Evaluation and Treatment of Renal Causes of Young-Onset Hypertension

Primary Renal Causes in Young Patients

Renal parenchymal disease is the most common cause of secondary hypertension in children and young adults, accounting for 34-79% of cases, followed by renovascular disease at 12-13% 1, 2
The American Academy of Pediatrics recommends that children under 3 years with hypertension be evaluated for congenital anomalies of the kidney and urinary tract (CAKUT), polycystic kidney disease, and obstructive uropathy 1, 3

The American Heart Association suggests suspecting a renal cause when any of the following features are present: stage 2 hypertension (≥140/90 mmHg or ≥95th percentile + 20 mmHg in children), significant diastolic hypertension (>110 mmHg) in patients under age 35, abrupt onset or rapidly worsening hypertension, resistant hypertension (uncontrolled on 3 medications), abdominal or flank bruit on examination, history of urinary tract infections, hematuria, or urinary frequency, and family history of polycystic kidney disease 3, 4, 7, 1

The American College of Radiology recommends renal ultrasonography with Doppler as the mandatory first imaging study for all young hypertensive patients being evaluated for secondary causes, to evaluate for kidney size discrepancy, hydronephrosis, cystic disease, and renal parenchymal scarring 7, 1
The National Institute of Diabetes and Digestive and Kidney Diseases suggests that CT angiography (CTA) or MR angiography (MRA) be used as second-line tests if Doppler ultrasound suggests renovascular disease or clinical suspicion remains high despite normal ultrasound 4, 9, 7

The American Heart Association recommends that renovascular hypertension from fibromuscular dysplasia be treated with angioplasty, with indications for intervention including confirmed hemodynamically significant stenosis (>70-75%), unilateral disease with normal contralateral kidney, and resistant hypertension despite medical therapy 4
The American Academy of Pediatrics suggests that pharmacologic therapy be required for renal parenchymal disease and bilateral disease, with first-line agents including ACE inhibitors, angiotensin receptor blockers (ARBs), long-acting calcium channel blockers, and thiazide diuretics 9, 7, 2

The American Academy of Pediatrics recommends that patients with antihypertensive medication be followed up every 4-6 weeks until blood pressure is controlled, and every 3-6 months once controlled or if managed with lifestyle modifications only 7, 1, 2
The National Institute of Diabetes and Digestive and Kidney Diseases suggests that ADPKD patients have annual blood pressure monitoring, ambulatory blood pressure monitoring (ABPM) yearly, and repeat echocardiography at 6-12 month intervals if left ventricular hypertrophy (LVH) is present or persistent hypertension 6, 9