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Childhood obesity not only increases the risk of cardiovascular disease in later life but also is linked to cardiovascular damage before adulthood, researchers argued.
"Clinical evidence is accumulating to suggest that the cardiovascular damage, once only observed in adults, is also occurring in obese children," noted Angela Devlin, PhD, and colleagues at the University of British Columbia in Vancouver.
In a review of that evidence, published in the Journal of the American College of Cardiology, Devlin and colleagues called for a research program that would tease out the mechanisms involved, identify effective prevention schemes, and establish norms that would take into account the changes associated with growth and development.
Despite some important knowledge gaps, Devlin and colleagues argued, "research to date illustrates that obesity during childhood and adolescence is associated with various measurable alterations in cardiovascular structure and function."
An important implication, they concluded, is that "early identification of cardiac dysfunction in children with obesity is warranted to mitigate long-term complications."
But they cautioned there is "limited" understanding of the combined effects of multiple risk factors, how much weight should be given to individual risk factors, and the effect of length of exposure.
Moreover, many of the tools used in research -- with the exception of measuring left ventricular mass -- are not routinely employed in the clinic, they noted.
"Thus," they argued, "the extent of obesity-related cardiovascular changes (is) likely under-recognized and therefore under-managed."
Devlin and colleagues noted that childhood obesity has been rising, reaching nearly 17% in 2007-2008 in the U.S., although a recent CDC report suggested the trend may be waning, at least in some groups.
And there is increasing evidence that childhood obesity affects both cardiac and vascular structure and function, although many of the mechanisms remain unclear in the absence of longitudinal studies, they reported.
Among the alarming clinical studies, obese children:
- With risk factors for atherosclerosis had a "vascular age" similar to that of a 45-year-old healthy adult.
- Had significantly greater left atrial and left ventricular dimensions than those with a healthy body mass index.
- Had higher levels of epicardial fat, which has been proposed as a cardiovascular risk factor.
- Had altered cardiac mechanics, including diastolic dysfunction and systolic dysfunction at rest and during exercise.
Missing from the evidence is a clear understanding of what is normal in children and what can be expected as they grow and develop, Devlin and colleagues reported.
Indeed, a recent study suggested that -- especially for boys -- childhood obesity can resolve itself when growth spurts occur.
"The cascade of events leading to cardiovascular disease may vary in response to genetic and environmental factors as well as the presence or absence of other comorbidities such as hypertension or dyslipidemia," they wrote.
While some of the important factors are known, they commented, "many of the specific mechanisms and interactions are incompletely understood in children."
Importantly, Devlin and colleagues argued, prevention of obesity in children is needed but "the indications for intervention and the most effective therapy for obese children with cardiovascular abnormalities (have) not been adequately elucidated."
The researchers had support from the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council, British Columbia Mental Health and Addiction Services, MITACS, the Canadian Diabetes Association, and the Child and Family Research Institute.
The authors said they had no conflicts of interest to disclose.
- Reviewed by F. Perry Wilson, MD, MSCE Instructor of Medicine, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner
Journal of the American College of CardiologySource Reference: Cote AT, et al "Childhood obesity and cardiovascular dysfunction" J Am Coll Cardiol 2013; DOI: 10.1016/j.jacc.2013.07.042.