Predictors of coronary artery calcification and its association with cardiovascular events in patients with chronic kidney disease

Abstract

Objective: To investigate the predictors of coronary artery calcification (CAC) and its association with cardiovascular events (CVE) in patients with stage 3-5 chronic kidney disease (CKD).

Method: Two hundred ninety CKD patients in our nephrology department were enrolled from 2018 to May 2019. The levels of matrix Gla protein (MGP) and interleukin 6 (IL-6) were measured via enzyme-linked immunosorbent assay (ELISA) method in 131 CKD patients of all. CAC was evaluated via computed tomography (CT). The covariate factors were analyzed by binary logistic regression analysis. We conducted the visits to explore the prevalence of CVE in 276 CKD patients, and covariate factors were analyzed by Cox proportional hazard model.

Results: The prevalence of CAC was up to 57.93%. We found that age, diabetes mellitus, hyperphosphatemia, dialysis duration, and the neutrophil-lymphocyte ratio (NLR) were positively associated with CAC in all patients. In 131 patients, we demonstrated that higher IL-6 and lower MGP levels were associated with CAC. A Cox proportional hazard model demonstrated that moderate to severe CAC was correlated with an increased risk for CVE [Hazard Ratio (HR): 7.250; 95% confidence interval (CI): 3.192-16.470], and a higher MGP level was associated with a reduced risk for CVE (HR: 0.340; 95% CI: 0.124-0.933).

Conclusions: The prevalence of CAC in patients with CKD is a significant issue. Older age, hyperphosphatemia, dialysis duration, diabetes mellitus, IL-6, and the NLR are associated with CAC. In addition, higher MGP levels represent protective factor for CAC. Moderate to severe CAC, and lower MGP levels are associated with an increased risk for CVE. Abbreviations: AGEs: Advanced glycosylation end products; CAC: Coronary artery calcification; CACS: Coronary artery calcification score; Ca: Calcium; CI: confidence interval; CKD: Chronic kidney disease; CVE: Cardiovascular events; CT: Computed tomography; ELISA: Enzyme-linked immunosorbent assay; Hb: hemoglobin; HR: Hazard ratio; hs-CRP: high-sensitivity C-reactive protein; IL-6: Interleukin 6; iPTH: Intact parathyroid hormone; Mg: Magnesium; MGP: Matrix Gla protein; NF-κB: nuclear factor-kappa gene binding; NRL: Neutrophil-lymphocyte ratio; Runx2: Runt-related transcription factor 2; RRT: Renal replacement therapy; P: Phosphorus; Scr: Serum creatinine; TNF--alpha: Tumor necrosis factor--alpha; TC: Total cholesterol; TG: Triglyceride; VSMC: vascular smooth muscle cel.

Keywords: Chronic kidney disease; cardiovascular events; coronary artery calcification; matrix Gla protein; neutrophil-lymphocyte ratio.

Figure 1.

Kaplan–Meier curve for non-fatal cardiovascular events according to coronary artery calcification score; group with moderate to severe CAC (CACS ≥ 100), group with non-moderate to severe group (CACS<100).

Figure 2.

Kaplan–Meier curve for non-fatal cardiovascular events according to MGP levels; group with above-median MGP (MGP > 11.69 ng/ml), group with below-median MGP (MGP ≤ 11.69 ng/ml).