Use of Single Blood Pressure Cutoffs to Determine High Cimt in Children and Adolescents: An International Collaboration Study

Background: Pediatric blood pressure (BP) levels are typically assigned to categories when they exceed sex-, age-, and height-specific 90th (elevated) and 95th percentile (high) cutoffs. Given the number of stratum, there are hundreds of cutoffs for defining elevated and high BP that make it cumbersome to use in clinical practice. In 2017 the American Academy of Pediatrics (AAP) recommended simplified cutoffs of ≥120/80 mmHg and ≥130/80 mmHg be used to diagnose elevated BP and high BP, respectively, in clinical practice for adolescents aged 13-17 years. Accordingly, we suggest cutoffs of ≥110/70 mmHg and ≥120/80 mmHg be used for elevated BP and high BP among children aged 6-12 years. The aim of this study was to evaluate the utility of the simplified cutoffs for pediatric BP in determining high carotid intima-media thickness (cIMT) in children and adolescents. Methods: Data were from 6 population-based cross-sectional studies in Brazil, China, Greece, Italy, Spain and the UK. A total of 4280 children and adolescents aged 6-17 years were included. High cIMT was defined as cIMT ≥sex-, age- and cohort-specific 90th percentile cutoffs. Logistic regression model, receiver operating characteristic (ROC) curve and net reclassification improvement (NRI) methods were used to compare the performance of the simplified definition with three established complex definitions (i.e. 2017 AAP guideline, 2004 Fourth Report, and 2016 international BP references) in determining high cIMT (≥sex-, age- and cohort-specific 90th percentile of cIMT) in children and adolescents. Results: Compared with those who had normal BP, participants with high BP defined using either of the three complex definitions or simplified definition had similar odds of high cIMT, with odds ratios and 95% confidence intervals of 1.46 (1.15-1.86), 1.47 (1.10-1.96), 1.42 (1.12-1.80), and 1.65 (1.25-2.17), respectively, after adjustment for sex, age, race/ethnicity, body mass index, high density lipoprotein-cholesterol, triglyceride, and fasting blood glucose. The similar utility of all four high BP definitions in determining high cIMT were further confirmed by area under the ROC curve and NRI methods (all p for difference >0.05). Interpretation: The simplified BP definition performed similarly with three complex definitions in determining high cIMT in children and adolescents. The simplified definition offers a similarly accurate but more convenient means to identify pediatric high BP in clinical practice. Funding: Dr Bo Xi was supported by the National Natural Science Foundation of China (81673195). Dr. Costan G. Magnussen was supported by a National Heart Foundation of Australia Future Leader Fellowship (100849). Declaration of Interest: None Ethical Approval: Each study was approved by the corresponding institutional review board, and written informed consent was obtained from all study participants and their parents or guardians.