Obesity Hypertension in Adolescents: Epidemiology, Evaluation, and Management

Abstract

The prevalence of hypertension among all adolescents is approximately 3.5%, with somewhat higher rates of prehypertension. Obesity affects approximately 20% of adolescents in the United States, and the prevalence of hypertension is much higher among obese adolescents compared with nonobese adolescents. As in other populations, the evaluation of elevated blood pressure in obese adolescents should begin with a confirmation of the blood pressure elevation, followed by a focused diagnostic work‐up to detect possible secondary causes of hypertension. Primary therapy for obesity‐related hypertension in adolescents begins with weight loss, and may include antihypertensive medications if target‐organ damage or other indications for drug therapy are present. The emphasis of management should be reduction of future cardiovascular risk.

J Clin Hypertens (Greenwich). 2011;13:323–331. ©2011 Wiley Periodicals, Inc.

The definition of hypertension in adults is based on outcome data that demonstrate a strong relationship between a blood pressure (BP) level above 140/90 mm Hg and risk for subsequent cardiovascular (CV) events. Similar data are not available in adolescents. Therefore, hypertension is defined somewhat differently in adolescents than in adults, depending on the age of the adolescent (Table I). In the adolescent 18 years or older, recommendations of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure ¹ should be followed, which defines hypertension as a BP >140/90 mm Hg on ≥2 office visits. In the adolescent younger than 18 years, the recommendations of the National High Blood Pressure Education Program (NHBPEP) Working Group on High Blood Pressure in Children and Adolescents ² should be used, which defines hypertension as an average systolic and/or diastolic BP that is ≥95th percentile for sex, age, and height on ≥3 occasions. Normative BP values for adolescents younger than 18 years can be found in Table II and Table III.

Table I.

 Classification of Hypertension in Adolescents

Blood Pressure Classification	Adolescents Younger than 18 y	Adolescents 18 y and Older
Normal	SBP and DBP <90th percentile	SBP <120 mm Hg and DBP <80 mm Hg
Prehypertension	SBP or DBP 90th–95th percentile; or if BP is >120/80 mm Hg even if <90th percentile	SBP 120–139 mm Hg or DBP 80–89 mm Hg
Stage 1 hypertension	SBP or DBP ≥95th–99th percentile plus 5 mm Hg	SBP 140–159 mm Hg or DBP 90–99 mm Hg
Stage 2 hypertension	SBP or DBP >99th percentile plus 5 mm Hg	SBP ≥160 mm Hg or DBP ≥100 mm Hg

Abbreviations: DBP, diastolic blood pressure; SBP, systolic blood pressure. Adapted with permission. ¹ , ^{2 ,2}

Table II.

 Blood Pressure Levels for Adolescent Boys Younger than 18 y by Age and Height Percentile

Age, y	BP Percentile	Systolic BP, mm Hg							Diastolic BP, mm Hg
		Percentile of Height							Percentile of Height
		5th	10th	25th	50th	75th	90th	95th	5th	10th	25th	50th	75th	90th	95th
10	50th	97	98	100	102	103	105	106	58	59	60	61	61	62	63
	90th	111	112	114	115	117	119	119	73	73	74	75	76	77	78
	95th	115	116	117	119	121	122	123	77	78	79	80	81	81	82
	99th	122	123	125	127	128	130	130	85	86	86	88	88	89	90
11	50th	99	100	102	104	105	107	107	59	59	60	61	62	63	63
	90th	113	114	115	117	119	120	121	74	74	75	76	77	78	78
	95th	117	118	119	121	123	124	125	78	78	79	80	81	82	82
	99th	124	125	127	129	130	132	132	86	86	87	88	89	90	90
12	50th	101	102	104	106	108	109	110	59	60	61	62	63	63	64
	90th	115	116	118	120	121	123	123	74	75	75	76	77	78	79
	95th	119	120	122	123	125	127	127	78	79	80	81	82	82	83
	99th	126	127	129	131	133	134	135	86	87	88	89	90	90	91
13	50th	104	105	106	108	110	111	112	60	60	61	62	63	64	64
	90th	117	118	120	122	124	125	126	75	75	76	77	78	79	79
	95th	121	122	124	126	128	129	130	79	79	80	81	82	83	83
	99th	128	130	131	133	135	136	137	87	87	88	89	90	91	91
14	50th	106	107	109	111	113	114	115	60	61	62	63	64	65	65
	90th	120	121	123	125	126	128	128	75	76	77	78	79	79	80
	95th	124	125	127	128	130	132	132	80	80	81	82	83	84	84
	99th	131	132	134	136	138	139	140	87	88	89	90	91	92	92
15	50th	109	110	112	113	115	117	117	61	62	63	64	65	66	66
	90th	122	124	125	127	129	130	131	76	77	78	79	80	80	81
	95th	126	127	129	131	133	134	135	81	81	82	83	84	85	85
	99th	134	135	136	138	140	142	142	88	89	90	91	92	93	93
16	50th	111	112	114	116	118	119	120	63	63	64	65	66	67	67
	90th	125	126	128	130	131	133	134	78	78	79	80	81	82	82
	95th	129	130	132	134	135	137	137	82	83	83	84	85	86	87
	99th	136	137	139	141	143	144	145	90	90	91	92	93	94	94
17	50th	114	115	116	118	120	121	122	65	66	66	67	68	69	70
	90th	127	128	130	132	134	135	136	80	80	81	82	83	84	84
	95th	131	132	134	136	138	139	140	84	85	86	87	87	88	89
	99th	139	140	141	143	145	146	147	92	93	93	94	95	96	97

