title: The relationship between 25-hydroxyvitamin D levels and ambulatory arterial stiffness index in newly diagnosed and never-treated hypertensive patients.
abstract: OBJECTIVE
  Vitamin D insufficiency has been shown to be associated with cardiac dysfunctions, such as cardiac hypertrophy and hypertension, in animal studies. Arterial stiffness is a prognostic marker for cardiovascular disease. Previous studies have demonstrated that 25-hydroxyvitamin D [25(OH)D] levels were negatively correlated with arterial stiffness index. The aim of this study was to investigate the relationship between 25(OH)D levels and arterial stiffness, which is evaluated using an ambulatory arterial stiffness index (AASI), in patients who have untreated and newly diagnosed essential hypertension.
  
  
  METHODS
  A total of 123 consecutive patients with newly diagnosed and untreated essential hypertension were included. Patients were divided into two groups according to their 25(OH)D levels. Vitamin D insufficiency was defined by 25(OH)D levels less than 20 ng/ml. All patients were referred for ambulatory blood pressure monitoring. The regression slope of diastolic and systolic blood pressure was computed for each individual on the basis of ambulatory blood pressure readings. AASI was described as one minus the respective regression slope.
  
  
  RESULTS
  The mean AASI was significantly higher in patients with 25(OH)D levels less than 20 as compared with patients with 25(OH)D levels greater than or equal to 20 (0.50±0.20 vs. 0.34±0.17, P<0.001). In Pearson's correlation analysis, AASI had a significantly strong negative correlation with vitamin D levels (r=-0.385, P<0.001). In multivariate linear regression analysis, vitamin D levels were found to be significantly and independently associated with AASI (β=-0.317, P=0.035).
  
  
  CONCLUSIONS
  Arterial stiffness measured by AASI in newly diagnosed and untreated patients with essential hypertension were significantly related to vitamin D levels.
authors.affiliation: Departments of aCardiology bNephrology cNeurology, Turgut Özal University Faculty of Medicine dDepartment of Internal Medicine, Section of Nephrology, Ankara Oncology Training and Research Hospital, Ankara, Turkey.
authors.forename: Özgül
authors.initials: Ö
authors.lastname: Malçok Gürel
authors.forename: Ayşe
authors.initials: A
authors.lastname: Bilgiç
authors.forename: Bora
authors.initials: B
authors.lastname: Demirçelik
authors.forename: Meltem
authors.initials: M
authors.lastname: Özaydin
authors.forename: Fadime
authors.initials: F
authors.lastname: Bozduman
authors.forename: Zübeyde
authors.initials: Z
authors.lastname: Aytürk
authors.forename: Hakki
authors.initials: H
authors.lastname: Yilmaz
authors.forename: Asli
authors.initials: A
authors.lastname: Atar
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Selçoki
authors.forename: Beyhan
authors.initials: B
authors.lastname: Eryonucu
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D000075222:Essential Hypertension; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000503:physiopathology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D059289:Vascular Stiffness; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D