Analysis of ghrelin, leptin, and interleukin-6 salivary concentration among children aged 7–10 years and its relationship with nutritional status and some anthropometric data

Introduction
Obesity is a complex condition with multifactorial aetiopathogenesis. Adipose tissue is reservoir of many adipokines which play a great role in proinflammatory response in obesity. Aim of the study: Comparative assessment of ghrelin, leptin, and interleukin-6 (IL-6) salivary concentration among children having proper and excess of body mass. Analysis of the interrelationship between the obtained concentrations of substances and selected anthropometric parameters and blood pressure values in the studied children.

Material and methods
The study group comprised 102 children aged 7–10 years. The nutritional status of children was assessed by the use of the BMI index. The control group (n  = 74) comprised children with proper body mass, and the study group (n = 28) contained children having overweight/obesity. Saliva samples were taken from all children at school. Subsequently, some anthropometric parameters and blood pressure values of the children were measured. The laboratory assessment of substances was made by ELISA method. Next, statistical analysis of all obtained results was performed using professional software.

Results
Salivary ghrelin, leptin, and IL-6 concentrations were statistically significantly higher in the study group than in the control group (p = 0.001). The study revealed a positive correlation between salivary ghrelin concentration and BMI in the whole study population (p = 0.001), and between ghrelin concentration and body weight, waist circumference, hip circumference, and waist-to-hip ratio in all subjects. In the study group, the BMI value was positively correlated only with IL-6 saliva concentration (p = 0.005).

Conclusions
The study revealed significant differences between saliva ghrelin, leptin, and IL-6 concentration between the control group and the study group. The above findings can be a good predictor with which to detect co-existing metabolic alternations in obese patients.