Cardiovascular risk factors in childhood.

It is regrettable that although the incidence of fatal coronary heart disease on the other side of the Atlantic and in Australia is falling, the toll here, even if not increasing at the great pace of the 'fifties and 'sixties, is only just beginning to level off. Few of us can afford to be complacent, and we as paediatricians have a duty to sow the seeds of longevity in our patients. For these reasons it seems timely to review cardiovascular risk factors in children, not least with the admonitions of the Reith lecturer ringing in our ears about our lack of concern for preventive medicine. Atherosclerotic disease begins early in life. Indeed already at birth there is a difference between the aorta of boys and that of girls which might suggest that testosterone is actually atherogenic.1 Perhaps we have to settle for these sex ratios of susceptibility but numerous studies have shown the importance of risk factors in adult populations and now is the time to look to an age group in which the disease is not already far advanced. The way that cholesterol forces itself into the arterial wall is ultimately the crucial point to consider. Here the interactions of endothelial injury, platelet stickiness, and a leaky endothelium lead to invasion of the vessel wall by lipoproteins and other foreign substances. Repair then takes place and it seems that these repeated brief insults become cumulative over the years and bad luck or bad management leads to the final event of an infarct, by which time the individual needs not just a routine service to repair major damage but a whole new set of plumbing. The liability of an individual's arteries to undergo atherosclerotic change varies with age, sex, geographical location, and race. Lesions seem to be related to serum cholesterol and to dietary fat and salt intakes when comparing populations but the data are insufficient (and hence the advocacy of extreme stances) to confirm these associations on an individual basis within a population. Hypertensive subjects, diabetics, and smokers fare badly, but obesity and exercise on their own seem to be 412 receding in importance; they may exacerbate other factors but it is the interaction of the risk factors that counts. The definition of what constitutes significant hypertension, hyperlipidaemia, or obesity is vital. Are minor degrees important? Simple measurement in the population is not adequate: this gives the situation as it is and not necessarily as it should be. What is the contribution of time to this; does it interact with a small degree of risk to increase its force? Most important of all, what is the genetic liability to suffering the consequences of the various risk factors? The same quantity of factor manifestly does not carry the same risk in different families so it is best to choose healthy parents. Whether this is to get good genes or a good family environment is hard to say but to have maximum impact a paediatrician could be justified in first pursuing the yet-healthy children of risk-loaded parents with a poor family history. The increasing fashion in the private sector for medical checks on husbands and wives could be the beginning of an important contribution: contact tracing has, after all, a pretty good record in the case of the infectious diseases.