7th Brazilian Guideline of Arterial Hypertension: Chapter 10 - Hypertension in Children and Adolescents

Arterial hypertension was identified as the major source of combined mortality and morbidity, representing 7% of global disability-adjusted life years.1 The adoption of the BP definitions and normalization of the “National High Blood Pressure Education Program” (NHBPEP) 20042 has standardized the BP classification in the pediatric population. The percentage of children and adolescents diagnosed with AH is estimated to have doubled in the past two decades. The current prevalence of AH in the pediatric population is around 3% to 5%,3-5 while that of PH reaches 10% to 15%,3,4,6,7 and such values are mainly attributed to the large increase in childhood obesity.8 The etiology of pediatric AH can be either secondary, most often associated with nephropathies, or primary, attributed to genetic causes with environmental influence, predominating in adolescents.

Pediatric AH is usually asymptomatic, but as many as 40% of hypertensive children have LVH at the initial diagnosis of AH. Although oligosymptomatic in childhood, LVH is a precursor of arrhythmias and HF in adults. 9 In addition, pediatric AH is associated with the development of other changes in target organs, such as increased carotid IMT, arterial compliance reduction, and retinal arteriolar narrowing. Early diagnosis and treatment of childhood AH are associated with a lower risk for AH and for increased carotid atheromatosis in adult life. 10 Therefore, periodical BP measurements in children and adolescents are recommended, even contradicting the U.S. Preventive Services Task Force's suggestion, which considers the evidence of benefits of primary AH screening in asymptomatic children and adolescents insufficient to prevent CVD in childhood or adulthood. 11

Definition and etiology
Children and adolescents are considered hypertensive when SBP and/or DBP are greater than or equal to the 95 th percentile for age, sex and height percentile, on at least three different occasions. 2 Prehypertension in children is defined as SBP/DBP ≥ the 90 th percentile < the 95 th percentile, and in adolescents as BP levels ≥ 120/80 mm Hg and < the 95 th percentile. Stage 1 AH is considered for readings between the 95 th percentile and the 99 th percentile plus 5 mm Hg, while stage 2 AH, for readings > stage 1. The height percentiles can be obtained by using Centers for Disease Control and Prevention's (CDC) growth charts. 12 In addition, normal and high BP levels for children and adolescents are available in mobile apps, such as PA Kids and Ped(z).
In the pediatric population, WCH and MH can be diagnosed based on established normality criteria for ABPM. 13 After a detailed clinical history and physical examination, children and adolescents considered hypertensive should undergo investigation. The younger the child, the greater the chance of secondary AH. Parenchymal, renovascular and obstructive nephropathies account for approximately 60-90% of the cases, and can affect all age groups (infants, children and adolescents), being more prevalent in younger children with higher BP elevations. Endocrine disorders, such as excessive mineralocorticoid, corticoid or catecholamine secretion, thyroid diseases and hypercalcemia associated with hyperparathyroidism, account for approximately 5% of secondary AH cases. Coarctation of the aorta is diagnosed in 2% of the cases, and 5% of secondary AH cases are attributed to other etiologies, such as adverse effects of vasoactive and immunosuppressive drugs, steroid abuse, central nervous system changes, and increased intracranial pressure.
Primary AH is more prevalent in overweight or obese children and adolescents with family history of AH. Currently, primary AH seems to be the most common form of AH in adolescence, being, however, a diagnosis of exclusion, and, in that population, secondary causes should be investigated whenever possible.

Method for BP measurement
Measuring BP in children is recommended at every clinical assessment after the age of 3 years, abiding by the standards for BP measurement. 2 Children under the age of 3 years should have their BP assessed on specific situations. 2,14 For BP measurement, children should be calm and sitting for at least 5 minutes, with back supported and feet on the floor, having refrained from consuming stimulant foods and beverages. The BP should be taken at heart level on the right arm, because of the possibility of coarctation of the aorta. Table 1 shows the specific recommendations for auscultatory BP measurement in children and adolescents. Whenever BP is high on the upper limbs, SBP should be assessed on the lower limbs. Such assessment can be performed with the patient lying down, with the cuff placed on the calf, covering at least two-thirds of the knee-ankle distance. The SBP reading on the leg can be higher than that on the arm because of the distal pulse amplification phenomenon. A lower SBP reading on the leg as compared to that on the arm suggests coarctation of the aorta. Tables 2 and 3 show the BP percentiles by sex, age and height percentile. Figures 1 and 2 show BP values for boys and girls, respectively, from birth to the age of 1 year based on data from the Report of the Second Task Force on Blood Pressure Control in Children -1987. 15 Note: Adolescents with BP ≥ 120/80 mm Hg should be considered prehypertensive, even if the 90 th percentile value is greater than that. This can occur for SBP in patients older than 12 years, and for DBP in patients older than 16 years.
For children/adolescents, ABPM is indicated to investigate WCH and MH, and to follow prehypertensive or hypertensive patients up. 13 The prevalence of WCH has been reported as between 22% and 32%. The use of ABPM should be restricted to patients with borderline or mild AH, because patients with high office BP readings are more likely to be hypertensive. 16

