Combined Association of Diet and Cardiorespiratory Fitness with Metabolic Syndrome in Chinese Schoolchildren

Objective To investigate the combined impact of diet and cardiorespiratory fitness (CRF) on metabolic syndrome (MetS) among Chinese schoolchildren. Methods A cross-sectional study among 615 children (354 boys and 261 girls) aged 9.6 +/- A 0.6 years was conducted in Wuhan, China, from May to June 2010. Body mass index, waist circumference, CRF, blood pressure, lipids, glucose, and pubertal status were assessed. MetS was defined by the criteria proposed by De Ferranti. Based on data from a food frequency questionnaire, a diet score was created for each food item and then summed. Gender-specific median values were set as the cut-off points for the classification of high and low CRF. Results The highest prevalence of MetS (15.7 %) was observed among participants in the low tertile of diet scores and having a low level of CRF. Multivariate logistic regression showed that the odds ratio for MetS was 0.30 (95 % confidence interval 0.09-1.00) among children in the medium tertile of diet scores with low CRF, 0.24 (0.07-0.89) among those in the high tertile of diet scores with low CRF, 0.07 (0.02-0.33) among those in the low tertile of diet scores with high CRF, and 0.08 (0.01-0.58) among those in the high tertile of diet scores with medium CRF compared with those in the low tertile of diet score with low CRF. Conclusions Findings of the present study suggest that diet and CRF are synergistically associated with the risk of MetS in Chinese schoolchildren.