Table of Contents Author Guidelines Submit a Manuscript
Journal of Obesity
Volume 2011, Article ID 495101, 7 pages
http://dx.doi.org/10.1155/2011/495101
Research Article

Vitamin D Deficiency in Obese Children and Its Relationship to Insulin Resistance and Adipokines

1Division of Endocrinology, Seattle Children's Research Institute, 1900 Ninth Avenue, Seattle, WA 98101, USA
2Department of Pediatrics Bonn, University of Bonn, Germany
3Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
4Department of Medicine, University of Washington, Seattle, WA 98195, USA
5Department of Epidemiology, University of Washington, Seattle, WA 98195, USA
6Department of Laboratory Medicine, University of Washington, Seattle, WA 98195, USA

Received 10 August 2011; Accepted 17 September 2011

Academic Editor: P. Trayhurn

Copyright © 2011 Christian L. Roth et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Low-serum concentrations of 25-hydroxyvitamin D [25(OH)D] are associated with insulin resistance in adults. Less data are available in pediatric populations. Serum 25(OH)D serum concentrations were assessed in 125 obese and 31 nonobese children (age  y, range 6–16 y, 49% male) living in Bonn, Germany. The relationship between 25(OH)D, measured by liquid chromatography-tandem mass spectrometry, and measures of insulin sensitivity and adipokines adiponectin and resistin were analyzed. Seventy-six % of subjects were 25(OH)D deficient (<20 ng/mL). Higher insulin, homeostasis model assessment-insulin resistance (HOMA-IR , ), and hemoglobin A1c ( ) as well as lower quantitative insulin-sensitivity check index (QUICKI , ) values were found in obese children with lower 25(OH)D concentrations even after adjustment for gender, age, and body mass index. Furthermore, 25(OH)D correlated significantly with adiponectin, but not with resistin. Our results suggest that hypovitaminosis D is a risk factor for developing insulin resistance independent of adiposity.