title: Hypovitaminosis D associations with adverse metabolic parameters are accentuated in patients with Type 2 diabetes mellitus: a body mass index-independent role of adiponectin?
abstract: BACKGROUND
  Hypovitaminosis D has been associated with an increased prevalence of Type 2 diabetes mellitus (DMT2) and metabolic syndrome manifestations. The purpose of this study was to examine the association between 25-hydroxy-vitamin D (25-OH-VitD) levels and indices of insulin resistance (IR), including adipocytokines, in a Saudi population with or without DMT2.
  
  
  METHODS
  A total of 266 subjects (153 DMT2 and 113 healthy controls) aged 26-80 yr were randomly selected from the existing Biomarkers Screening in Riyadh Program (RIYADH Cohort). Subjects were assessed clinically, anthropometry was performed, morning blood chemistries, including fasting glucose (FG), triglycerides, total cholesterol, LDL cholesterol (LDL-C), and HDL cholesterol were obtained. Homeostasis model assessment of IR (HOMA-IR) was calculated, and serum 25-OH-VitD, leptin, adiponectin, resistin, insulin, high sensitivity CRP (hsCRP), and tumor necrosis factor α concentrations were measured using specific assays.
  
  
  RESULTS
  In DMT2 subjects, negative correlations between 25-OH-vitD and body mass index (BMI), FG, insulin, HOMA-IR, cholesterol, LDL-C, and hsCRP were observed, while a positive correlation between 25-OH-VitD and adiponectin was detected. The later remained significant after controlling for BMI. Interestingly, only weak and nonsignificant associations between 25-OH-VitD and metabolic parameters were observed in the control group, whereas, when the entire population was examined, negative correlations were evident primarily between 25-OH-VitD and FG, HOMA-IR, total cholesterol, LDL-C. These associations remained significant after controlling for BMI.
  
  
  CONCLUSIONS
  These results suggest that hypovitaminosis D associations with metabolic disturbances are accentuated in DMT2. The BMIindependent positive correlation between 25-OH-VitD and adiponectin suggests a potential role for this adipocytokine as a link between 25-OH-VitD and IR in patients with DMT2.
authors.affiliation: Biomarkers Research Program, Biochemistry Department, College of Science, King Saud University, Riyadh, KSA. ndaghri@KSU.EDU.SA
authors.forename: N M
authors.initials: NM
authors.lastname: Al-Daghri
authors.forename: O S
authors.initials: OS
authors.lastname: Al-Attas
authors.forename: M S
authors.initials: MS
authors.lastname: Alokail
authors.forename: K M
authors.initials: KM
authors.lastname: Alkharfy
authors.forename: A
authors.initials: A
authors.lastname: Al-Othman
authors.forename: H M
authors.initials: HM
authors.lastname: Draz
authors.forename: S M
authors.initials: SM
authors.lastname: Yakout
authors.forename: Y
authors.initials: Y
authors.lastname: Al-Saleh
authors.forename: M
authors.initials: M
authors.lastname: Al-Yousef
authors.forename: S
authors.initials: S
authors.lastname: Sabico
authors.forename: M
authors.initials: M
authors.lastname: Clerici
authors.forename: G P
authors.initials: GP
authors.lastname: Chrousos
mesh_terms: D054392:Adipokines / Q000097:blood; D052242:Adiponectin / Q000097:blood*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000209:etiology*; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D020738:Leptin / Q000097:blood; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications*; D055815:Young Adult
chemical_list: D054392:Adipokines; D052242:Adiponectin; D007328:Insulin; D020738:Leptin; D014807:Vitamin D