Salivary levels of Interleukin-6 and Tumor Necrosis Factor-alpha in girls aged 7–17 years practicing volleyball

Introduction

The purpose of the study was to evaluate the salivary concentrations of Interleukin-6 (IL-6) and Tumor Necrosis Factor-alpha (TNFα) and correlate the findings with the caries index, body mass index (BMI), potency of lower limbs (vertical jump), cardiorespiratory fitness, and risk of developing cardiovascular diseases in girls practicing volleyball.

Material and methods

Two studies were performed: 1) a cross-sectional study (n = 120) on the association of IL-6 and TNFα with the caries index, anthropometric measures, physical tests, and experience in volleyball practice; 2) longitudinal study (n = 63) on the effects of 8 weeks of training on salivary IL-6 and TNFα in girls with intermediate experience in volleyball and competitive girls.

Results

The median levels of IL-6 were 1.98 [1.55–3.11] pg/ml and TNFα, 0.46 [0.28–0.59] pg/ml and these did not correlate with the caries index, BMI, training volume, training practice, or cardiovascular risk. A correlation was observed between IL-6 and TNFα (r = 0.34; p < 0.001), IL-6 and vertical jump height (r = −0.28, p < 0.005), and TNFα and age (r = 0.33; p < 0.001). After 8 weeks of training, TNFα levels increased in the intermediate and competitive groups (p < 0.05), while IL-6 levels decreased only in the intermediate level group (p < 0.05).

Conclusion

the median levels of IL-6 and TNFα did not correlate with the caries index, BMI, training volume, experience practice, or cardiovascular risk. Salivary levels of IL-6 were downmodulated in the group with intermediate experience and TNFα was upmodulated by training.