title: Prepubertal Adiposity, Vitamin D Status, and Insulin Resistance.
abstract: To evaluate the following from prepuberty to the puberty-onset: (1) changes in serum 25-hydroxyvitamin-D (25[OH]D), adiposity, and insulin resistance (IR); (2) the effect of prepubertal adiposity on serum 25(OH)D changes; and (3) the combined effect of prepubertal obesity and suboptimal-25(OH)D on IR at puberty-onset.
  
  
  
  A total of 426 prepubertal children (∼54% girls) were followed during pubertal-onset assessing before and after puberty-onset serum 25(OH)D, adiposity (BMI and waist circumference) and IR indicators (homeostasis-model-assessment of IR [HOMA-IR]). Associations were tested using multiple and logistic regression models adjusted by age, gender, and seasonality.
  
  
  
  At puberty-onset, mean serum 25(OH)D decreased (32.2 ± 8.9 Tanner I vs 25.2 ± 8.3 ng/mL Tanner II) and total and central obesity increased (BMI-for-age-z-score ≥2 SD [%]: 16.4 vs 22.1; waist-circumference ≥75th percentile [%]: 27.2 vs 37.1, all P < .05). Children with higher adiposity before puberty onset had higher risk of suboptimal-25(OH)D (<30 ng/mL) in Tanner II (ie, odds ratio = 2.7 [1.1-6.7] for obesity and 2.7 [1.4-5.5] for central-obesity) after adjusting for relevant covariates. Children with higher adiposity and suboptimal-25(OH)D before puberty-onset had higher HOMA-IR compared with their counterparts in Tanner II (HOMA-IR: 2.8 [2.5-3.1] if central-obese and suboptimal-25[OH]D vs 2.1 [1.9-2.3] no central-obesity and optimal-25[OH]D).
  
  
  
  We found that serum 25(OH)D declined with puberty-onset, likely because of adiposity increase. Moreover, children with the combined condition of central-obesity and suboptimal-25(OH)D before puberty-onset had higher pubertal IR. These results highlight the need of ensuring adequate-25(OH)D status before pubertal-onset, particularly in obese children.
authors.affiliation: Institutes of Nutrition and Food Technology, and.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Cediel
authors.affiliation: Institutes of Nutrition and Food Technology, and ccorvalan@inta.uchile.cl.
authors.forename: Camila
authors.initials: C
authors.lastname: Corvalán
authors.affiliation: Institutes of Nutrition and Food Technology, and Nutrition Research Institute, Lima, Peru; and.
authors.forename: Daniel
authors.initials: D
authors.lastname: López de Romaña
authors.affiliation: Maternal and Child Research, Faculty of Medicine, University of Chile, Santiago, Chile;
authors.forename: Verónica
authors.initials: V
authors.lastname: Mericq
authors.affiliation: Institutes of Nutrition and Food Technology, and Department of Nutrition and Public Health Intervention Research, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Uauy
mesh_terms: D050154:Adiposity; D015992:Body Mass Index; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007333:Insulin Resistance; D008137:Longitudinal Studies; D008297:Male; D011627:Puberty / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D055105:Waist Circumference
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D