title: Undercarboxylated osteocalcin as a biomarker of subclinical atherosclerosis in non-dialysis patients with chronic kidney disease.
abstract: BACKGROUND
  Studies in recent years have shown that undercarboxylated osteocalcin (uOC) not only maintains bone mineralization, but is also involved in the regulation of atherosclerosis. However, a correlation between uOC and carotid atherosclerosis in non-dialysis patients with chronic kidney disease (CKD) has not been investigated. A total of 240 non-dialysis patients with CKD were included in the study. For these patients, the median estimated glomerular filtration rate (eGFR) was 20.05 (12.43-49.32) ml/min/1.73m(2). Serum uOC levels were measured using enzyme-linked immunosorbent assay (ELISA). Carotid ultrasonography was performed to assess carotid atherosclerotic plaques and intima-media thickness (IMT) in an attempt to analyze the relationship between uOC level and carotid atherosclerosis.
  
  
  RESULTS
  The uOC levels of non-dialysis patients with CKD were significantly lower than those of healthy controls [28.16 (21.40-45.85) ng/mL vs. 36.42 (28.05-49.28) ng/mL, P < 0.01]. The uOC levels gradually decreased as CKD progressed (P < 0.01). The uOC levels were significantly lower in patients with carotid plaques than in patients without carotid plaques [25.98 (20.14-31.35) ng/mL vs. 31.02 (25.86-36.40) ng/mL, P < 0.01]. uOC level showed significant negative correlation with IMT (r = -0.33, P < 0.01). Logistic regression analysis revealed that after adjustment for various confounding factors, decreased uOC levels were shown to indicate increased possibility of carotid atherosclerotic plaque development in non-dialysis patients with CKD (on every 1 SD decrease in the uOC level, odds ratio 1.70, 95 % confidence interval 1.24-2.98, P < 0.01). Multivariate stepwise regression analysis demonstrated that decreased uOC level (β = -0.163, P < 0.05) was an independent risk factor for increased carotid IMT in non-dialysis patients with CKD.
  
  
  CONCLUSIONS
  Serum uOC levels in non-dialysis patients with CKD are significantly lower than those in healthy individuals, and uOC is closely associated with subclinical atherosclerosis in CKD patients.
authors.affiliation: Renal Division, Renji Hospital, School of Medicine, Shanghai Jiaotong University, 160 Pujian Road, Shanghai, 200127, China. minfangzh@126.com.
authors.forename: Minfang
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Renal Division, Renji Hospital, School of Medicine, Shanghai Jiaotong University, 160 Pujian Road, Shanghai, 200127, China. prof_nizh@126.com.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Ni
authors.affiliation: Renal Division, Renji Hospital, School of Medicine, Shanghai Jiaotong University, 160 Pujian Road, Shanghai, 200127, China. zhouwenyan1217@126.com.
authors.forename: Wenyan
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Renal Division, Renji Hospital, School of Medicine, Shanghai Jiaotong University, 160 Pujian Road, Shanghai, 200127, China. profqian@163.com.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Qian
mesh_terms: D000368:Aged; D050197:Atherosclerosis / Q000097:blood* / Q000000981:diagnostic imaging / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D059168:Carotid Intima-Media Thickness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood*; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging
chemical_list: D015415:Biomarkers; D015675:Osteocalcin