Persistence and determinants of blood pressure phenotypes according to office and ambulatory blood pressure measurements in youth.

Ambulatory BP monitoring is increasingly used in children and adolescents, and the persistence of discrepant phenotypes, such as white coat or masked hypertension, is a relevant issue. The objective of this study was to assess the persistence of BP phenotypes over time and the factors related to their persistence. The study included 582 children and adolescents (9.4  ±  2.8 years of age) of both sexes (51% females) referred for routine health maintenance. Anthropometric parameters and office and 24-h ABPM measurements were obtained twice (interval 19.5  ±  6.9 months). BP classification and phenotypes were qualified using the 2016 ESH Guidelines. The correlation coefficient and kappa statistics were used to assess the persistence of phenotypes, and the related factors were evaluated using logistic regression. Based on both systolic and diastolic BP measurements, 91.6%, 16%, 17.2% and 13.7% of the subjects with true normotension, sustained HTN, white coat HTN and masked HTN, respectively, remained in the same category (overall agreement 74.2%, kappa 0.20). The multivariate model predicted the lack of persistence and correctly classified 90.3% of the subjects, with the pathological baseline BP phenotype (mainly masked HTN) being the independent variable that contributed most to the model. Excluding the phenotypes, the rest of the model explained 14% of the lack of persistence, and a high office SBP and high waist circumference were related to the lack of persistence. Furthermore, subjects who experienced an increase in their BMI z score and change in their BMI category were at risk of a lack of persistence. In conclusion, children, especially those with BP phenotypes different from true normotension, should be re-evaluated because a large percentage are likely to become normotensive.