Abbreviation: BP, blood pressure. Adapted with permission. ²

Table III.

 Blood Pressure Levels for Adolescent Girls Younger than 18 y by Age and Height Percentile

Age, y	BP Percentile	Systolic BP, mm Hg							Diastolic BP, mm Hg
		Percentile of Height							Percentile of Height
		5th	10th	25th	50th	75th	90th	95th	5th	10th	25th	50th	75th	90th	95th
10	50th	98	99	100	102	103	104	105	59	59	59	60	61	62	62
	90th	112	112	114	115	116	118	118	73	73	73	74	75	76	76
	95th	116	116	117	119	120	121	122	77	77	77	78	79	80	80
	99th	123	123	125	126	127	129	129	84	84	85	86	86	87	88
11	50th	100	101	102	103	105	106	107	60	60	60	61	62	63	63
	90th	114	114	116	117	118	119	120	74	74	74	75	76	77	77
	95th	118	118	119	121	122	123	124	78	78	78	79	80	81	81
	99th	125	125	126	128	129	130	131	85	85	86	87	87	88	89
12	50th	102	103	104	105	107	108	109	61	61	61	62	63	64	64
	90th	116	116	117	119	120	121	122	75	75	75	76	77	78	78
	95th	119	120	121	123	124	125	126	79	79	79	80	81	82	82
	99th	127	127	128	130	131	132	133	86	86	87	88	88	89	90
13	50th	104	105	106	107	109	110	110	62	62	62	63	64	65	65
	90th	117	118	119	121	122	123	124	76	76	76	77	78	79	79
	95th	121	122	123	124	126	127	128	80	80	80	81	82	83	83
	99th	128	129	130	132	133	134	135	87	87	88	89	89	90	91
14	50th	106	106	107	109	110	111	112	63	63	63	64	65	66	66
	90th	119	120	121	122	124	125	125	77	77	77	78	79	80	80
	95th	123	123	125	126	127	129	129	81	81	81	82	83	84	84
	99th	130	131	132	133	135	136	136	88	88	89	90	90	91	92
15	50th	107	108	109	110	111	113	113	64	64	64	65	66	67	67
	90th	120	121	122	123	125	126	127	78	78	78	79	80	81	81
	95th	124	125	126	127	129	130	131	82	82	82	83	84	85	85
	99th	131	132	133	134	136	137	138	89	89	90	91	91	92	93
16	50th	108	108	110	111	112	114	114	64	64	65	66	66	67	68
	90th	121	122	123	124	126	127	128	78	78	79	80	81	81	82
	95th	125	126	127	128	130	131	132	82	82	83	84	85	85	86
	99th	132	133	134	135	137	138	139	90	90	90	91	92	93	93
17	50th	108	109	110	111	113	114	115	64	65	65	66	67	67	68
	90th	122	122	123	125	126	127	128	78	79	79	80	81	81	82
	95th	125	126	127	129	130	131	132	82	83	83	84	85	85	86
	99th	133	133	134	136	137	138	139	90	90	91	91	92	93	93

Abbreviation: BP, blood pressure. Adapted with permission. ²

On the other hand, the definition of prehypertension is the same in adolescents of all ages, namely a BP reading >120/80 mm Hg. This is because the cut‐point for normal BP in childhood, defined as a BP reading <90th percentile, is essentially reached for systolic BP by age 12 years in both boys and girls. ² For all adolescents, the severity of hypertension should be staged once an individual is diagnosed with hypertension (Table I). Staging the severity of hypertension is helpful in guiding subsequent evaluation and management.

