Childhood obesity: The increasing vascular drama

Obesity is one of the most important health problems in industrialized countries irrespective of socio-economic status, age, sex or ethnicity. The prevalence of childhood obesity in children has reached alarming levels, even in developing countries. It is estimated that about 1 billion people worldwide are overweight, with 22 millions being under the age of 5 years and 300 million people are obese. By 2010 it is estimated that 26 million children in E.U. countries will be overweight, including 6.4 million who will be obese.

The reasons for childhood obesity include environmental factors, lifestyle preferences, and also cultural background. However, in our affluent society an increase in caloric and fat intake is one of the major causes for developing overweight and obesity. On the other hand, there is rising evidence that a marked decline in physical activity also plays a major role in the dramatically increasing rates of obesity all around the world. Consequently, both over-consumption of calories and reduced physical activity are involved in childhood obesity.

Already in early childhood, overweight and obesity are associated with the classical risk factors for the development of cardiovascular diseases like diabetes or pre-diabetes, high blood pressure or high cholesterol levels. These diseases all together contribute to the so called "metabolic syndrome". Furthermore, the dramatic increase in weight also results in orthopaedic disorders, like erosions and arthrosis of waist or knee joint, making any physical activity impossible, even if the children were willing to do it.

Given the fact that up to 50% of obese children are suffering from metabolic syndrome, it is conceivable that these children are already characterized by vascular damages resulting in developing plaque formation, referred to as atherosclerosis. It is well known that a normal function of vessels depends on a balance between relaxing and contracting factors produced within the internal lining of arterial vessels, the endothelium. The major endothelium-derived relaxing factor is nitric oxide. The availability of nitric oxide is critically influenced by the above mentioned risk factors and diseases leading to a mismatch between relaxation and contraction of the vessels. The occurrence of endothelial dysfunction is considered to be the earliest stage of atherosclerosis and can be present years before an atherosclerotic lesion will be detectable. Moreover, recent studies suggest a prognostic impact of endothelial dysfunction. That means, if endothelial dysfunction is present, the likelihood of developing a cardiovascular disease or to die from it is considerably increased. With our present, still ongoing study, we aim to investigate whether obesity in early childhood is associated with endothelial dysfunction or other damages of the vessels as an early stage of atherosclerosis. Furthermore we are interested in the relationship between markers of metabolic syndrome (high blood glucose, elevated blood pressure or cholesterol) and the degree of vessel injury.