title: Vitamin D levels, insulin resistance, and cardiovascular risks in very young obese children.
abstract: OBJECTIVE
  To examine the relationships of 25-hydroxyvitamin D (25-OHD) levels with the measures of insulin resistance and cardiovascular risk, and identify the clinical factors associated with low 25-OHD in young obese children.
  
  
  METHODS
  Data from 83 children ages 2-6 years seen for obesity care (clinic latitude 42°N) were analyzed. Insulin resistance [homeostasis model assessment of insulin resistance (HOMA-IR)] and cardiovascular risks were examined in relationship to 25-OHD levels using correlation statistics. χ2 and logistic regression models were applied to identify the factors associated with vitamin D deficiency (25-OHD levels <20 ng/mL) and insufficiency (<30 ng/mL).
  
  
  RESULTS
  Children's mean age was mean 4.9 years and they were predominantly Hispanic. Mean body mass index (BMI) Z-score was 3.2 and mean HOMA-IR was 2.8. Mean 25-OHD was 30.9 ng/mL (6% <20 ng/mL and 46% 20-29 ng/mL). There were no significant correlations between 25-OHD and BMI (Spearman's ρ=-0.096, p=0.389), BMI Z-score (Spearman's ρ=0.104, p=0.350), HOMA-IR (Spearman's ρ=-0.144, p=0.269), total cholesterol (Spearman's ρ=-0.028, p=0.833), or triglycerides (Spearman's ρ=-0.026, p=0.846). Vitamin D deficiency was significantly associated with older age, lower milk intake, and testing in winter months. 25-OHD level <30 ng/mL was associated with older age, African-American and Hispanic race/ethnicity, and testing in winter months. All factors retained significance in a multivariate logistic regression model, with African-American (odds ratio=14.4) and Hispanic (odds ratio=7.2) race/ethnicity being the strongest predictors of 25-OHD levels <30 ng/mL.
  
  
  CONCLUSIONS
  In these children, 25-OHD was not associated with insulin resistance or cardiovascular risks. Considering age, race/ethnicity, diet, and season may help identify young obese children needing vitamin D management.
authors: Department of Pediatrics, Mayo Eugenio Litta Children's Hospital, Rochester, MN, USA.
authors: Ana L
authors: AL
authors: Creo
authors: Joshua S
authors: JS
authors: Rosen
authors: Adolfo J
authors: AJ
authors: Ariza
authors: Katherine M
authors: KM
authors: Hidaka
authors: Helen J
authors: HJ
authors: Binns
mesh_terms: D017668:Age of Onset; D001786:Blood Glucose / Q000032:analysis; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D008055:Lipids / Q000097:blood; D008297:Male; D009765:Obesity / Q000097:blood / Q000453:epidemiology* / Q000378:metabolism; D012307:Risk Factors; D014807:Vitamin D / Q000097:blood*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D014807:Vitamin D