Based on the 95th percentile to define hypertension, the expected prevalence of hypertension in adolescents would be approximately 5%. However, due to accommodation and regression to the mean with repeat measurements, the prevalence of hypertension in adolescents is actually much lower, with screening studies conducted in the 1970s to 1990s demonstrating prevalences of 1% to 2% using repeat measurements. More recent data from large samples of healthy adolescents show that the rates of hypertension and prehypertension in adolescents are greater than expected and are increasing. Using electronic medical record data from well child visits on more than 14,000 primary care children and adolescents, Hansen and coworkers ³ applied the above criteria for hypertension and prehypertension. With the advantage of data on repeat BP measurements, the prevalence of hypertension was 3.6% and the prevalence of prehypertension was 3.4%. A similar prevalence of hypertension was reported by McNiece and coworkers ⁴ in a study on high school students. Using repeat BP measurements in patients with an elevated initial BP measurement, these investigators reported a hypertension prevalence of 3.2% and a prehypertension prevalence of 15.7% in adolescents. The presence of obesity was associated with much higher rates of hypertension in both of these reports. In the report on high school students by McNiece and coworkers, ⁴ the prevalence of hypertension and prehypertension combined was more than 30% in obese adolescent boys and 23% to 30% in obese adolescent girls depending on ethnicity. Other studies on asymptomatic, otherwise healthy adolescents report similar rates of high BP in obese adolescents. ⁵ , ⁶

The strong relationship of high BP with obesity in adolescence along with the childhood obesity epidemic indicate that the population prevalence of adolescent hypertension will be increasing, and there is already evidence that this trend is underway. Muntner and coworkers ⁷ examined BP levels in children and adolescents from data in two more recent National Health and Nutrition Examination Surveys (NHANES) studies and identified a significant increase in both systolic and diastolic BP level. A subsequent analysis of data on the same two NHANES databases detected an overall increase in the prevalence of childhood hypertension from 2.7% in the 1988–1994 survey to 3.7% in the 1999–2002 survey period. ⁸ Both reports verified that the increase in BP level and prevalence of hypertension among adolescents in the United States is largely due to the increasing prevalence of obesity. These data indicate that obesity‐associated hypertension and prehypertension in adolescence is a major public health problem and a condition that is likely to contribute substantially to future CV disease.

While reasonably good data are now available on the prevalence of hypertension in adolescence, there is also evidence that BP measured in adolescence predicts future BP. Adolescents with BP levels in the higher portion of the BP distribution curve tend to maintain that position over time, which is indicative of BP tracking. ⁹ , ¹⁰ , ¹¹ There are also reports that link higher BP level in childhood with hypertension in early adulthood. ² However, data on the annual incidence of hypertension in adolescence are limited. Within the childhood BP database maintained by the NHBPEP, a segment of adolescents had repeat BP measurements at intervals of 2 and 4 years. An analysis of these data determined that among adolescents with prehypertension, 14% had hypertension 2 years later, suggesting that there could be an approximate incidence of adolescent hypertension of 7% per year among those with prehypertension. These data have limitations because they are based on a single BP measurement for BP classification. However, among adolescents with prehypertension and hypertension combined, on the basis of a single BP measurement, 68% of boys and 43% of girls had prehypertension or hypertension 2 years later. ¹² Thus, even a single elevated BP measurement in an adolescent raises the risk of having persistent BP elevation.

Nutrition

The usual intake of dietary sodium among children, as well as among adults, in the United States and other westernized countries is far in excess of nutritional requirements. The high sodium intake is largely due to secular changes in diet patterns with greater consumption of processed foods. The benefits of lowering sodium intake in adult hypertensive patients have been established and epidemiologic data support of population benefit with reductions in dietary sodium. The association of sodium intake with BP in children has been more difficult to define. A meta‐analysis on reported studies conducted between 1981 and 2004 that examined the effect of dietary sodium reduction on BP in children and adolescents was performed by He and coworkers. ¹³ In combining the results of 10 separate studies, these investigators found that a 54% reduction in sodium intake was associated with a modest (2.47 mm Hg) but significant reduction in systolic BP. Although the absolute change in BP with sodium reduction may seem insignificant for an individual patient, the population effect is likely to be greater, especially considering the lifelong burden of high sodium intake on BP. An obvious effect of high salt intake is an increase in thirst. The same investigators ¹⁴ conducted another study to compare sodium intake with the volume and type of beverage consumption in children in Great Britain. A statistically significant correlation (P<.001) of sodium intake with the total volume of beverage consumption was identified. Moreover, a high consumption of sugary beverages was also found. These results indicate that excess dietary sodium intake may not only raise BP, but also contribute to childhood obesity through effecting thirst that is then satisfied by increased consumption of sugary beverages.

