Comprehensive evaluation a must in paediatric hypertension

Children and adolescents with high blood pressure (BP) should be comprehensively assessed to determine the aetiology, discover underlying comorbidities and identify possible target organ damage, says an expert.

The assessment should be even more detailed if the patient is very young, or has stage 2 hypertension—defined as systolic or diastolic BP>99^th percentile plus 5 mmHg—or clinical signs that suggest systemic conditions related to hypertension, said consultant paediatric endocrinologist Associate Professor Muhammad Yazid Jalaludin, of University Malaya Medical Centre.

Primary hypertension accounts for 85 to 90 percent of hypertension in adolescents and is mostly associated with obesity, he said. Meanwhile, in younger children, secondary hypertension is more prevalent, accounting for 90 percent of hypertension in infants and around 85 percent in school-age children. In infants, 40 percent of the secondary hypertension is caused by renal disease and an estimated 35 percent is cardiovascular related. In school-age children, around 70 percent is due to renal disease.

During history taking, try to obtain a complete sleep history, he advised. It is important because being overweight or obese and having high BP is associated with sleep apnoea. Also, ask about risk factors, medication and family history. A comprehensive physical examination should be done—which includes but is not limited to—vital signs, examination of anatomic systems related to hypertension and any external features or syndromes.

Laboratory investigations may be useful as well to help identify the cause of the high BP, discover underlying comorbidities and evaluate target organ damage. Further elaborating, Muhammad Yazid said a complete blood count, kidney function test and renal ultrasound can assist in verifying the aetiology for secondary hypertension. Additionally, retinal examination and echocardiogram can aid in assessing for target organ damage.

A systematic evaluation of the hypertensive paediatric patient is vital to ensure that treatable aetiologies are addressed, especially in those with secondary hypertension. It is also important in patients with primary hypertension to ensure that comorbidities are discovered and effectively managed, he noted.

At the moment, there are 300,000 Malaysian children under the age of 18 who are obese. [National Health and Morbidity Survey Factsheet  2011. Available at www.moh.gov.my/index.php/pages/view/115 Accessed on 26 Jan] With the increasing prevalence of obesity in the country, it is no surprise that paediatric hypertension is becoming more common.