International Differences in Secular Trends in Childhood Blood Pressure

Hypertension is a potent independent risk factor for stroke, myocardial infarction, heart failure, renal failure, and mortality in adults.1 Although most of these adverse outcomes occur in adulthood, it has become clear that hypertension is a life course problem that can become evident in childhood and can be progressive throughout childhood into adolescence and adulthood.2 It has also become clear that elevated blood pressure in childhood is associated with early markers of cardiovascular abnormalities, including left ventricular hypertrophy3 and atherosclerosis.4 For these reasons, there has been an increasing focus on the identification and treatment of children and adolescents with hypertension and the prevention of the occurrence of hypertension in the first place.5Article see p 397There is still much to be learned about the mechanisms involved in the development of hypertension. In general, it is thought that both genetic and environmental forces are important. It is clear that there is a familial clustering of high blood pressure, which probably reflects both shared genes and a shared environment. Some specific genetic abnormalities have been discovered that result in blood pressure elevation.6 However, these genetic abnormalities do not explain a very large proportion of the primary hypertension observed in the population. Studies are underway to determine the multiple other genetic influences that probably interact with environmental factors and underpin the development of primary hypertension.7Environmental factors involved in the pathogenesis of primary hypertension include lifestyle factors, such as diet and physical activity, and other factors, such as intrauterine growth retardation, as well. The most common lifestyle factor associated with hypertension is the development of obesity. Obesity has a number of adverse health effects, but it is clearly associated with blood pressure elevation in both adults and children.8 So, although some clinically useful approaches …