It is known that other dietary nutrients confer health benefits. The now classic Dietary Approaches to Stop Hypertension (DASH) study demonstrated, in adults with high BP, the BP‐lowering benefits of a diet that was high in fresh fruits, vegetables, whole grains, and low‐fat dairy products. ¹⁵ Although similar diet trials have not been conducted in adolescents, it is generally accepted that adolescents with high BP may benefit from diets that contain more fresh fruits, vegetables, fiber, and dairy, while avoiding excessive intakes of high‐sodium processed foods. ² This recommendation is supported by a recent report by Couch and coworkers, ¹⁶ who compared, in an outpatient setting, a DASH diet tailored to children and adolescents to standard nutrition counseling in 57 children and adolescents with hypertension or prehypertension. Among those assigned to the DASH diet, there was a significantly greater reduction in systolic BP compared with those who received standard diet counseling. Although this report is described as a pilot study, the results support both the need for further investigation and the need for current recommendations to increase intake of fruits, vegetables, fiber, and dairy in the diets of adolescents.

Evaluation of the Hypertensive Adolescent

As in adults, evaluation of the hypertensive adolescent should begin with confirmation that the BP is truly elevated and should then proceed through focused laboratory and imaging studies. Since secondary causes of hypertension are more common in the pediatric age group than in adults, attention should be paid to detecting underlying conditions that may be causing the elevated BP. The initial evaluation should also include an assessment for hypertensive target organ damage, the presence or absence of which will help guide therapy. ²

Confirmation of Elevated BP

It has long been established that BP in childhood is more labile than in adults—even children with secondary causes of hypertension have been shown to demonstrate significant variability in office BP readings. ¹⁷ Additionally, the phenomenon of regression to the mean has been demonstrated to be common, even among those thought to be hypertensive and therefore deemed eligible for inclusion in antihypertensive drug trials. ¹⁸ Thus, it is crucial to confirm that the adolescent’s BP is truly elevated before making the diagnosis of hypertension and embarking on a diagnostic evaluation.

The first step is to ensure that BP is being measured properly. The NHBPEP Working Group recommended auscultation as the preferred method of BP measurement in the young, and specifically stated that elevated readings obtained using oscillometric devices should be repeated by auscultation. ² Recent data from pediatric hypertension clinics demonstrate that readings obtained using oscillometric devices are not comparable to those obtained by auscultation, ¹⁹ thereby confirming the recommendations of the Working Group.

The size of the cuff used in measuring BP in adolescents is critical. The bladder of the cuff should encircle 80% to 100% of the arm circumference or the reading may be falsely elevated. Optimally, the arm circumference should first be measured with a tape measure, and then an appropriately sized cuff chosen. Recent data from NHANES have shown that, in conjunction with the childhood obesity epidemic, arm sizes of children have increased, meaning that more adolescents will require use of a “large adult” or even “thigh” cuff to obtain an accurate BP reading. ²⁰

With these issues in mind, it is usually recommended that even for pediatric patients referred for evaluation of suspected hypertension, additional office BP measurements should be obtained to confirm the hypertension. ²¹ This can be done over a period of time, depending on the severity of the BP elevation and the presence or absence of symptoms. ² Additionally, consideration should be given to performance of ambulatory BP monitoring (ABPM) for further confirmation of hypertension and to identify patients with white coat hypertension (WCH). WCH has been shown to be present in 30% to 40% of children and adolescents referred for evaluation of suspected hypertension, depending on the diagnostic criteria used. ²² Home BP measurement has also been proposed to uncover WCH in pediatric patients, but uncertainty over normal values in the young makes this a less reliable method than ABPM.

Differential Diagnosis

It is helpful to have a potential differential diagnosis in mind before starting the diagnostic evaluation. Whereas young children are likely to have secondary hypertension, in adolescents, it is now known that primary hypertension accounts for the majority of cases. This was clearly seen in a 1992 study by Wyszynska and coworkers ²³ of 1025 children referred to a Polish children’s hospital for evaluation of hypertension (defined as BP persistently >95th percentile). Overall, 45% of their study population had primary hypertension and 55% secondary hypertension. Among adolescents (aged 15–18 years), who comprised 60% of those studied, 75% were found to have primary hypertension. Similarly, in a recent series from the University of Michigan ²⁴ of 92 adolescents with confirmed hypertension, 64% had no identifiable underlying cause for their hypertension, while the rest had secondary causes.

