Clinicopathological Characteristics and Prognostic Value of Dyslipidemia in IgA Nephropathy: A Retrospective Cohort Study

Background Dyslipidemia is common in chronic kidney disease (CKD) including IgA nephropathy (IgAN) and possibly associated with renal prognosis, but the value of dyslipidemia in IgAN remains insufficiently assessed. The objective of our study was to investigate clinicopathological characteristics and renal outcome in IgAN patients with dyslipidemia, and evaluate prognostic value of lipid abnormality. Methods This cohort study included 458 primary IgAN patients for a retrospective analysis. The clinicopathological features and renal outcome were recorded. In univariate and multivariate models, association between dyslipidemia and renal outcome, and dyslipidemia-associated pathological features were analyzed. Results Patients with dyslipidemia (defined as total cholesterol ≥ 5.2mmol/L, triglycerides ≥ 1.7mmol/L, or LDL-C ≥ 3.4mmol/L) presented elevated complement, and worse clinical characteristics with regard to blood pressure, proteinuria and kidney function, and glomerulosclerosis, tubular atrophy/interstitial fibrosis (T1-2), crescents, and vascular lesions were more common. By multivariate logistic regression, T1-2 and arterial intimal fibrosis were significantly associated with dyslipidemia. After a mean follow-up of 54.7 months, dyslipidemia (P = 0.001), especially abnormalities in total cholesterol (P = 0.016) and triglycerides (P = 0.001), was significantly associated with poorer renal survival, and renal survival was worse after lipid-lowering therapies. In addition to eGFR and arterial intimal fibrosis, dyslipidemia was an independent predictor for renal survival in multivariate Cox analyses (model 1: HR = 2.229, 95% CI = 1.146–4.336, P = 0.018; model 2: HR = 2.117, 95% CI = 1.082–4.145, P = 0.029). Conclusions IgAN patients with dyslipidemia presented more severe clinicopathological features. Tubular atrophy/interstitial fibrosis and arterio-/arteriolosclerosis were closely associated with dyslipidemia. Dyslipidemia not only indicated adverse renal outcomes, but also was an independent prognostic predictor.