What tests are recommended to evaluate young patients with hypertension?

Evaluation Tests for Young Patients with Hypertension

Young patients with hypertension require a systematic evaluation focused on identifying secondary causes and target organ damage, with specific laboratory and imaging studies determined by age, severity, and clinical presentation.

Initial Assessment

History and Physical Examination

• Obtain detailed history including:

  • Perinatal history (prematurity, low birth weight)
  • Nutritional history (sodium intake, processed foods)
  • Physical activity patterns
  • Psychosocial history (stress, anxiety, depression)
  • Family history of hypertension and cardiovascular disease 1
  • Medication use (including over-the-counter and recreational drugs)
  • Sleep patterns (to assess for sleep disorders)

• Physical examination should include:

  • Accurate height, weight, BMI calculation and percentiles
  • Four-limb blood pressure measurements
  • Assessment for features suggesting secondary causes:
    • Cushingoid features
    • Thyromegaly
    • Abdominal masses
    • Abdominal/epigastric bruits (renovascular disease)
    • Femoral pulses (coarctation)
    • Skin findings (neurofibromatosis, tuberous sclerosis) 1, 2

Laboratory Evaluation

Basic Screening Tests (All Young Hypertensive Patients)

1. Complete blood count
2. Serum electrolytes, BUN, creatinine
3. Fasting glucose
4. Lipid profile
5. Urinalysis
6. Urine albumin/creatinine ratio 1

Additional Tests Based on Clinical Presentation

• For obese patients:

  • Hemoglobin A1c
  • Liver function tests 1
  • Fasting insulin (to assess insulin resistance)

• For suspected secondary causes:

  • Plasma renin activity and aldosterone levels (if hypokalemia present)
  • Thyroid function tests
  • Plasma/urine metanephrines (if pheochromocytoma suspected)
  • Sleep study (if sleep-disordered breathing suspected) 1, 2

Imaging Studies

Renal Ultrasonography

• Recommended for:
  • Children <6 years of age
  • Any patient with abnormal urinalysis or renal function
  • Patients with severe hypertension
  • Patients with family history of renal disease 1

Echocardiography

• Recommended at the time of consideration of pharmacologic treatment to assess for:
  • Left ventricular hypertrophy (LVH)
  • Left ventricular geometry and function
  • LVH defined as LV mass >51 g/m^2.7 for both boys and girls >8 years old 1

Advanced Vascular Imaging (When Indicated)

• For suspected renovascular hypertension:
  • Doppler renal ultrasonography (as initial screening in normal-weight children ≥8 years)
  • CT angiography or MR angiography (if high clinical suspicion) 1

Special Considerations

Ambulatory Blood Pressure Monitoring (ABPM)

• Particularly valuable for:
  • Confirming diagnosis of hypertension
  • Evaluating for white coat or masked hypertension
  • High-risk patients (obesity, CKD, repaired aortic coarctation) 1, 2

Tests to Avoid

• Electrocardiography should not be performed routinely for evaluation of left ventricular hypertrophy due to poor sensitivity despite high specificity 1
• Routine testing for microalbuminuria is not recommended in children with primary hypertension 1
• Vascular imaging such as carotid intima-media thickness or pulse wave velocity measurements are not recommended routinely 1

Age-Specific Considerations

Children <6 Years

• More extensive evaluation for secondary causes is warranted
• Renal ultrasonography should be performed in all cases
• Consider referral to pediatric subspecialist 1, 2

Children ≥6 Years with Risk Factors

• Less extensive evaluation if:
  • Positive family history of hypertension
  • Overweight/obesity
  • No concerning findings on history or physical exam 1

Follow-Up Evaluation

• Repeat echocardiography at 6-12 month intervals if:

  • Persistent hypertension despite treatment
  • Concentric LV hypertrophy present
  • Reduced LV ejection fraction 1

• Consider annual echocardiography for patients with:

  • Stage 2 hypertension
  • Secondary hypertension
  • Chronic stage 1 hypertension with incomplete treatment 1

Common Pitfalls to Avoid

1. Failing to confirm hypertension with repeated measurements before extensive workup
2. Relying on electrocardiography to rule out LVH (high false negative rate)
3. Overlooking secondary causes in young children or those with severe hypertension
4. Not considering masked hypertension in high-risk patients
5. Dismissing hypertension in young patients (lower awareness, delayed diagnosis) 2

Remember that while primary hypertension is becoming more common in children (especially adolescents with obesity), secondary causes remain more prevalent in younger children and those with severe hypertension 2.