The testing of antihypertensive medications in children is timely because physicians caring for hypertensive childrenespecially pediatric nephrologists, cardiologists, endocrinologists, and adolescent medicine physicians, as well as clinical pharmacologistshave as therapeutic options almost no approved drugs for children, and somewhat outdated official recommendations.^1,2 In the balance of this need lie the problems inherent in using pediatric populations for clinical trialsa problem that has been recognized by leaders in the pharmaceutical industry. A representative of the pharmaceutical industry concurred that a particularly difficult pediatric population are hypertensives. The incidence (and prevalence) of hypertension in childhood is low, between 2% and 5% in some series.¹ Even in many of the population groups in which numerous epidemiologic studies have shown that adult hypertension is frequentparticipants with diabetes mellitus, obesity, certain racial groups (black, Native American, Latino), and in families with essential hypertensionthe prevalence of hypertension during childhood is low, but blood pressure values may progress over time to be hypertensive.^2,3 Placebo control and placebo arm of treatment trials are problematic because the only children in whom recommendations for therapy exist are those whose blood pressures are above the 95th percentile.^2,3

The identification of hypertension is further beset by a considerable number of technical issues, including white coat hypertension, appropriate cuff size for arm length or weight, height related norms, current paucity of validation of ambulatory blood pressure measurements, and measurement devices in North American children, which Korotkoff sounds to evaluate (4th or 5th) and at which ages, and whether the 4th or 5th sound is more relevant in children under 13-years of age.⁴ Studies in children who are the offspring of adult hypertensive participants have shown that reproducible stress testing (eg, playing a video game at an accelerating speed) may unmask a tendency for blood pressure elevation for chronological . . . [Full Text of this Article]