S-43-1: THE CHANGING EPIDEMIOLOGY OF HYPERTENSION IN CHILDREN AND ADOLESCENTS

Abstract

Some scientific concepts take time to overcome initial disbelief before they are finally embraced by the research community. One of these concepts is hypertension in children and adolescents. Little was known about childhood hypertension until the early 1980 s, mainly because blood pressure was not commonly measured in pediatric clinical practice. In the few cases blood pressure levels were determined to be abnormal in children, they were considered to be secondary hypertension resulting from an underlying condition. Even though secondary causes of hypertension tend to occur more often in hypertensive children than in adults, its prevalence is only about 1 percent overall, leaving primary hypertension especially in adolescents as the most frequent type. Even when there are many studies that have assessed the prevalence of hypertension in children and adolescents, scientists have faced difficulties to state this prevalence for three main reasons. To begin with, blood pressure normally changes with increasing age and body size. This makes establishing a fixed cutoff for values of systolic and diastolic blood pressure elevation rather challenging. This difficulty has led to the use of percentiles based on age, sex, and height to define the normal distribution, with a hypertensive level of blood pressure in the 95th percentile or higher. Another obstacle is that there is a variety of different definitions of hypertension used by the three most recent clinical practice guidelines coming from Europe, the United States and Canada. The last challenge is focused on the beat-to-beat blood pressure variability, the definition of hypertension requires that systolic and/or diastolic blood pressure to be persistently higher than the established thresholds on three separate occasions. Many cross-sectional studies with only one single measurement of blood pressure have not been able to define the prevalence of hypertension. The epidemiology of hypertension in childhood and adolescence can be linked to the worldwide obesity epidemic. Hypertension is more prevalent than before, with primary hypertension being the main type. It is well known that the factors related to primary hypertension can be modified, therefore childhood is a period in which prevention could be effective. If prevention is followed throughout childhood, it could contribute to a healthier young adulthood in the long run. Therefore, primordial prevention is an opportunity not to be missed.