Author(s): HOMS AVILA, J., VASILEVA, F., CAZORLA-GONZÁLEZ, J., PLANS-SALAS, E., FONT-LLADÓ, R., PRATS-PUIG, A., Institution: ESCOLA UNIVERSITARIA DE LA SALUTA I L'ESPORT EUSES-UNIVERSITAT DE GIRONA, Country: SPAIN, Abstract-ID: 2267

INTRODUCTION:
Obesity is a complex and multifactorial chronic disease caused by the interaction between the genotype and the environment. A sedentary lifestyle in children can lead to a decrease in physical activity, which can contribute to the development of obesity and other health related problems such as cardiovascular diseases, metabolic syndrome, and type 2 diabetes. The World Health Organization (WHO) recommends that children and adolescents accumulate 60 minutes of moderate or vigorous physical activity (PA) per day (1), therefore regular PA during childhood is one of the most effective means of improving and preserve health.
Saliva offers a promising diagnostic alternative to detect inflammatory, metabolic and cardiovascular risk factors in pediatric populations. Saliva sample collection offers advantages such as being an easy and non-invasive technique. Therefore, the use of saliva as a diagnostic and prognostic fluid is of interest for childhood obesity research.
Our aim was to study whether obesity and physical activity can influence the salivary proteome.

METHODS:
BMI was calculated as follows: (Weight (kg))/〖Height (m)〗^2. Age- and sex-adjusted standard deviation scores (SDS) for body mass, height and BMI were calculated using regional normative data. Participants were classified as underweight, normal weight, overweight or obese (2). Physical activity level (sedentary, light, moderate, moderate to vigorous, and vigorous) was assessed using the triaxial accelerometer that allows determining the quantity and quality of physical activity (Actigraph GT3X). Salivary proteome analysis was performed on 20 saliva samples [7.53±0.33 years; 56% girls] by MALDI-TOF mass spectrometry using the positive linear mode and a mass range of 5 to 20 KDa. Differences in mass spectra (MS) and peaks (m/z) were analyzed using the Mann-Whitney U test.
RESULTS:
By comparing the proteome profiles in saliva of normal-weight and obese children, a total of 20 MS peaks with significant intensity differences (p < 0.01) were identified. When children meeting and not meeting physical activity recommendations were compared, 2 peaks were identified (p < 0.05).
CONCLUSION:
These results suggest that both, obesity and physical activity can change the salivary proteome profile in children, which would allow the identification of core salivary proteins and the correlation of salivary levels of these core proteins with obesity, cardiovascular parameters and a healthy lifestyle in children.

(1) WHO guidelines on physical activity and sedentary behaviour ISBN 978-92-4-001512-8
(2) Cole TJ, Flegal KM, Nicholls D, Jackson AA. Body mass index cut offs to define thinness in children and adolescents: international survey. BMJ (Clinical research ed.) 2007-07-28. DOI: 10.1136/bmj.39238.399444.55