[Risk factors for coronary artery calcification in patients with end-stage renal disease]

To explore risk factors for coronary artery calcification (CAC) inpatients with end-stage renal disease (ESRD).

A total of 53 ESRD patients undergoing regular hemodialysis (3 times a week) from August 2014 to March 2015 in the Fourth Hospital of Hebei Medical University were enrolled in the study. The patients were divided into the negative control group (13 cases) and three positive groups (11 mild calcification cases, 12 moderate calcification cases and 17 severe calcification cases) based on coronary artery calcification score (CACs). Clinical data of all patients at study entry were collected. Arterial blood samples were also collected at the start of the first hemodialysis (HD) session of the week to measure the levels of serum albumin, uric acid, calcium (Ca), phosphorus (P), magnesium, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), C reactive protein (CRP), beta-2 microglobulin (β2-MG), free parathyroid hormone (iPTH), alkaline phosphatase, fibrinogen, hemoglobin (HGB) and ferritin. Meanwhile, levels of blood pH were detected after collecting pre- and post-HD blood samples to calculate ΔpH (post-HD pH subtracted pre-HD pH). Logistic regression analysis was performed to analyze the correlation of CACs with clinical data and previously-reported blood biochemical indicators, followed by analysis of the incidence of CAC and influential factors in ESRD patients.

Severity of CAC was positively correlated with age (r=0.269), HD duration (r=0.341), serum calcium (r=0.358), serum phosphorus (r=0.186) and pre-HD pH (r=0.275), but negatively correlated with serum albumin (r=-0.192) and ΔpH (r=-0.302), all P<0.05. Logistic regression analysis revealed that age, HD duration, serum phosphorus level and ΔpH were independent risk factors for CAC in ESRD patients (P<0.05). In CAC positive groups, CAC was predominantly involved in the left anterior descending artery (P<0.05, P<0.01 and P<0.01 in mild, moderate and severe calcification group, respectively).

CAC in ESRD patients seems to be affected by multiple factors, such as age, HD duration, serum phosphorus level and ΔpH. Moreover, ΔpH affects CAC mainly by pre-HD pH. Furthermore, left anterior descending artery is predominantly affected by CAC in ESRD patients.