According to the U.S. Medicaid program, only about 1 in 12 adolescents with hypertension are fully evaluated according to current guidelines. The study was published online in the Archives of Pediatrics and Adolescent Medicine. The study describes the low percentage of adolescents with hypertension who had echocardiography and renal ultrasound as recommended by the 2011 Guidelines for the Diagnosis, Evaluation and Treatment of Hypertension in Children and Adolescents. In contrast, about half of adolescents with hypertension underwent at least 1 ECG, which is not recommended by the guidelines.
A total of 951 adolescent patients aged 12 to 18 years with hypertension diagnosed between 2003 and 2008 were included in the study. Of these, 24% (226) had an echocardiogram, 22% (207) had a renal ultrasound, and 50% (478) had an electrocardiogram, while only 8% (77) had both an echocardiogram and a renal ultrasound. Researcher Dr. Yoon of the University of Michigan concluded that further research is needed to elucidate the reasons physicians make these decisions and the impact of their decisions on treatment outcomes regarding decisions and choices of tests related to target organ damage for the evaluation of adolescent hypertensive patients.
Dr. de Ferranti of Boston Children’s Hospital and Dr. Gillman of the Harvard School of Public Health commented that the study raises additional questions. The reasons for not implementing guideline-recommended screening have not been fully elucidated, and future guideline revisions need to examine not only the evidence for treatment measures in ideal settings, but should also consider what measures can actually be implemented in the real world, given the differences in medical staff, patients, and health insurance.
Hypertension in children and adolescents in China
1. Characteristics and prevalence of hypertension in children
Hypertension in children is mainly primary hypertension, manifested as mild or moderate blood pressure elevation, usually without self-perception, no obvious clinical symptoms, unless regular physical examination, it is not easy to be detected. It is closely associated with obesity, with more than 50% of childhood hypertension being associated with obesity. A 20-year cohort study showed that 43% of children with hypertension developed adult hypertension after 20 years, compared with 9.5% of those with normal blood pressure in children. Left ventricular hypertrophy is the most prominent target organ damage in children with essential hypertension, accounting for 10%-40% of childhood hypertension.
Most children with significantly elevated blood pressure have secondary hypertension, and renal hypertension is the leading cause of secondary hypertension, accounting for about 80% of secondary hypertension. The proportion of primary hypertension gradually increases with age, and adolescents entering adolescence have mostly primary hypertension. According to the survey results of some provinces and cities in the past 10 years, the prevalence of hypertension in children is 2%-4% in preschool children and 4%-9% in school-age children.
2.Diagnosis
Children measure blood pressure in the right upper arm of the seat brachial artery. Choosing the right cuff is very important for the accurate measurement of blood pressure in children. The ideal cuff should have a balloon width equal to at least 40% of the right upper arm circumference, a balloon length that wraps around at least 80% of the upper arm circumference, and a balloon width to length ratio of at least 1:2.
The diastolic pressure readings in children are not uniform at home and abroad as to whether they are taken in the Ⅳth (K4) or Ⅴth (K5) phase of the Koch tone. In adults, K5 is taken as diastolic pressure. Considering the fact that K4 has been adopted as diastolic pressure in pediatric teaching and clinical practice in China, as well as the fact that a significant proportion of children’s Koch sounds do not disappear in the display situation, it is recommended that both K4 and K5 be recorded in actual measurements.
At present, P90, P95 and P99 are universally adopted internationally as the diagnoses of “high normal”, “hypertension” and “severe hypertension”. P90, P95 and P99 were used as criteria for the diagnosis of “high normal”, “hypertension” and “severe hypertension”.
There is no definitive answer to the question of which is a truer reflection of diastolic blood pressure in children, K4 or K5, so this criterion gives both K4 and K5 as diagnostic cut points.
For individuals, hypertension is diagnosed only if the blood pressure level is ≥P95 after 3 or more different timing measurements; subsequently, the degree of hypertension is graded as follows.
① Hypertension grade 1: P95 to P99 +5 mmHg;
The phenomenon of “white coat hypertension” is more common in children and can be identified by ambulatory blood pressure monitoring.
The assessment of hypertension in children includes the following four aspects: the etiology of hypertension, the authenticity of blood pressure levels, target organ damage and extent, other cardiovascular diseases and complications, and the formulation of a reasonable treatment plan based on the assessment.
3. Treatment
Children with primary hypertension or hypertension without combined target organ damage should have their blood pressure lowered to below P95; when combined with renal disease, diabetes or the presence of hypertensive target organ damage, the blood pressure should be lowered to below P90 to reduce damage to target organs and reduce the incidence of long-term cardiovascular disease.
The vast majority of children with hypertension can achieve their blood pressure control goals with nonpharmacologic therapy. Nonpharmacologic therapy involves establishing a healthy lifestyle by.
(1) controlling weight and delaying the rise in BMI ;
(2) increasing aerobic exercise and decreasing static activity time;
(3) adjusting the diet (including salt restriction) and establishing healthy eating habits.
Children with hypertension need to start medication if they have a combination of 1 or more of the following: clinical symptoms of hypertension, secondary hypertension, damage to the target organs of hypertension, diabetes mellitus, and those who have failed after 6 months of non-pharmacological treatment. The principle of pharmacological treatment of hypertension in children is to start with a single agent and small doses. ACEI or ARB and calcium channel blockers (CCB) are less likely to have side effects at standard doses and are usually used as the preferred pediatric antihypertensives; diuretics are usually used as second-line antihypertensives or in combination with other types of drugs to address sodium retention and for secondary hypertension caused by renal disease; other types of drugs, such as alpha-blockers and beta-blockers, are mostly used for severe hypertension and in combination because of side effect limitations.