Certain factors increase the likelihood of primary hypertension in adolescence, including a family history of hypertension and obesity. Offspring of hypertensive parents have been found to have higher BPs and an increased prevalence of other CV risk factors. ²⁵ , ²⁶ The prevalence of a positive family history of hypertension in children and adolescents with primary hypertension has recently been reported to be in excess of 80%. ²⁴ Thus, a family history of hypertension (or of other CV disease such as stroke) increases the likelihood of a diagnosis of primary hypertension, especially when the results of initial diagnostic studies (see below) are normal. Obesity is more common among pediatric patients with primary hypertension than those with secondary hypertension and is associated with an earlier age of onset of hypertension, independent of family history. ²⁷

History and Physical Examination

Evaluation of the hypertensive adolescent should begin with a comprehensive medical history and physical examination. The history should begin with asking whether any symptoms suggestive of hypertension are present, such as headaches, dizziness, diplopia, vomiting, or epistaxis. The interview should then focus on uncovering symptoms of other underlying disorders, including symptoms of possible renal disease, heart disease, or diseases affecting other organ systems. ² The medical history should include questions about recent as well as chronic illnesses, prior hospitalizations or episodes of trauma, recurrent urinary tract infections or unexplained fevers, and neonatal history. Family history of hypertension, diabetes, renal disease, and other CV disease (hyperlipidemia, myocardial infarction at an early age) should be elicited. Finally, it is important to ask about over‐the‐counter, prescription, and illicit drug use, as many substances commonly used by adolescents can either cause or exacerbate hypertension.

Physical examination begins by obtaining the patient’s weight and height so that growth percentiles can be plotted and body mass index calculated. BPs should be obtained in both upper extremities in the seated position and in at least one arm and one leg in the supine position in order to rule out aortic coarctation. As with the history, the rest of the physical examination should focus on uncovering signs of specific underlying disorders that may be causing the adolescent’s hypertension. ² In obese adolescents, there may be signs of insulin resistance such as acanthosis nigricans, or in girls, findings suggestive of polycystic ovarian syndrome such as hirsutism. The physical examination may also provide clues as to the severity/chronicity of the patient’s hypertension, such as left ventricular hypertrophy (signified by an apical heave) or hypertensive retinopathy.

Diagnostic Testing

Patients with confirmed hypertension should then undergo diagnostic testing to follow up on findings from the history and physical examination and to assess for other coexisting CV risk factors. It is typical to obtain a basic set of screening studies in all patients, including a urinalysis, serum chemistries (electrolytes, serum urea nitrogen/creatinine and calcium), fasting lipid panel, and fasting glucose. Dyslipidemia can be present in adolescents with elevated BP amd recent studies have confirmed this association. ²⁴ , ²⁸ The typical pattern is normal to slightly elevated total cholesterol with low HDL cholesterol and elevated triglycerides. This pattern is similar to the dyslipidemia that occurs in type 2 diabetes and may reflect a component of insulin resistance, even in nonobese hypertensive patients. Impaired glucose tolerance also occurs frequently in obese hypertensive children, typically as part of the metabolic syndrome. ²⁹ Other studies have demonstrated that these CV risk factors may be associated with the early development of atherosclerosis in the young. ³⁰ It is therefore reasonable to screen for these risk factors/comorbidities when evaluating hypertensive adolescents. Identification of multiple CV risk factors at an early age may, in turn, permit institution of measures aimed at prevention of adult CV disease.

Plasma renin activity (PRA) and aldosterone are sometimes also included in the initial set of diagnostic studies, especially when the patient’s hypertension is severe or if both systolic and diastolic hypertension are present. Two recent studies have demonstrated a relationship between BP levels and PRA and between PRA and the degree of obesity in obese adolescents, ²⁴ although further study is needed to better delineate how obesity affects regulation of the renin‐aldosterone system in the young.

Given the high likelihood of primary hypertension in adolescence, renal ultrasounds, which are routinely obtained in younger hypertensive patients, could be omitted in adolescents with stage 1 hypertension if the screening studies are normal and if other features of primary hypertension are present, including obesity, a positive family history, and isolated systolic hypertension. A renal ultrasound should be obtained in adolescents with stage 2 hypertension, with abnormal screening studies, or with diastolic hypertension. Additional imaging studies, including renal angiography, nuclear renal scans, and voiding cystourethrograms should be obtained only as indicated based on the results of the history, physical examination, and initial diagnostic studies.

Assessment for Hypertensive Target Organ Damage

An important component in the evaluation of the hypertensive adolescent is to determine whether there is hypertensive target organ damage present, which is an indication for use of antihypertensive medications. ² Left ventricular hypertrophy (LVH) is the most common and most easily identified target organ effect of hypertension in adolescents. Recent studies have established a prevalence of LVH in hypertensive children and adolescents as high as 30% to 40%. ²¹ , ²² , ³¹ , ³³ Although the adverse effects of LVH seen in adults such as sudden cardiac death have not been proven to occur in hypertensive children, LVH is considered an important CV risk factor in hypertensive children. Treatment with anti‐hypertensive medication is recommended in hypertensive children and adolescents with LVH. Given the high prevalence of LVH, 2‐dimensional and M‐mode echocardiography should be obtained to assess for the presence of hypertensive target organ damage. ² Left ventricular mass should be indexed to height to correct for the effect of obesity.

