Genetic association analyses highlight apolipoprotein B as a determinant of chronic kidney disease in patients with type 2 diabetes.

Background: Blood lipid levels were associated with chronic kidney disease (CKD) in patients with type 2 diabetes (T2D), but the genetic basis and causal nature remain unclear.

Objective: This study aimed to investigate the relationships of lipids and their fractions with CKD in patients with T2D.

Methods: Our prospective analysis involved 8,607 White participants with T2D but no CKD at baseline from the UK Biobank. Five common lipid traits were included as exposures. Weighted genetic risk scores (GRSs) for these lipid traits were developed. The causal associations between lipid traits, as well as lipid fractions, and CKD were explored using linear or nonlinear Mendelian randomization (MR). The 10-year predicted probabilities of CKD were evaluated via integrating MR and Cox models.

Results: Higher GRS of apolipoprotein B (ApoB) was associated with an increased CKD risk (hazard ratio (HR) [95% confidence interval (CI)]:1.07[1.02,1.13] per SD; P = 0.008) after adjusting for potential confounders. Linear MR indicated a positive association between genetically predicted ApoB levels and CKD (HR [95% CI]:1.53 [1.12,2.09]; P = 0.008), but no evidence of associations was found between other lipid traits and CKD in T2D. Regarding 12 ApoB- containing lipid fractions, a significant causal association was found between medium very-low-density lipoprotein particles and CKD (HR[95% CI]:1.16[1.02,1.32];P = 0.020). Nonlinear MR did not support nonlinearity in these causal associations. The 10-year probability curve showed that ApoB level was positively associated with the risk of CKD in patients with T2D.

Conclusion: Lower ApoB levels were causally associated with a reduced risk of CKD in patients with T2D, positioning ApoB as a potential therapeutic target for CKD prevention in this population.