The effects of exercise on coronary heart disease risk factors in children.

Coronary heart disease (CHD) is now recognised as a paediatric problem despite the fact that clinical symptoms of this disease do not become apparent until much later in life. Epidemiological studies of risk factors in children have now been conducted. These studies suggest that the risk factors for cardiovascular disease in adults, which include a family history of heart disease, elevated blood lipids (serum cholesterol and triglycerides), obesity, hypertension, smoking, diabetes mellitus and inadequate physical activity, can be identified in children. Several investigators have reported the existence of one or more risk factors in more than 50% of the children they have examined. It is now clear that we can detect most children who are potentially at risk for CHD. The notion of 'tracking' some of the most common CHD risk factors in children has been used in several studies. Results from this type of research indicate that children who are at the extreme end of the distribution and have high levels of blood pressure, adverse lipid levels and are obese will continue to exhibit these coronary risk factors as they grow. The research completed at present does not answer the question of whether children who exhibit a coronary-prone risk factor profile will exhibit this same profile at an age when one is most likely to develop the clinical manifestations of CHD. It does make sense, however, to identify those children who may be at risk for developing premature CHD and to initiate safe interventions such as behaviour modification, changes in diet and increases in physical activity. These have all been shown to alter risk factors which are associated with increased relative risk of CHD in adults. It should be noted that in adults regular aerobic exercise often may alter all risk factors for CHD, including hypertension and diabetes. Whether regular aerobic exercise will induce similar changes in children is not fully understood.