Relationship of Serum 25-Hydroxyvitamin D, Parathyroid Hormone with Insulin Resistance and the Impaired Fasting Glucose in Overweight or Obese Children and Adolescents

Abstract

Introduction: The nonclassical roles of vitamin D and parathyroid hormone (PTH) in glucose metabolism, insulin resistance, and metabolic syndrome have been proven with increasing evidence in the adult population. However, the role of PTH is controversial and pediatric studies are limited. Therefore, the aim of this study was to examine the association of 25-hydroxyvitamin D [25(OH)D] and PTH levels with insulin resistance, impaired fasting glucose, and metabolic syndrome. Methods: Obese and overweight children and adolescents that visited Seoul National University Childrens Hospital were enrolled. Correlations between 25(OH)D and PTH levels and HOMA-IR (Homeostasis Model Assessment–Insulin Resistance), fasting glucose, HbA1c, and metabolic syndrome were evaluated by linear regression and logistic regression analysis. Results: In overweight or obese children and adolescents, adjusting for sex, puberty, and body mass index (BMI) Z-score, 25(OH)D levels were related to HOMA-IR and fasting glucose, independent of PTH levels. PTH levels were related to fasting glucose, although this relationship was not independent of 25(OH)D levels. Conclusions: This study revealed a significant relationship between vitamin D with fasting glucose and insulin resistance. PTH was correlated with FBG, but this relationship between PTH and fasting glucose was not independent of 25(OH)D.