EVIDENCE is constructing that cardiovascular disease risk factors (CVDs) observed in children are a predictor of cardiovascular events in middle age. The question for GPs and other doctors is what should be the next step?
A global team of researchers from the International Childhood Cardiovascular Cohort (i3C) Consortium reported this month in the New England Journal of Medicine that CVD risk factors, when measured in childhood, strongly predict the occurrence of events. CVD in the Middle Ages. The results were obtained from a 40-year follow-up study of 38,589 children in the United States, Finland, and Australia.
Risk factors included those conventionally used in adult MCV risk screening: blood pressure, serum lipids, body mass index, and smoking, factors that have been repeatedly demonstrated in prospective cohort studies in the elderly. adulthood as important predictors of posterior ECV.
However, no similar tests are available for these same risk factors when seen in children. The reason for this is that in order to obtain this evidence, a study of a sufficiently large and very long-lasting sample size is required, covering the period from childhood to the age at which cardiovascular events begin to occur. usual: middle age. The practical difficulties of conducting such a study seemed insurmountable until 2002, when Australian researchers, who had embarked on a follow-up of Australian schoolchildren surveyed in 1985, suggested to their counterparts in the United States and Finland that could group their cohort data and track them for the occurrence of mid-life CVD events. All cohorts had begun enrolling participants in the 1970s and 1980s and had measured ECV risk factors at least once during childhood between the ages of 3 and 19 years.
The five risk factors in children that were associated with the risk of an adult CVD event, most of which were myocardial infarction or fatal or non-fatal stroke, were systolic blood pressure, serum cholesterol. and triglycerides, body mass index, and smoking.
All risk factors in children were significantly associated with an increased risk of cardiovascular events in adults, both fatal and non-fatal, with risk ratios for those whose values were above a cut-off point. clinically defined, e.g. High BMI or high cholesterol: between 3.39 and 2.13. The risk among those with more than one risk factor, identified by a risk “score,” was considerably higher than for a single risk factor. It was estimated that children whose combined risk scores were in the upper 5% of the distribution had a risk of suffering a cardiovascular event more than six times more than children in the lower end of the distribution of the risk factors. risk
These estimated risks are reasonably similar to those observed in adults and are clinically significant.
The question to be asked in such an observational study is whether we should assume that the observed associations are causal. The fact that early atherosclerosis has been found to be frequently present in children under the age of 10 makes the findings very plausible. The design of the study also makes it unlikely that the biases commonly found can explain the findings. Although individual risk factors were not adjusted to each other, the set of risk factors was adjusted for cohort location, socioeconomic status, and race. Loss of follow-up, which is a potentially important source of bias in prospective cohort studies, is not a concern here because high risks were found in the analysis involving well-defined fatal events identified by death records.
Finally, in all observational studies we are concerned that the inverse causality, by which the disease causes changes in risk factors, may explain the results. In this study, risk factors were measured long before any disease-related symptoms could be experienced.
We believe that these findings need to be taken very seriously, especially in the context of the childhood obesity epidemic, which has occurred to a large extent since these cohorts began. The editor of the New England Journal of Medicine wrote in an editorial attached to the main article:
“Yes [cardiovascular] Risk factors can be identified at the beginning of life, we, as doctors, have opportunities to address health issues soon and we could untie the risk of an inexorable march towards CVD and death. We have been waiting for hard data to show that the risk factors observed in childhood predict future illnesses, and now we have a good start with CVD. “
The question, though, is what should be the next step?
Recommendations have been developed in recent years on policies and implementation strategies for the prevention of CVD from childhood, but in an environment where there was no certainty about the importance of reducing these risk factors. A concerted effort to review the effectiveness of various strategies to address the problem of CVD risk factors in children is now essential. This effort must involve government and health care policy makers to ensure that optimal approaches are identified and implemented.
Professor Terence Dwyer is Professor Emeritus of Epidemiology at Oxford University. He is a Professor at the Murdoch Children’s Research Institute in Melbourne and an Honorary Professor in the Department of Pediatrics at the University of Melbourne. He was the lead author of the New England Journal of Medicine article cited in this article.
Professor Alison Venn is the director of the Menzies Institute for Medical Research at the University of Tasmania.
The statements or opinions expressed in this article reflect the views of the authors and do not necessarily represent the official policy of the WADA, MJA or InSight + unless otherwise stated.
Subscribe to the free weekly InSight + newsletter here. It is available to all readers, not just registered physicians.
If you would like to submit an article for consideration, please send a version of Word to mjainsight-editor@ampco.com.au.