Level of education is associated with risk of kidney diseases in middle-aged and elderly adults: evidence from the CHARLS

Although numerous studies have indicated that various socioeconomic factors influence the risk of developing kidney disease, clinical evidence regarding the relationship between level of education (LoE) and the risk of kidney disease remains insufficient. This study aims to evaluate the association between LoE and the risk of kidney disease among middle-aged and elderly populations. This cross-sectional analysis utilized data from the 2020 wave of the China Health and Retirement Longitudinal Study (CHARLS), a nationally representative longitudinal panel survey. A total of 1,551 participants were included in this study after applying the exclusion criteria. The participants were categorized into three groups: primarily educated/uneducated (PE/UE), secondarily educated (SE), and highly educated (HE). Logistic regression and restricted cubic spline (RCS) regression were employed to develop the models. Participants in the SE group exhibited the highest risk of kidney disease (OR, 2.07; 95%CI, 1.09–3.94). In contrast, the risk decreased in the HE group (OR, 0.77; 95% CI, 0.29–2.02). Both crude and adjusted RCS models indicated a nonlinear association between LoE and the risk of kidney disease (P for nonlinear: 0.017 and 0.015, respectively). The risk peaked at approximately the SE level and gradually declined with subsequent increases in LoE. Our findings suggest that LoE and the risk of kidney disease demonstrate a nonlinear relationship, with SE representing the highest risk point. Pursuing higher education after completing SE appears to be associated with a reduced risk of developing kidney disease. This suggests that enhancing access to higher education could help alleviate the burden of kidney disease.