Tumor necrosis factor alpha (TNF-alpha) is suspected to play a role in obesity and concomitant metabolic disturbances. The aim of the study was to determine fasting serum concentrations of TNF-alpha in overweight and obese children and to analyse the relationships between TNF-alpha and insulin resistance and lipid disturbances. The additional aim was to assess correlations between TNF-alpha and total fat mass, body mass index (BMI), WHR, leptin and plasminogen activator inhibitor type 1 (PAI-1), as the factor of increased risk of atheromatosis.
The study was performed in a group of 160 children aged 6-18.5 years: 127 overweight or obese and 33 healthy lean children (control group). The anthropometric measurements, BMI, WHR, fat-free mass, Tanner pubertal stage and blood pressure were determined. The fasting serum concentrations of TNF-alpha, glucose, insulin, lipids and fibrinogen were analysed in studied children. In overweight and obese subjects oral glucose tolerance test (OGTT) was done, serum leptin and plasma PAI-1 concentrations were determined. Atherogenic and insulin resistance indexes were counted. Statistic analysis was done.
The serum TNF-alpha concentration in overweight and obese children and lean controls were comparable. This fact doesn't deny the role of TNF-alpha in pathogenesis of obesity. TNF-alpha concentration grows in serum of girls according to degree of abdominal obesity, determined with increase of WHR. Fat-free mass and BMI don't influence TNF-alpha level. Carbohydrate disturbances in obese children may not depend only on TNF-alpha. There are relationships between TNF-alpha and decreased HDL cholesterol and increased triglycerides (TG) levels in serum of overweight and obese children, mainly in II-III pubertal stage. Special care should be provided for children with excessive body weight at the beginning of puberty because of increased intensity of metabolic syndrome in this period and greater risk of early atheromatosis. Special care should be also provided for boys with increased TG serum levels, because of growing atherogenesis risk, determined with higher plasma concentration of PAI-1 in them and positive correlation between TNF-alpha and PAI-1. Regulation ofleptin production and secretion may also be under the control of other factors than TNF-alpha.