Abstract
BACKGROUND: Endothelial dysfunction appears early in the development of cardiovascular disease and is associated with type 2 diabetes. We, therefore, tested the hypothesis that endothelial dysfunction is already present in healthy Chinese adolescent participants at risk of type 2 diabetes and associates with physical activity. METHODS: We investigated the flow-mediated dilation in 65 first-degree relatives (normal tension, normal glucose tolerance) and 62 age-, sex- and BMI-matched controls without a family history of type 2 diabetes by ultrasound. Physical activity level was assessed using the Global Physical Activity Questionaire and type 2 diabetes family history through self-reporting. The association between physical activity and flow-mediated dilation was evaluated by Pearson correlations and multiple regressions in adolescents with or without a family history of type 2 diabetes. RESULTS: Female adolescents display better flow-mediated dilation than males. Adolescents with a family history of type 2 diabetes had significantly impaired flow-mediated dilation than healthy controls. Among the parameter detection in the blood, the flow-mediated dilation is only positively associated with high-density lipoprotein cholesterol level, but not others. Interestingly, flow-mediated dilation is positively corrected with physical activity scores in both the male and female adolescents, while slightly impaired but not significant in adolescents with a family history of type 2 diabetes. CONCLUSION: Studies in adolescents are important to understand the early pathogenesis of type 2 diabetes. Findings of this investigation suggest that family history of type 2 diabetes may play a role in regulating the vascular function in Chinese adolescents. Given the impaired flow-mediated dilation in individuals with family history and the effects of physical activity in improved flow-mediated dilation, people with a family history of type 2 diabetes may need higher physical activity levels to attenuate their susceptibility to impaired flow-mediated dilation.