C-reactive protein in schoolchildren and its relation to adiposity, physical activity, aerobic fitness and habitual diet

Objective: To investigate the relation between C-reactive protein (CRP), adiposity, physical activity, aerobic fitness and habitual diet in a cohort of schoolchildren. Methods: A cross-sectional study of 164 schoolchildren aged 12–13 years was conducted in two schools. Adiposity was estimated using body mass index and waist circumference. Blood samples were taken after an overnight fast and measured for CRP. Aerobic fitness and habitual physical activity were assessed using the 20 metres multistage fitness test, and a seven-day recall, respectively. A seven-day food diary provided measures of dietary intake. Results: To improve the distribution of this variable, CRP levels were logarithmically transformed in all analyses. There was no significant difference in mean CRP concentration between boys (1.07 (1.33) mg/l) and girls (1.24 (1.87) mg/l) (p⩾0.05). Compared to girls, boys reported significantly higher (i) aerobic fitness 59.2 (20.3) shuttles vs 42.9 (15.3) shuttles, (ii) vigorous activity levels per week 92 (123) minutes vs 11.2 (34.6) minutes and (iii) waist circumference 69.8 (1.1) cm vs 65.2 (0.9) cm (p⩽0.05). Among boys and girls, adiposity was significantly associated with log transformed CRP (p⩽0.05). CRP was not significantly related to any other variable. Conclusion: Elevated CRP was evident in this cohort; however, whether high CRP levels during childhood and adolescence leads to an increased risk of CVD in later life has not been determined. Adiposity was related to CRP concentration, suggesting that reducing adiposity may be effective in lowering CRP and preventing future cardiovascular events.