Transplant. 2020 Jul 1;35(7):1211-1218. doi: 10.1093/ndt/gfy361.
The longitudinal association between low education and chronic kidney disease (CKD) and its underlying mechanisms is poorly characterized. We therefore examined the association of low education with incident CKD and change in kidney function, and explored potential mediators of this association.
We analysed data on 6078 participants from the community-based Prevention of Renal and Vascular End-stage Disease study. Educational level was categorized into low, medium and high (< secondary, secondary/equivalent, > secondary schooling, respectively). Kidney function was assessed by estimating glomerular filtration rate (eGFR) by serum creatinine and cystatin C at five examinations during ∼11 years of follow-up. Incident CKD was defined as new-onset eGFR <60 mL/min/1.73 m2 and/or urinary albumin ≥30 mg/24 h in those free of CKD at baseline. We estimated main effects with Cox regression and linear mixed models. In exploratory causal mediation analyses, we examined mediation by several potential risk factors.
Incident CKD was observed in 861 (17%) participants. Lower education was associated with higher rates of incident CKD [low versus high education; hazard ratio (HR) (95% CI) 1.25 (1.05-1.48), Ptrend = 0.009] and accelerated eGFR decline [B (95% CI) -0.15 (-0.21 to -0.09) mL/min/1.73 m2/year, Ptrend < 0.001]. The association between education and incident CKD was mediated by smoking, potassium excretion, body mass index (BMI), waist-to-hip ratio (WHR) and hypertension. Analysis on annual eGFR change in addition suggested mediation by magnesium excretion, protein intake and diabetes.
In the general population, we observed an inverse association of educational level with CKD. Diabetes and the modifiable risk factors smoking, poor diet, BMI, WHR and hypertension are suggested to underlie this association. These findings provide support for targeted preventive policies to reduce socioeconomic disparities in kidney disease.
低教育水平与慢性肾脏病（CKD）之间的纵向关联及其潜在机制尚未得到充分描述。因此，我们研究了低教育水平与 CKD 发病风险和肾功能变化之间的关联，并探讨了这种关联的潜在中介因素。
我们对基于社区的预防肾脏和血管终末期疾病研究中的 6078 名参与者进行了数据分析。教育水平分为低、中、高（分别为<中等教育、中等教育/同等学历、>中等教育）。在大约 11 年的随访期间，通过血清肌酐和胱抑素 C 估计肾小球滤过率（eGFR）来评估肾功能。CKD 新发病例定义为基线时无 CKD 的患者 eGFR<60 mL/min/1.73 m2和/或尿白蛋白≥30 mg/24 h。我们使用 Cox 回归和线性混合模型估计主要效应。在探索性因果中介分析中，我们检验了几个潜在风险因素的中介作用。
861 名（17%）参与者发生 CKD。较低的教育程度与较高的 CKD 发病风险相关[低教育程度与高教育程度相比；风险比（HR）（95%可信区间）1.25（1.05-1.48），Ptrend=0.009]和 eGFR 下降速度加快[B（95%可信区间）-0.15（-0.21 至-0.09）mL/min/1.73 m2/年，Ptrend<0.001]。教育程度与 CKD 发病风险之间的关联是通过吸烟、钾排泄、体重指数（BMI）、腰臀比（WHR）和高血压来介导的。对年度 eGFR 变化的分析还表明，镁排泄、蛋白质摄入和糖尿病也存在中介作用。
在一般人群中，我们观察到教育水平与 CKD 呈负相关。糖尿病以及可改变的危险因素如吸烟、不良饮食、BMI、WHR 和高血压可能是这种关联的基础。这些发现为针对减少肾脏疾病中社会经济差异的目标预防政策提供了支持。
