Childhood obesity and adult cardiovascular disease risk: a systematic review.

Background: Although the relationship between adult obesity and cardiovascular disease (CVD) has been shown, the relationship with childhood obesity remains unclear. Given the evidence of tracking of body mass index (BMI) from childhood to adulthood, this systematic review investigated the independent relationship between childhood BMI and adult CVD risk. Objective: To investigate the association between childhood BMI and adult CVD risk, and whether the associations observed are independent of adult BMI. Design: Electronic databases were searched from inception until July 2008 for studies investigating the association between childhood BMI and adult CVD risk. Two investigators independently reviewed studies for eligibility according to inclusion/exclusion criteria, extracted the data and assessed study quality using the Newcastle–Ottawa Scale. Results: Positive associations between childhood BMI and adult blood pressure or carotid intima-media thickness were generally attenuated once adjusted for adult BMI. Associations between childhood BMI and CVD morbidity/mortality had not been adjusted and do not provide evidence of an independent relationship. Negative associations between childhood BMI and blood pressure were observed in several adjusted data sets. Conclusions: Little evidence was found to suggest that childhood obesity is an independent risk factor for CVD risk. Instead, the data suggest that relationships observed are dependent on the tracking of BMI from childhood to adulthood. Importantly, evidence suggests that risk of raised blood pressure is highest in those who are at the lower end of the BMI scale in childhood and overweight in adulthood. The findings challenge the widely accepted view that the presence of childhood obesity is an independent risk factor for CVD and that this period should be a priority for public health intervention. Although interventions during childhood may be important in prevention of adult obesity, it is important to avoid the potential for negative consequences when the timing coincides with critical stages of neurological, behavioural and physical development.