RELATIONSHIP BETWEEN PHYSICAL ACTIVITY, DIETARY INTAKE AND BONE PARAMETERS IN 10-12 YEARS OLD HUNGARIAN BOYS AND GIRLS

Objectives: Physical activity (PA) and adequate macro- and micronutrient intake have favourable influence on the bone status. The aim of this study was to analyse the relationships among PA, anthropometric data, dietary intake and ultrasound bone characteristics in children. Methods: 10-12 years old Hungarian children (N = 123, 59 girls, 64 boys) provided physical activity, diet, anthropometric and bone data. PA was measured with accelerometer (Actigraph GT3X+). Diet was evaluated with three-day, 24-hour food recall. Calcaneal quantitative ultrasound (QUS) bone parameters were registered with Sonost3000 bone densitometer. Results: Nutrition and anthropometry did not differ by gender. The values of broadband ultrasound attenuation (BUA) were significantly higher in boys. Girls spent significantly more time being sedentary, boys had greater light, moderate, vigorous, and moderate to vigorous physical activity (MVPA) levels. The children accumulated more than twice the suggested amount of public health guidelines for MVPA. QUS parameters correlated significantly with vigorous physical activity in boys, and with age, height, weight, fat percentage, and body mass index (BMI) for both genders. There was no significant relationship between nutrition and QUS; however, inadequate vitamin K intake correlated with less favourable bone parameters. Multiple linear regression analysis confirmed the importance of vigorous PA-speed of sound (SOS): beta = 0.358, p = 0.006; BUA: beta = 0.340, p = 0.007; bone quality index (BQI): beta = 0.377, p = 0.002; vitamin K intake - SOS: beta = 0.256, p = 0.025; BUA: beta = 0.235, p = 0.033; BQI: beta = 0.295, p = 0.007; BMI -SOS: beta = 0.207, p = 0.064; BUA: beta = 0.455, p < 0.001; BQI: beta = 0.284, p = 0.008; and age -SOS: beta = 0.450, p < 0.001; BUA: beta = 0.318, p = 0.004; BQI: beta = 0.444, p < 0.001). Conclusions: Changes in the characteristics of ultrasound bone parameters among 10-12 years old children mainly depended on the amount of intense PA, adequate vitamin K intake and anthropometric variables related to age.