title: Concentrations of the vitamin D metabolite 1,25(OH)2D and odds of metabolic syndrome and its components.
abstract: OBJECTIVE
  Few epidemiological studies have investigated the association between circulating concentrations of the active vitamin D metabolite 1,25(OH)2D and metabolic syndrome. We sought to determine whether blood levels of 1,25(OH)2D are associated with metabolic syndrome and its individual components, including waist circumference, triglycerides, blood pressure, and glucose, and high-density lipoprotein. We also investigated these associations for the more abundant precursor vitamin D metabolite, 25(OH)D.
  
  
  METHODS
  Participants from two completed clinical trials of colorectal neoplasia with available metabolic syndrome data and blood samples for measurement of 1,25(OH)2D (n=1048) and 25(OH)D (n=2096) were included. Cross-sectional analyses of the association between concentrations of 1,25(OH)2D, 25(OH)D, metabolic syndrome, and its components were conducted.
  
  
  RESULTS
  A statistically significant inverse association was observed for circulating concentrations of 1,25(OH)2D and metabolic syndrome, with adjusted ORs (95% CIs) of 0.73 (0.52-1.04) and 0.52 (0.36-0.75) for the second and third tertiles of 1,25(OH)2D, respectively (p-trend <0.001). Significant inverse relationships were also observed between 1,25(OH)2D and high triglycerides (p-trend <0.001), and low high-density lipoprotein (p-trend <0.001). For 25(OH)D concentrations, significant inverse associations were found for metabolic syndrome (p-trend <0.01), high waist circumference (p-trend <0.04) and triglyceride levels (p-trend <0.01). Participants with 25(OH)D ≥30 ng/ml and in the highest tertile of 1,25(OH)2D demonstrated significantly lower odds of metabolic syndrome, with an OR (95% CI) of 0.38 (0.19-0.75) compared to those in the lowest category for both metabolites.
  
  
  CONCLUSIONS
  These results provide new evidence that the relatively rarely-studied active hormonal form of vitamin D, 1,25(OH)2D, is associated with metabolic syndrome and its components, and confirm prior findings for 25(OH)D. The finding that 1,25(OH)2D is related to high-density lipoprotein, while 25(OH)D is not, suggests that there may be an independent mechanism of action for 1,25(OH)2D in relation to metabolic dysregulation.
authors.affiliation: University of Arizona Cancer Center, 1515N. Campbell Avenue, Tucson, AZ 85724-5024, USA.
authors.forename: Jennifer W
authors.initials: JW
authors.lastname: Bea
authors.affiliation: School of Mathematical and Natural Sciences, Arizona State University, 4701W. Thunderbird Rd, Phoenix, AZ 85306, USA.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Jurutka
authors.affiliation: Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, 2220 Pierce Ave, Nashville, TN 37232, USA; Mel and Enid Zuckerman College of Public Health, 1295N. Martin Ave., Tucson, AZ, 85724, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Hibler
authors.affiliation: University of Arizona Cancer Center, 1515N. Campbell Avenue, Tucson, AZ 85724-5024, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Lance
authors.affiliation: UCSD Moores Cancer Center, 3855 Health Sciences Drive, La Jolla, CA 92093, USA.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Martínez
authors.affiliation: University of Arizona Cancer Center, 1515N. Campbell Avenue, Tucson, AZ 85724-5024, USA; Mel and Enid Zuckerman College of Public Health, 1295N. Martin Ave., Tucson, AZ, 85724, USA.
authors.forename: Denise J
authors.initials: DJ
authors.lastname: Roe
authors.affiliation: Mailman School of Public Health, Columbia University, 722W 168th St, New York, NY 10032, USA.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Sardo Molmenti
authors.affiliation: University of Arizona Cancer Center, 1515N. Campbell Avenue, Tucson, AZ 85724-5024, USA.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Thompson
authors.affiliation: University of Arizona Cancer Center, 1515N. Campbell Avenue, Tucson, AZ 85724-5024, USA; Mel and Enid Zuckerman College of Public Health, 1295N. Martin Ave., Tucson, AZ, 85724, USA. Electronic address: jacobse@email.arizona.edu.
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Jacobs
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000378:metabolism; D000368:Aged; D002117:Calcitriol / Q000097:blood*; D003430:Cross-Sectional Studies; D004032:Diet; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood*; D008875:Middle Aged; D012621:Seasons; D012737:Sex Factors; D012959:Socioeconomic Factors; D014808:Vitamin D Deficiency / Q000097:blood; D055105:Waist Circumference
chemical_list: D015652:25-Hydroxyvitamin D 2; D002117:Calcitriol
keywords: 1,25(OH)(2)D; 25(OH)D; Metabolic syndrome; Vitamin D