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Hypertension is an important risk factor for cardiovascular diseases and metabolic diseases. The number of adults with raised blood pressure is increasing globally. Hypertension, or known as high blood pressure, falls into two categories: Primary hypertension and secondary hypertension. Primary hypertension is very rare in adolescents whereas secondary hypertension develops as a consequence of other diseases. The causes of secondary hypertension vary with age and the etiologic factors of secondary hypertension in adolescents mostly include renal parenchymal disease, CoA (Coarctation of the Aorta), and monogenic disorders.

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AN OVERVIEW OF CASE SUMMARY

The patient was a 17-year-old Chinese teenager who was admitted to Qilu Hospital of Shandong University (China) in May 2020 due to uncontrolled hypertension for 6 months and weakness of limbs for 20 days. Six months prior to admission, blood pressure of the patient was found to have increased to 200/120 mmHg during the physical examination. Since then, his blood pressure fluctuated between 180-200/100-120 mmHg. The patient did not present obvious symptoms like headache, dizziness, palpitation, arrhythmia, or hyperhidrosis. Instead, he bought some antihypertensive drugs (with unknown names, including diuretics) and kept his blood pressure at around 160/100 mmHg.

Twenty days ago, he was admitted to a local hospital due to limb weakness without other symptoms. His blood potassium was 2.51 mmol/L, brain Magnetic Resonance Imaging (MRI) showed cavernous hemangioma, and Magnetic Resonance Angiography (MRA) showed no abnormalities. After discontinuation of diuretic and potassium supplementation, serum potassium was normal. The blood pressure was controlled at about 160/100 mmHg after treatment with spironolactone, amlodipine, and benazepril.

To further clarify the cause, the patient was admitted to the hospital. He had a history of hypospadias. His mother had been not exposed to known teratogens such as tobacco, drugs, radiation, or other toxins during her pregnancy. He had no history of smoking or drinking alcohol, and no family history of hypertension or cardiovascular disease. An extensive workup for full blood count, urine test, urea, liver function, thyroid function, systemic immunity tests, and electrolyte levels was normal. Urinary cortisol: 31.62 (normal: 21 μg/24 h to 110 μg/24 h), urinary Vanillylmandelic Acid (VMA): 6.2 (normal: <13.6 mg/24 h), blood catecholamine’s, and metabolites were normal.

The patient stopped taking the original antihypertensive drugs and changed to terazosin for renin and aldosterone detection 2 weeks later. Further investigations were carried out, and the results showed no abnormalities were observed in bilateral adrenal glands, and also no renal artery stenosis. Long story short, at the follow-up in December 2020, the patient had discontinued his antihypertensive medications and maintained his blood pressure at 120/80 mm Hg.

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RESULTS/FINDINGS

Following the patient’s admission into the hospital, the cause of hypertension was clarified. His characteristics were as follows:

1. He was an adolescent.

2. Blood pressure was severely elevated, and the therapeutic effect of antihypertensive drugs was poor.

3. Typical signs were of upper limb blood pressure was higher than lower limb blood pressure, coarse murmurs audible in the chest, and weakened femoral artery pulsation.

4. He had no history of high-salt diet, obesity, smoking, alcohol consumption, or mental stress.

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Next, the typical causes of secondary hypertension vary according to age. In adolescents whose age is 12 to 18 years, the usual causes are renal parenchymal disease, CoA (Coarctation of the Aorta), and monogenic disorders. According to the patients’ medical history; symptoms, signs, urine tests, blood tests, the adrenal glands CT, and kidney artery CTA, obstructive sleep apnea, renal parenchymal disease, renovascular disease, primary aldosteronism, pheochromocytoma, thyroid disease, drugs, and single-gene disorders were ruled out. The patient’s upper limb blood pressure was higher than the lower limb blood pressure, coarse vascular murmurs could be heard in his chest, and the femoral artery pulsation was weakened. CoA (Coarctation of the Aorta) was highly suspected. The CTA of the thoracic aorta was further improved, which confirmed the secondary hypertension caused by narrowing of the main artery isthmus.

Above all, secondary hypertension is more harmful than primary hypertension. Early identification and early treatment are particularly important. CoA (Coarctation of the Aorta) is an extremely important cause of secondary hypertension in adolescents. Screening the causes of hypertension according to the characteristic symptoms and signs can reduce the patient’s economic burden, shorten the diagnosis and treatment time, and offer the patient more benefits.