Relationship between plasma leptin, insulin and tumor necrosis factor alpha in obese children

Objectives: 1. To evaluate the relationship between plasma leptin and TNF alpha concentrations in obese children and to assess the differences between hyperinsulinemic and normoinsulinemic groups. 2. To evaluate the relationship between plasma leptin and insulin levels in obese children. 3. To investigate the TNF alpha G308A mutation in obese children. Methods: Body mass index (BMI), fasting plasma glucose and insulin levels, oral glucose tolerance test results, homeostasis model assessment of insulin resistance (HOMA-IR) results, and plasma leptin and TNF alpha concentrations were evaluated in obese children (n = 45) and age- and gender-matched, lean healthy controls (n = 40). Results: In obese children the fasting insulin, HOMA-IR results, plasma leptin and TNF alpha concentrations were significantly higher than in controls (p < 0.05). Furthermore, obese females showed higher plasma leptin and insulin resistance compared to obese males. While plasma leptin, TNF alpha levels and HOMA-IR results were similar in the prepubertal and pubertal groups, insulin levels were significantly higher in the pubertal group. Plasma leptin and TNF alpha concentrations were similar in hyperinsulinemic and normoinsulinemic obese children. In control children, plasma leptin concentrations showed a positive correlation with BMI, age, fasting insulin and HOMA-IR results. In obese children, plasma leptin levels did not correlate with BMI, fasting insulin or TNF alpha. Conclusion: Plasma leptin concentrations did not show any correlation with TNF alpha levels in obese children. Furthermore, plasma leptin and TNF alpha concentrations were similar in hyperinsulinemic and normoinsulinemic obese children.