Effect of Lipid Abnormality on CKD Progression from Moderate to Severe Stage: Application of Flexible Parametric Proportional-Hazards and Proportional-Odds Models

Background: Lipid disorders are a well-documented risk factor for chronic kidney disease (CKD), but the impact of lipid abnormalities in the progression of the disease remains mixed. Objectives: The current study aimed to extend the existing knowledge about the effect of lipid disorders in disease progression from moderate to severe stage using Flexible parametric survival models. Methods: This retrospective cohort study included 308 moderate CKD patients who received the nephrologist follow-up visits at the nephrology clinic, Ilam (Iran), from 2012 to 2019. The survival time was determined based on the time medically diagnosed with moderate stages (GFR = 59 - 55 mL/min per 1.73m2) to the time of progression to the severe stage (GFR = 29 - 25 mL/min per 1.73m2) hazard using flexible parametric survival models. Results: In univariate analysis, high levels of TG, LDL, and cholesterol were important risk factors which affect the CKD progression. The hazard of patients with TG > 200 mg/dL was 1.69 times higher than patients with desirable TG levels (P = 0.09). Moreover, for patients with LDL > 160 mg/dL, the hazard was 2.12 times higher than patients with desirable LDL levels (P = 0.01). The hazard of patients with total cholesterol levels > 240 mg/dL was 2.10 times higher than patients with desirable cholesterol levels (P = 0.003). The adjusted model was shown to better fit the PH model. Cholesterol levels > 240 mg/dL remains a significant risk factor for CKD progression (P = 0.03). Conclusions: Effective treatment programs should pay closer attention to screening and treatment of hyperlipidemia in patients diagnosed with moderate CKD.