Increased prevalence of hypertensive-level blood pressure using the American Academy of Pediatrics 2017 guidelines: a cross-sectional study in a primary school in Thailand.

Background: In 2017, the American Academy of Pediatrics (AAP) launched a new clinical practice guideline for diagnosis of hypertension in children and adolescents. The new cut-off values were 2-3 mmHg lower than those of the previous 2004 guidelines. Aims: This study was conducted to evaluate the effects of the new cut-off values on the prevalence of hypertensive-level blood pressure (BP) in children in a primary school in Bangkok, Thailand. Subjects and methods: BP, weight, height and waist circumference were recorded in 536 school children aged 8-13 years (270 boys, 50.3%) in grades 4-6. For analysis, BP was classified by the two different cut-off values (the 2004 AAP and the 2017 AAP guidelines). Demographic data for the children whose BP was hypertensive according to the 2017 guidelines but not the 2004 guidelines were compared with those of the children with normal BP according to both guidelines. Logistic regression analysis was performed to evaluate the factors associated with hypertensive-level BP. Results: Fifty-eight children (10.8%) had hypertensive-level BP according to the 2017 guidelines but only 37 (6.9%) with the 2004 guidelines. Twenty-one children who would not have had hypertensive-level BP with the 2004 AAP guidelines had greater Z-scores for body mass index and a greater proportion had obesity than the normotensive children. Body mass index was the only independent factor associated with hypertensive-level BP. Conclusions: The prevalence of hypertensive-level BP in children was increased using the 2017 guidelines. Children with hypertensive-level BP using the 2017 AAP guidelines but not the 2004 AAP guidelines had greater BMI Z-scores and a greater proportion were obese than the in the normotensive children. Body mass index was the only independent factor associated with hypertensive-level BP. Abbreviations: AAP: American Academy of Pediatrics; BMI: body mass index; BP: blood pressure; cm: centimeter; DBP: diastolic blood pressure; HT: hypertension; kg: kilograms; m: meter; NHANES: National Health and Nutrition Examination Survey; ROC: receiver operating characteristic curve; SBP: systolic blood pressure; SBPHR: systolic blood pressure-to-height ratio; SD: standard deviation; WC: waist circumference; WHR: waist-to-height ratio.