title: Low vitamin D is associated with hypertension in paediatric obesity.
abstract: OBJECTIVE
  The aim of this paper was to investigate the relationship between circulating 25-hydroxyvitamin D (25(OH)D) and cardio-metabolic risk factors in a large cohort of obese youth attending tertiary paediatric obesity services.
  
  
  METHODS
  We conducted a retrospective cross-sectional study. Data were retrospectively collected from all new consultations of children and adolescents attending obesity outpatient clinics between 2008 and 2011 at the two major paediatric hospitals in Melbourne, Australia. Information collected included demographics, anthropometry, blood pressure, pubertal staging, body composition and fasting serum levels of 25(OH)D, glucose, insulin, cholesterol, triglyceride, high-density lipoprotein, liver function, calcium and phosphate.
  
  
  RESULTS
  25(OH)D data were available in 229 patients (age 3-18 years; 116 men; mean (standard deviation) body mass index ( BMI) Z-score 2.5 (0.5) ). One hundred four (45%) participants were 25(OH)D deficient (<50 nmol/L). Lower serum 25(OH)D levels were associated with higher BMI Z-score (P-trend = 0.001), total fat mass (P-trend = 0.009), systolic (P-trend = 0.03) and diastolic blood pressures(P-trend = 0.009). In multivariable-adjusted regression analysis, 25(OH)D was significantly lower in those with elevated blood pressure after adjustment for BMI(P-trend = 0.004) or total fat mass (P-trend = 0.01).
  
  
  CONCLUSIONS
  Overweight and obese youth attending specialist obesity services have a high prevalence of vitamin D deficiency. In this population, lower levels of vitamin D were seen in those with greater adiposity, and independent of this, in those who had higher blood pressure.
authors.affiliation: Department of Endocrinology and Diabetes, The Royal Children's Hospital, Melbourne, Victoria, Australia.|Center for Hormone Research, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.|Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Kung-Ting
authors.initials: KT
authors.lastname: Kao
authors.affiliation: Department of Paediatrics, Monash University, Melbourne, Victoria, Australia.
authors.forename: Nobia
authors.initials: N
authors.lastname: Abidi
authors.affiliation: School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: Sanjeeva
authors.initials: S
authors.lastname: Ranasinha
authors.affiliation: Department of Paediatrics, Monash University, Melbourne, Victoria, Australia.|Department of Paediatric Endocrinology and Diabetes, Monash Children's Hospital, Melbourne, Victoria, Australia.
authors.forename: Justin
authors.initials: J
authors.lastname: Brown
authors.affiliation: Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.|Department of Paediatrics, Monash University, Melbourne, Victoria, Australia.|Western Centre for Health Research, Sunshine Hospital, Melbourne, Victoria, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Rodda
authors.affiliation: Department of Endocrinology and Diabetes, The Royal Children's Hospital, Melbourne, Victoria, Australia.|Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Zoe
authors.initials: Z
authors.lastname: McCallum
authors.affiliation: Department of Endocrinology and Diabetes, The Royal Children's Hospital, Melbourne, Victoria, Australia.|Center for Hormone Research, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.|Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Margaret
authors.initials: M
authors.lastname: Zacharin
authors.affiliation: Department of Endocrinology and Diabetes, The Royal Children's Hospital, Melbourne, Victoria, Australia.|Center for Hormone Research, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.|Department of Paediatric Endocrinology and Diabetes, Monash Children's Hospital, Melbourne, Victoria, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Simm
authors.affiliation: Menzies Research Institute, University of Tasmania, Hobart, Tasmania, Australia.|Research Centre of Applied and Preventative Cardiovascular Medicine, University of Turku, Turku, Finland.
authors.forename: Costan G
authors.initials: CG
authors.lastname: Magnussen
authors.affiliation: Department of Endocrinology and Diabetes, The Royal Children's Hospital, Melbourne, Victoria, Australia.|Center for Hormone Research, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.|Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.|Department of Paediatrics, Monash University, Melbourne, Victoria, Australia.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Sabin
mesh_terms: D000293:Adolescent; D001315:Australia / Q000453:epidemiology; D001794:Blood Pressure; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000453:epidemiology*; D008297:Male; D063766:Pediatric Obesity / Q000097:blood / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: children; hypertension; metabolic syndrome; obesity; vitamin D