title: Association between serum 25-hydroxyvitamin D levels and carotid atherosclerosis in chronic kidney disease patients.
abstract: Epidemiological studies have shown an inverse relationship between vitamin D levels and cardiovascular diseases. However, this does not infer a causal relationship between the two. Chronic kidney disease (CKD) patients have a high prevalence of vitamin D deficiency and carotid atherosclerosis. Therefore, in this study we have aimed to determine the association between serum 25-hydroxyvitamin D levels and carotid atherosclerosis in the CKD population.
  
  
  
  100 CKD stage 3-4 patients were included in the study. Direct chemiluminesent immunoassay was used to determine the level of serum 25-hydroxyvitamin D. All subjects underwent a carotid ultrasound to measure common carotid artery intima-media thickness (CCA-IMT) and to assess the presence of carotid plaques or significant stenosis (≥50 %). Vitamin D deficiency was defined as serum 25-hydroxyvitamin D < 25 nmol/L. Abnormal CCA-IMT was defined as CCA-IMT ≥ 0.8 mm. Plaque was defined as a focal structure that encroaches into the arterial lumen of ≥ 0.5 mm or 50 % of the surrounding IMT value. Significant stenosis was defined as peak-systolic velocities ≥ 125 cm/s and end-diastolic velocities ≥ 40 cm/s.
  
  
  
  The vitamin D deficiency and non-deficiency groups did not differ significantly in terms of abnormal CCA-IMT (P = 0.443), carotid plaque (P = 0.349), and carotid stenosis (P = 0.554). No significant correlation between serum 25-hydroxyvitamin D levels and CCA-IMT (P = 0.693) was found. On a backward multiple linear regression model, serum 25-hydroxyvitamin D levels was not associated with CCA-IMT, abnormal CCA-IMT, or plaque presence.
  
  
  
  No important association between serum 25-hydroxyvitamin levels and carotid atherosclerosis was found in CKD patients.
authors.affiliation: Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Yong-Muh
authors.identifier: 0000-0002-0164-396X
authors.initials: YM
authors.lastname: Ng
authors.affiliation: Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Soo-Kun
authors.initials: SK
authors.lastname: Lim
authors.affiliation: Department of Family Medicine, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Pei-San
authors.initials: PS
authors.lastname: Kang
authors.affiliation: Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Khairul Azmi Abdul
authors.initials: KA
authors.lastname: Kadir
authors.affiliation: Division of Neurology, Department of Medicine, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia. sharont1990@gmail.com.
authors.forename: Mei-Ling Sharon
authors.initials: MS
authors.lastname: Tai
mesh_terms: D000368:Aged; D050197:Atherosclerosis / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging; D002340:Carotid Artery Diseases / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging; D059168:Carotid Intima-Media Thickness; D016893:Carotid Stenosis / Q000097:blood / Q000000981:diagnostic imaging / Q000209:etiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000150:complications
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Carotid atherosclerosis; Carotid intima-media thickness; Carotid plaque; Chronic kidney disease; Parathyroid hormone; Vitamin D