Approach to Diagnosis and Management of Pediatric Hypertension in an Outpatient Setting

Hypertensive children are likely to become hypertensive adults

During early childhood, individual BP levels can vary between measurements. However, around 8–9 years of age, BP levels within individuals tend to track along the same percentile. Evidence suggests that primary pediatric HTN predicts adult HTN, with a tracking coefficient of at least 0.4.²⁵ Children with higher BP levels are more likely to carry them into adulthood. This persistence raises the risk for subsequent cardiovascular diseases (CVD) in adulthood.²⁵

Target organ damage in children with HTN

Strong evidence backs the association between pediatric HTN and adverse subclinical cardiovascular outcomes or target organ damage. In adults, these subclinical outcomes are consistently linked to an increased risk of cardiovascular events. In a systematic review of 12,252 studies, children with ambulatory HTN had an elevated LVH risk (odds ratio, 4.69 [95% CI, 2.69-8.19]), left ventricular mass index, pulse wave velocity, carotid intima-media thickness, and retinopathy and albuminuria compared with normotensive children.²⁶

Subclinical markers related to vascular structures include carotid intima-media thickness (CIMT), arterial stiffness (measured using pulse wave velocity), and endothelial function (assessed through brachial flow mediated dilation).²⁶ Microvascular changes associated with BP have been observed in childhood, including abnormal central retinal arteriolar and venular diameters. Microvascular dysfunction is one proposed mechanism linking higher BP levels to subtle preclinical cognitive function changes in adolescents.

Future Kidney and CV outcomes of pediatric HTN

In a large Israeli military recruits cohort, adolescent HTN (16–19 years old) was associated with an increased long-term kidney failure risk (adjusted hazard ratio 1.98, 95% CI 1.42–2.77), irrespective of BMI status or HTN severity.²⁷

There are recent data showing a strong association between HTN and future CV outcomes. In a recent population-based study in Ontario using health administrative databases with a 13.6 (7.8-19.5) years median (IQR) follow-up, major adverse CV event incidences in children with HTN and controls were 4.6 per 1000 person-years vs. 2.2 per 1000 person-years (hazard ratio, 2.1; 95% CI, 1.9-2.2), respectively. Children with HTN were at higher associated risk of stroke, myocardial infarction, unstable angina, coronary intervention, and congestive heart failure compared with non-hypertensive controls.²⁸ In a large prospective study of the International Childhood Cardiovascular Cohort (i3C) Consortium – published in NEJM in 2022, researchers assessed whether cardiovascular risk factors measured in childhood (ages 3–19) were linked to cardiovascular events in adulthood over an average follow-up period of 35 years. They analyzed factors like BMI, SBP, cholesterol, triglycerides, and youth smoking. Outcomes included both fatal and nonfatal cardiovascular events. This study found that childhood risk factors significantly predicted CV events in adulthood, even when measured decades later. Specifically, smoking increased the risk of fatal CV in adult ages by 60%. The combined-Risk Z score (which incorporated childhood BMI, systolic BP, cholesterol, triglycerides, and smoking status) showed that each unit increase was associated with a 2.71-fold higher risk for fatal CV events in adulthood​. Individual risk measures, such as high systolic BP and elevated cholesterol, found that each unit increase in the z-score raised the hazard for adult CV events by 1.3 to 1.6 times, respectively.²⁹ These findings emphasize CV risk factor management from an early age, as it may significantly reduce the likelihood of adverse CV events later. Another study demonstrated the direct and indirect association between childhood risk factors and adult CVD, with the largest direct effect seen for BMI and LDL-C. The results highlighted that childhood BMI and LDL-C had significant direct effects on later CVD risk, with an incidence rate ratio (RR) of 1.18 for BMI and 1.16 for LDL-C per one standard deviation increase.³⁰ The study emphasized the importance of early-life interventions targeting these risk factors—especially BMI— as childhood influences on CVD risk are not fully mitigated by later risk management.

Non-pharmacological management: Optimal BP thresholds are unknown for pediatric populations, but HTN management aims to minimize future cardiovascular and renal disease risks. Current strategies for pediatric HTN management are primarily at the patient level rather than population-based.²⁵ Non-pharmacological pediatric HTN management involves lifestyle and behavioral changes. Key strategies include:

Dietary Modifications:

Reduced Salt Intake: There is substantial evidence indicating better BP control by lowering dietary sodium in children, showing a dose-dependent effect.^31,32 Two pediatric meta-analyses, encompassing 966 and 58,531 patients, demonstrated significant BP reductions by reducing sodium intake in the diet (approximately 1 mm Hg). This correlation is more pronounced in overweight children and those with low potassium intake.^33,34 The high sodium content in processed foods makes sustainable intake difficult.³⁵ While sodium reduction targets for children remain unclear, the National Academies of Sciences, Engineering, and Medicine have suggested Chronic Disease Risk Reduction Intake limits from adult data extrapolation: < 1200 mg per day for ages 1–3 years, < 1500 mg per day for ages 4–8 years, < 1800 mg per day for ages 9–13 years, and < 2300 mg per day for ages 14–18 years.³⁶ A pragmatic strategy for sodium intake reduction involves a diet with no added salt, cutting high-sodium processed foods, and educating families on how to read and understand food labels.

