THYROID FUNCTION AND GHRELIN AND LEPTIN LEVELS IN OBESE CHILDREN AND ADOLESCENTS WITH AND WITHOUT INSULIN RESISTANCE
INTRODUCTION: Thyroid hormones ghrelin, leptin, and insulin are implicated in energy metabolism.
OBJECTIVE: The objective of this study was to investigate any relationship between thyroid function and ghrelin and leptin levels in selected euthyroid (thyrotropin: 0.35–4.94; free thyroxine [fT4]: 0.8–1.8; no autoimmune thyroiditis or iodine deficiency, no medications intake) obese children and adolescents with and without insulin resistance (IR).
METHODS: Forty obese children and 40 obese adolescents were enrolled. BMI, percentage of body fat, fasting glucose, insulin, ghrelin, leptin, thyrotropin, free triiodothyronine (fT3), and fT4 were measured. IR was estimated with homeostasis model assessment of IR index. The Mann-Whitney U test for independent samples was applied. Correlations were assessed by the Spearman coefficient.
RESULTS: In adolescents, fT3 levels were positively correlated with insulin and homeostasis model assessment of IR. In children, fT4 levels were negatively correlated with BMI and percentage of body fat (Table 1).
CONCLUSIONS: The observed positive correlation between IR and fT3 in adolescents might indicate an interplay between thyroid function and IR. Ghrelin levels are negatively affected by IR but not directly associated with thyroid hormone concentrations.
Submitted by Charilaos Stylianou
- Copyright © 2008 by the American Academy of Pediatrics