Other hypertension‐associated target organ changes have recently been demonstrated in hypertensive children and adolescents, including retinal changes, increased carotid intimal‐medial thickness (cIMT) and microalbuminuria. ³⁴ In population studies in children, an association of retinal vascular structure with systolic BP has been described. ³⁴ Recent reports describe greater cIMT in hypertensive adolescents compared with normotensive adolescents. ⁵ , ³⁶ As in hypertensive adults, increased cIMT in the young is associated with obesity and LVH. ³⁶ With respect to microalbuminuria, Assadi ³⁷ reported that treating microalbuminuria in children with primary hypertension with renoprotective therapy was associated with LVH regression. Additionally, Lubrano and coworkers ³⁸ have described an association of albuminuria with BP load on ABPM in children with prehypertension. These recent reports indicate that hypertensive target organ changes in adolescents with high BP may be more prevalent than expected. However, until more clinical data are available and measurement methodologies have been standardized in children and adolescents, echocardiographic measurement of left ventricular mass remains the best study for assessment of target organ damage in hypertensive adolescents. ²

Approach to Therapy

Nonpharmacologic Approaches

Weight loss, aerobic exercise, and dietary modifications have all been shown to successfully reduce BP in children and adolescents and are therefore considered primary treatment, ² especially in those with obesity‐related hypertension. Studies in obese adolescents have demonstrated that modest weight loss not only decreases BP but also improves other CV risk factors such as dyslipidemia and insulin resistance. ³⁹ , ⁴⁰ , ⁴¹ In studies where a reduction in body mass index of about 10% was achieved, short‐term reductions in BP were in the range of 8 mm Hg to 12 mm Hg. Unfortunately, weight loss is difficult and frequently unsuccessful. In this context, family‐based interventions should be considered, as they have been shown to be reasonably successful long‐term. ⁴²

Aerobic forms of exercise are recommended for adolescents with hypertension. Supervised exercise training during 3 to 6 months has been shown to result in a reduction of 6 mm Hg to 12 mm Hg for systolic BP and 3 mm Hg to 5 mm Hg for diastolic BP. ⁴³ Increasing physical activity may not only reduce BP, but can help with weight loss and/or maintenance. It is recommended that the amount of time spent in sedentary activities such as television viewing should be restricted to <2 h/d. ⁴⁴ However, as with weight loss, cessation of regular exercise is generally promptly followed by a rise in BP to pre‐exercise levels. Furthermore, exercise alone is unlikely to be sufficient to control BP and should probably be combined with dietary changes for best results. The combination of dietary changes and exercise training may also improve vascular function in addition to reducing BP. ⁴⁵

Dietary modification should be incorporated into the management of hypertension in all adolescents, especially adolescents with primary hypertension. The dietary sodium intakes of adolescents, at least in the United States, far exceed any nutritional requirement for sodium. A large portion of the excess sodium intake is attributed to consumption of processed food products and “fast” foods. Dietary sodium restriction may have an important role in treatment of overweight hypertensive adolescents, a substantial proportion of whom are likely to be salt‐sensitive. ⁴⁶ To lower sodium intake, adolescents with high BP should be encouraged to avoid, or at least reduce, consuming processed foods and salty snacks. It is now recognized that a diet that both limits sodium and is enriched in multiple nutrients including calcium, magnesium, potassium, and other nutrients may be more effective in treatment of hypertension than a diet that only restricts sodium. An example of such a diet is the so‐called DASH diet, which has been shown to have an antihypertensive effect in adults with hypertension, ⁴⁷ as well as in a pilot study in hypertensive adolescents. ¹⁶ Thus, the DASH eating plan is logical to apply to the treatment of hypertensive adolescents, especially if accompanied by counseling from a pediatric dietitian. The DASH diet also lowers dietary fat intake, an important benefit given the frequent presence of dyslipidemia in hypertensive adolescents.

These nonpharmacologic approaches are recommended as first‐line treatment of hypertension in adolescents, especially in those who are obese. To be more effective, these measures should be implemented with nutrition education, family involvement, and long‐term support. They should be applied even if there is an established indication for initiation of antihypertensive medications, as successful lifestyle changes can complement the efficacy of pharmacologic treatment.

