Influence of blood pressure level and age on within-visit blood pressure variability in children and adolescents
Panagiota Veloudi, Christopher L. Blizzard, Velandai K. Srikanth, Martin G. Schultz, James E. Sharman
Eur J Pediatr. 2018 Feb;177(2):205-210. doi: 10.1007/s00431-017-3049-y.
Panagiota (Penny) Veloudi (Australia)
Summarize your work in one sentence.
This study aimed to determine the magnitude and direction of blood pressure (BP) variability as well as to examine factors (such as age, sex and level of BP) that could affect BP changes within-visit, in children and adolescents.
Summarize your findings in one sentence.
We found that BP is highly variable in children and adolescents (something that could highly affect hypertension assessment); BP variability is greater with higher BP levels but lower with older age and, we also observed that BP increases on repeat measurement in a substantial proportion of the population.
Which were the more important methods you used in this work? If it is not a traditional method you can briefly explain the concept of that methodology.
We have used data from more than 3000 children and adolescents from the Australian Health Survey which was conducted during 2011-2013. These data included two or three BP measurements for each individual and these measures were used to calculate various indices of the magnitude of change, the overall variability and the direction of change (i.e. whether BP was increased or decreased) over repeat measurements. The above variables were the main outcomes of the analyses. We calculated BP level based on absolute BP values as well as BP z-scores, according to guidelines. Finally, we have used regression analyses to examine the relationship of the main outcomes with other predictor variables such as age, sex or BP level.
What did you learn from this paper, what was your take-home message?
The diagnosis of elevated BP in children and adolescents is based on strict probabilistic criteria, for example the difference between the 90th percentile (which defines pre-hypertension) and the 95th percentiles (which defines hypertension) is only 3–4 mmHg. Therefore, BP variability over consecutive measurements could affect BP classification among children and it is important to know how variable is BP in this population. This study showed that BP among children and adolescents is highly variable and that the magnitude of the changes over repeat measures is affected by BP level and age. Additionally, we need to keep in mind that BP does not always drop on consecutive measurements. The take-home message from this study would be that we need to establish evidence-based BP assessment protocols which take into account the above, in order to avoid misdiagnosis of hypertension.