Blood Pressure Reclassification in Adolescents Based on Repeat Clinic Blood Pressure Measurements

Abstract

The common assumption is that blood pressure (BP) will decrease on subsequent readings. The objective of this study is to examine the prevalence and direction of BP classification change with repeat measurements and compare common clinical characteristics of groups of patients who do and do not have a change in BP classification. A nationally representative subsample of 1725 adolescents aged 13 to 18 years from the National Health and Nutrition Survey were analyzed. Three BP measurements were obtained. Patients were classified based on the first and the average of 3 BP measurements as having normal BP, hypertension, and/or prehypertension. Of the 1725 adolescents, 1569 (90.9%) maintained BP classification, 107 (6.2%) had a reduction in their classification, and 49 (2.9%) had an increase in their classification. Comparing the two groups that changed BP classification to the group without change, C‐reactive protein and body mass index (BMI) z score were significantly higher in the groups that had a change in BP classification (P=.02 and <.001, respectively). After adjusting for other variables, higher BMI value was significantly associated with change in BP classification. With repeat measurements, the majority (~91%) did not have a change in classification. Obesity was a significant predictor of the 9% that had a change in classification. Repeat BP measurements in obese adolescents may lead to more accurate classification of BP status.

Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents

“…82 BP generally decreases with repeated measurements during a single visit, 83 although the variability may not be large enough to affect BP classification. 84 BP measurements can also vary across visits 64,85 ; one study in adolescents found that only 56% of the sample had the same HTN stage on 3 different occasions. 8 Therefore, it is important to obtain multiple measurements over time before diagnosing HTN.…”

Prevalence of and Trends in Dyslipidemia and Blood Pressure Among US Children and Adolescents, 1999-2012

“…10,32 Furthermore, some of the studies included in the Fourth Report 21 were based on only a single BP measurement and the number of BP measurements can affect results. [33][34][35] Regardless of the source of the cut points used to define adverse lipid and BP levels in children and adolescents, these definitions are not based on cardiovascular events but rather on statistical definitions and/or expert opinion. This differs from adults in whom the associations between cardio-vascular events and both dyslipidemia and hypertension are more clearly delineated.…”

Screening for Hypertension in Children and Adolescents: Methodology and Current Practice Recommendations

“…The AHA and the NHLBI recommend the patient’s BP be measured and recorded at least twice at each occasion, and the average of SBP and DBP be recorded (6, 7). However, Becton and colleagues (24) conducted an evaluation of NHANES data and found that in greater than 90% of adolescents aged 13–18 years, the BP classification remained the same in repeat sequential measurements.…”