Healthy Diet: The DASH (Dietary Approaches to Stop HTN) diet was developed in the 1990s as a non-pharmacological method of lowering BP in adults.³⁷ It includes fruits, vegetables, whole grains, lean meat, and low-fat dairy products. There is limited published data showing improves BP in pediatric populations on the DASH diet.^38,39

Nutritional Counselling: Seek guidance from a registered dietitian for personalized dietary advice.

Physical Activity:

Regular Exercise: Minimum 60 minutes of moderate to vigorous physical activity, including walking, biking, swimming, or team sports most days of the week. A recent narrative review inferred the minimal impact of exercise on resting BP in adolescents with normal BP. However, it consistently lowered resting BP in adolescents with HTN.⁴⁰

Limit sedentary lifestyle: Reducing screen time, including time spent on computers, tablets, and television, is important in non-pharmacological pediatric HTN management. A study on US adolescents found ⁓0.2 mmHg SBP increase for an hourly increment of sedentary activity.⁴¹

Weight Management:

Achieve and Maintain a Healthy Weight: Gradual weight loss through diet and exercise is crucial for overweight children. A balanced approach without rapid weight loss is crucial. A systematic review focusing on overweight/obese children found improvements in weight and BP (primarily diastolic BP by 1.69 mmHg) by incorporating lifestyle interventions.⁴²

These non-pharmacological strategies may play a significant role in improving BP control and overall well-being in children with HTN. In reference to our case of primary HTN (10-year-old female), lifestyle modifications are recommended initially and may be effective in reducing BP to normotensive ranges – negating the need for pharmacological management. In contrast, the male, who had a history more suggestive of secondary HTN, will likely require more intensive management of his BP that includes both non-pharmacological and pharmacological management to achieve consistently normotensive BP measurements and reduce sequelae of poorly controlled BP.

Pharmacological management: In the pediatric population, medication becomes a consideration when lifestyle adjustments fail to reach BP targets, there’s a notable rise in BP accompanied by symptoms, a potentially treatable underlying cause is detected, or organ damage is evident. For uncomplicated HTN, both the AAP and HTN Canada guidelines advise starting with ACE inhibitors, ARBs, or long-acting CCBs.^8,43 β-blockers are less preferred due to their side effects and specific cautionary notes regarding their use in individuals with asthma, diabetes, and those engaged in high-performance athletic activities. Refer to Table 8 for common pharmacological agents and their respective dosing guidelines for management of pedaitric hypertension.^42,44-46

The treatment objectives for managing pediatric BP have evolved, driven by emerging trial data. They aim to establish consistent targets for adolescents in alignment with adult guidelines. According to the AAP guidelines, in children < 13 years, the goal is to achieve BP below the 90th percentile based on age and height. For adolescents (aged ≥13 years), aim for a BP <130/80 mmHg, reflecting the recommendations of the adult ACC/AHA guideline.⁸ Alternatively, the European pediatric guidelines adopt adult thresholds, suggesting a target BP < 140/90 mmHg for general HTN in adolescents (aged 16 years and older), and < 130/80 mmHg for those with diabetes mellitus.¹⁶ The SHIP-AHOY (Study of High Blood Pressure in Pediatrics: Adult HTN Onset in Youth) study defined BP categories for adolescents to evaluate their relationship with subclinical target organ injury (TOI) markers. BP was categorized into risk groups based on clinic and ABP readings: low-risk (below the 75^th percentile), mid-risk (75^th to 90^th percentile), and high-risk (above the 90^th percentile). These cutoffs outlined the likelihood of cardiovascular markers such as left ventricular hypertrophy, vascular stiffness, and altered cardiac function based on BP risk level. The study found a strong association between higher ABP levels, particularly SBP, and increased presence of multiple TOI markers, suggesting higher cardiovascular risk among adolescents with elevated BP.⁴⁷

Current literature on pediatric patients with CKD has strong evidence of increased HTN prevalence with higher CKD stages. A prospective observational study by Schaefer et al. showed a 24.4% to 47.4% increase in the prevalence of HTN from CKD stage 3 to 5, and LVH prevalence was higher in the latter.⁴⁸ Similarly, 48% of those being treated for HTN in the CKD study (n=585, children with CKD 1-16 years old) did not have adequate BP control.⁴⁹ These studies affirm the increased HTN prevalence in the CKD population; however; in pediatric patients with CKD, current literature continues to have significant variability in suggested target BP cut-offs [Table 9].^8,16,50-52

Discrepancies in the current literature can confuse clinicians, underscoring the importance of further HTN trials and guideline standardization.

Pediatric HTN is a critical yet under-recognized condition with significant implications for both immediate and long-term health outcomes. Early identification through accurate BP measurement, comprehensive clinical evaluation, and appropriate diagnostic tools like ABPM are essential for timely intervention. Differentiating between primary and secondary HTN guides targeted management strategies, with lifestyle modifications forming the cornerstone. Pharmacological therapy and lifestyle modification with non-pharmacological measures should be considered. Recognizing the potential for target organ damage and increased cardiovascular risk in adulthood underscores the need for proactive, multidisciplinary care. By adopting a systematic approach to the diagnosis and management of pediatric HTN in the outpatient setting, healthcare providers can significantly improve long-term cardiovascular and renal health outcomes for affected children.