Use of Antihypertensive Medications

Despite weight loss, exercise, and dietary changes, antihypertensive medications will be needed in some hypertensive adolescents to achieve the goal BP. The current recommendations on indications for antihypertensive pharmacologic therapy in adolescents include the following criteria:

• • Stage 2 hypertension
• • Symptomatic hypertension
• • Secondary hypertension
• • Hypertensive target organ damage
• • Diabetes (types 1 and 2)
• • Persistent hypertension despite nonpharmacologic measures.

Most of these indications represent situations in which BP reduction is likely to be of benefit in the treatment of another condition: for example, reduction of BP in patients with diabetes is an important strategy to slow the development of diabetic nephropathy, and reduction of BP in patients with chronic kidney disease has been shown to slow the rate of progression toward end‐stage renal disease. Only the last indication is somewhat unclear, as the length of time needed to see an effect of lifestyle changes may vary significantly from patient to patient. At the very least, hypertensive adolescents who either do not comply with or do not respond to a reasonable (6–12 month) trial of nonpharmacologic measures should probably be prescribed antihypertensive medications due to the likely risk of development of hypertensive target organ damage in these patients. Repeat assessment for LVH and other CV risk factors may be helpful in determining how long to continue lifestyle measures alone.

Legislative initiatives in the United States and Europe have led to an increase in pediatric trials of antihypertensive medications and an increase in the number of medications with specific pediatric labeling, which together provide the clinician with much useful information to guide prescribing when medications are indicated. What is still lacking is guidance on the preferred class of antihypertensive medications for initial drug treatment in hypertensive adolescents. Adult clinical practice guidelines such as the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) have clear recommendations based on clinical trial evidence, but a similar evidence base is lacking for adolescents, as studies comparing different classes of antihypertensive agents have not been conducted in the young. Until data are available to differentiate the advantages and disadvantages of different classes of antihypertensive medications in adolescents, it is reasonable to consider several classes of agents, including diuretics, β‐blockers, angiotensin‐converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and calcium channel blockers as potentially acceptable first‐line agents. Recommended doses for use in hypertensive adolescents can be found in Table IV.

Table IV.

 Suggested Doses of Antihypertensive Medications for Use in Adolescents

Class	Drug	Starting Dose	Interval	Maximum Dosea
Aldosterone receptor antagonists	Eplerenone	25 mg/d	QD‐BID	100 mg/d
	Spironolactoneb	1 mg/kg/d	QD‐BID	3.3 mg/kg/d up to 100 mg/d
Angiotensin‐converting enzyme inhibitors	Benazeprilb	0.2 mg/kg/d up to 10 mg/d	QD	0.6 mg/kg/d up to 40 mg/d
	Captoprilb	0.3–0.5 mg/kg/dose	BID–TID	6 mg/kg/d up to 450 mg/d
	Enalaprilb	0.08 mg/kg/d	QD	0.6 mg/kg/d up to 40 mg/d
	Fosinopril	0.1 mg/kg/d up to 10 mg/d	QD	0.6 mg/kg/d up to 40 mg/d
	Lisinoprilb	0.07 mg/kg/d up to 5 mg/d	QD	0.6 mg/kg/d up to 40 mg/d
	Quinapril	5–10 mg/d	QD	80 mg/d
Angiotensin receptor blockers	Candesartan	1–6 y, 0.2 mg/kg/d; 6–17 y, <50 kg 4–8 mg once daily >50 kg 8–16 mg once daily	QD	1–6 y, 0.4 mg/kg; 6–17 y, <50 kg 16 mg once daily, >50 kg 32 mg once daily
	Losartanb	0.75 mg/kg/d up to 50 mg/d	QD	1.4 mg/kg/d up to 100 mg/d
	Olmesartan	20–<35 kg 10 mg once daily; ≥35 kg 20 mg once daily	QD	20–<35 kg 20 mg once daily ≥35 kg 40 mg once daily
	Valsartanb	6–17 y, 1.3 mg/kg/d up to 40 mg/d; <6 y: 5–10 mg/d	QD	6–17 y, 2.7 mg/kg/d up to 160 mg/d; <6 y: 80 mg/d
α‐ and β‐Adrenergic antagonists	Labetalolb	2–3 mg/kg/d	BID	10–12 mg/kg/d up to 1.2 g/d
	Carvedilol	0.1 mg/kg/dose up to 12.5 mg BID	BID	0.5 mg/kg/dose up to 25 mg BID
β‐Adrenergic antagonists	Atenololb	0.5–1 mg/kg/d	QD–BID	2 mg/kg/d up to 100 mg/d
	Bisoprolol/HCTZ	0.04 mg/kg/d up to 2.5/6.25 mg/d	QD	10/6.25 mg/d
	Metoprolol	1–2 mg/kg/d	BID	6 mg/kg/d up to 200 mg/d
	Propranolol	1 mg/kg/d	BID–TID	16 mg/kg/d up to 640 mg/d
Calcium channel blockers	Amlodipineb	0.06 mg/kg/d	QD	0.3 mg/kg/d up to 10 mg/d
	Felodipine	2.5 mg/d	QD	10 mg/d
	Isradipineb	0.05–0.15 mg/kg/dose	TID–QID	0.8 mg/kg/d up to 20 mg/d
	Extended‐release nifedipine	0.25–0.5 mg/kg/d	QD–BID	3 mg/kg/d up to 120 mg/d
Central α‐agonist	Clonidineb	5–10 mcg/kg/d	BID‐TID	25 mcg/kg/d up to 0.9 mg/d
Diuretics	Amiloride	5–10 mg/d	QD	20 mg/d
	Chlorthalidone	0.3 mg/kg/d	QD	2 mg/kg/d up to 50 mg/d
	Furosemide	0.5–2.0 mg/kg/dose	QD‐BID	6 mg/kg/d
	HCTZ	0.5–1 mg/kg/d	QD	3 mg/kg/d up to 50 mg/d
Vasodilators	Hydralazine	0.25 mg/kg/dose	TID–QID	7.5 mg/kg/d up to 200 mg/d
	Minoxidil	0.1–0.2 mg/kg/d	BID–TID	1 mg/kg/d up to 50 mg/d

