Prevalence of Vascular Calcification in Chronic Kidney Disease Stage 4 and 5 Patients and its Correlation with Inflammatory Markers of Atherosclerosis

Vascular calcification is one of the independent risk factors associated with cardiovascular disease (CVD) in chronic kidney disease (CKD) patients. This study evaluated the prevalence of vascular calcification in Indian patients with CKD stages 4 and 5. This was a prospective study conducted between January 2011 and June 2012. CKD stage 4 and 5 patients of either sex aged >18 years were screened for aortic vascular calcification using digital X-ray lumbar spine and multislice computed tomography (CT) scan. In addition, details of inflammatory markers [high-sensitivity C-reactive protein (hs-CRP) and interleukin (IL-6)] were also collected. A total of 150 patients (stage 4, n = 98; stage 5, n = 56) were screened for vascular calcification, and the mean age was 56.56 years. Patients with CKD stage 5 had significantly higher (P <= 0.05) serum creatinine and lower estimated glomerular filtration rate, total cholesterol, and low-density lipoprotein than CKD stage 4. Significantly, more patients with CKD stage 5 had a history of CVD. A total of 113 (75.3%) patients had vascular calcification [aortic calcification index (ACI) >0] with significantly higher prevalence in CKD stage 5 (85.72%) as compared to CKD stage 4 (69.15%). Patients having high aortic calcification (ACI >20%) were older (P = 0.0013); had a higher frequency of diabetes, and CVD; and had significantly (P <0.05) higher blood urea, serum creatinine, phosphorus, Ca x PO4 product, intact parathyroid hormone, hs-CRP, and IL-6. The higher CKD stage was associated with a higher prevalence of vascular calcification and higher aortic calcification index (ACI). CT techniques (electron beam CT and multislice CT) are the gold standards for detection and quantification of progression of vascular calcification.