Title : The associations of diet quality and cardiometabolic health in children and the mediation role of cardiorespiratory fitness
Abstract:
Background:
The mechanisms linking diet quality to cardiometabolic health in children and adolescents remain inadequately understood. This study aimed to investigate the associations between diet quality and cardiometabolic health in Chinese youth, with a specific focus on the mediating role of cardiorespiratory fitness (CRF) in these associations.
Methods:
A total of 1,389 children aged 8 to 10 years were recruited for this cross-sectional study in September 2022 in Ningbo, China. Anthropometric measurements, including waist circumference, were collected, and overnight fasting blood samples were obtained to assess metabolic indices such as fasting insulin, triglycerides, and the ratio of total cholesterol to high-density lipoprotein cholesterol (HDL-C). The cardiometabolic risk (CMR) score was calculated as the sum of age- and sex-specific Z-scores of waist circumference, systolic blood pressure, triglycerides, the total cholesterol to HDL-C ratio, and homeostatic model assessment for insulin resistance (HOMA-IR). CRF was evaluated using the 20-meter shuttle run test, a well-established measure of aerobic endurance. Diet quality was assessed via the Diet Quality Questionnaire (DDQ), and a Global Dietary Recommendations (GDR) score was derived from the DDQ responses. Generalized linear mixed models were employed to explore associations between the GDR score and various cardiometabolic indicators. Mediation analyses were conducted to assess the extent to which CRF mediated the relationships between diet quality and cardiometabolic risk.
Results:
Our analysis revealed that, after adjusting for age, sex, and physical activity, a higher GDR score, indicative of better diet quality, was significantly associated with improved cardiometabolic outcomes, including lower fasting insulin (β = -0.013; 95% CI: -0.024, -0.002; P = 0.023), lower HOMA-IR (β = -0.014; 95% CI: -0.026, -0.002; P = 0.019), and a reduced CMR score (β = -0.074; 95% CI: -0.139, -0.006; P = 0.030). Mediation analyses demonstrated that CRF partially mediated the associations between diet quality and cardiometabolic risk. Specifically, CRF explained 26.1% of the relationship between GDR score and fasting insulin, 25.3% of the relationship with HOMA-IR, and 32.9% of the relationship with CMR score (all P < 0.05).
Conclusion:
Our findings suggest that in Chinese children, poor diet quality is associated with increased cardiometabolic risk. Moreover, cardiorespiratory fitness plays a crucial mediating role in these associations, emphasizing the importance of both dietary improvements and physical fitness in promoting cardiometabolic health in youth.
