Consumption of ultraprocessed food and development of chronic kidney disease: the Tianjin Chronic Low-Grade Systemic Inflammation and Health and UK Biobank Cohort Studies

Many ultraprocessed food (UPF)-derived by-products may play a role in the development of chronic kidney disease (CKD). Although several studies have assessed the association of UPFs with kidney function decline or CKD in various countries, no evidence has been shown in China and the United Kingdom. This study aims to evaluate the association between UPF consumption and risk of CKD in 2 large cohort studies from China and the United Kingdom. In total, 23,775 and 102,332 participants without baseline CKD were enrolled in the Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) and UK Biobank cohort studies, respectively. Information on UPF consumption was obtained from a validated food frequency questionnaire in the TCLSIH and 24-h dietary recalls in the UK Biobank cohort. CKD was defined as an estimated glomerular filtration rate of <60 mL/min/1.73 m2, albumin-to-creatinine ratio ≥30 mg/g, or as having a clinical diagnosis of CKD in both cohorts. Multivariable Cox proportional hazard models were used to examine the association between UPF consumption and the risk of CKD. After a median follow-up of 4.0 and 10.1 y, the incidence rates of CKD were around 1.1% and 1.7% in the TCLSIH and UK Biobank cohorts, respectively. The multivariable hazard ratio [95% confidence interval] of CKD across increasing quartiles (quartiles 1–4) of UPF consumption were 1 (reference), 1.24 (0.89, 1.72), 1.30 (0.91, 1.87), and 1.58 (1.07, 2.34) (P for trend = 0.02) in the TCLSIH cohort and 1 (reference), 1.14 (1.00, 1.31), 1.16 (1.01, 1.33), and 1.25 (1.09, 1.43) (P for trend < 0.01) in the UK Biobank cohort, respectively. Our finding indicated that higher UPF consumption is associated with a higher risk of CKD. Moreover, restricting UPF consumption may potentially benefit the prevention of CKD. Further clinical trials are required to clarify the causality. This trial was registered at UMIN Clinical Trials Registry as UMIN000027174 (https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000031137).