Anamnesis
A careful recollection of data on birth, growth and development, personal antecedents, and renal, urological, endocrine, cardiac and neurological diseases should be performed. The following patterns should be characterized: physical activity; dietary intake; smoking habit and alcohol consumption; use of steroids, amphetamines, sympathomimetic drugs, tricyclic antidepressants, contraceptives and illicit substances; and sleep history, because sleep disorders are associated with AH, overweight and obesity. In addition, family antecedents for AH, kidney diseases and other CVRF should be carefully assessed.

Physical examination
On physical examination, BMI should be calculated. 17 Growth delay might suggest chronic disease, and persistent tachycardia might suggest hyperthyroidism or pheochromocytoma. Pulse decrease on the lower limbs leads to the suspicion of coarctation of the aorta. Adenoid hypertrophy is associated with sleep disorders. Acantosis nigricans suggests insulin resistance and DM. Abdominal fremitus and murmurs can indicate renovascular disease. 18

Complementary tests
Laboratory and imaging tests are aimed at defining the etiology of AH (primary or secondary) and detecting TOD and CVRF associated with AH (Tables 4 and 5). 2,14 Target-organ assessment should be performed in all children and adolescents with stage 1 and 2 AH. Sleep study by use of polysomnography or home respiratory polygraphy is indicated for children and adolescents with sleep disorders detected on anamnesis. 2 To investigate secondary AH, see Chapter 12. Table 5 shows some tests for children and adolescents suspected of having secondary AH.

Therapeutic aspects
In children and adolescents with confirmed AH, therapeutic management is guided by the AH etiology definition, CV risk assessment, and TOD characterization.

Nonpharmacological management
Nonpharmacological management should be introduced to all pediatric patients with BP levels above the 90 th percentile. 2 (GR: IIa; LE: C). It includes body weight loss, a physical exercise program, and dietary intervention. 2 Body weight reduction yields good results in the treatment of obese hypertensive children, 19 similarly to physical exercise, which has better effect on SBP levels. 19 Regular aerobic activity is recommended as follows: moderate-intensity physical exercise, 30-60 minutes/day, if possible, every day. Children with AH can practice resistance or localized training, except for weight lifting. Competitive sports are not recommended for patients with uncontrolled stage 2 AH. 20 Dietary intervention can comprise sodium restriction, 21 and potassium and calcium supplementation; the efficacy in that population, however, is yet to be proven. 22

Pharmacological management
Pharmacological therapy should be initiated for children with symptomatic AH, secondary AH, presence of TOD, types 1 and 2 DM, CKD and persistent AH nonresponsive to nonpharmacological therapy. 2 (GR: IIa; LE: B). The treatment is aimed at BP reduction below the 95 th percentile in non-complicated AH, and BP reduction below the 90 th percentile in both complicated AH, characterized by TOD and comorbidities (DM, CKD), and secondary AH. 2 (GR: IIa; LE: C). The treatment should begin with a first-line antihypertensive agent, whose dose should be optimized, and, if target BP level is not attained, other pharmacological groups should be added in sequence. A recent systematic review 23 has identified neither a randomized study assessing the efficacy of antihypertensive drugs on TOD, nor any consistent dose-response relationship with any drug class assessed.
The adverse events associated with the use of antihypertensive agents for children and adolescents have been usually of mild intensity, such as headache, dizziness, and upper respiratory tract infections. All classes of antihypertensive drugs seem safe, at least in the short run. 23 The only randomized, double-blind, controlled study, by Schaefer et al., comparing the efficacy and safety of drugs of parallel groups and assessing hypertensive children on enalapril or valsartan, has shown comparable results regarding the efficacy and safety of both drugs. 24 In secondary AH, the antihypertensive drug choice should be in consonance with the pathophysiological • When using the oscillometric device, it requires validation. • Detection of AH by use of the oscillometric device requires confirmation with auscultation. • Use appropriate cuff size; air bag width: 40% of arm circumference in the middle point between the acromion and olecranon, and air bag length: 80-100% of arm circumference.
Special clinical conditions can be managed with more specific hypotensive agents for the underlying disease. Patients with catecholamine-producing tumors can be initially alpha-blocked with phenoxybenzamine, or prazosin if the former is not available, followed by the careful addition of a BB. After BP control and in the absence of kidney or heart dysfunction, a sodium-rich diet  Table 7 shows the most frequently used drugs in pediatric HE. 38