Abbreviations: BID, twice daily; HCTZ, hydrochlorothiazide; QD, once daily; QID, 4 times daily; TID, 3 times daily. ^aThe maximum recommended adult dose should never be exceeded. ^bInformation on preparation of a stable extemporaneous suspension is available for these agents.

There are certain clinical situations in which specific classes of antihypertensive agents are indicated. The best example of this would be patients with underlying chronic kidney disease, in whom ACE inhibitors or ARBs are preferred due to their beneficial effects on slowing progression. Similarly, in hypertensive adolescents with the metabolic syndrome, the effect of the antihypertensive drug on glucose metabolism needs to be considered. ⁴⁸ As with adults, adherence to prescribed therapy is an important issue that should be considered in choosing an antihypertensive medication. If BP control can be achieved with a single, once‐daily agent, the likelihood of adherence to the medication is greater. The use of combination preparations can improve compliance when >1 drug is needed to achieve the goal BP.

A “stepped‐care” approach to the use of antihypertensive medications in the young continues to be recommended. ² Stepped care allows individualization of therapy and ongoing assessment of efficacy and adverse effects. Given the new US Food and Drug Administration–approved pediatric labeling for many antihypertensive agents, those antihypertensive drugs that are labeled for pediatric use are preferred for most hypertensive adolescents.

Treatment goals for hypertensive adolescents should take into consideration the presence of comorbid conditions. ² For patients with uncomplicated primary hypertension and no hypertensive target organ damage, goal BP should be <95th percentile for age, sex, and height. For adolescents with secondary hypertension, diabetes, or hypertensive target organ damage, goal BP should be <90th percentile for age, sex, and height. These goals are consistent with current recommendations for therapy of hypertensive adults. ¹ The European Society of Hypertension has recently issued updated guidelines ⁴⁹ for management of childhood hypertension that recommend an even lower goal of <75th percentile for patients with chronic kidney disease.

The management of hypertension in adolescents does not end when medications are prescribed. Hypertensive adolescents should be followed‐up at regular intervals to ensure that the desired BP goal has been reached, to assess adherence to therapy, and to monitor for medication‐related adverse effects. Continuation of nonpharmacologic measures should be encouraged to augment BP control. Repeat laboratory studies should be obtained periodically, especially fasting lipids and glucose in obese adolescents and electrolytes/serum urea nitrogen/creatinine in those treated with diuretics, ACE inhibitors, or ARBs. Female patients receiving ACE inhibitors or ARBs should be counseled to use effective contraception due to the risks of ACE inhibitor fetopathy.

Conclusions

The prevalence of primary hypertension among adolescents has increased, largely due to the childhood obesity epidemic. Other risk factors including dyslipidemia and abnormal glucose tolerance are frequently present in adolescents with obesity‐associated hypertension. Recent reports have also demonstrated that intermediate markers of target organ damage such as LVH can also be detected in adolescents with hypertension. Although long‐term outcome data are still limited, the emerging data indicate that adolescents with hypertension plus other metabolic risk factors are at high risk for accelerated CV disease. Careful detection, clinical evaluation, and management of obesity‐associated hypertension in adolescents are important to modify risk.