P2.B040: Multiple Office Blood Pressure Measurement for the Diagnosis of Hypertension in Children

Background: Blood pressure (BP) measurement (M) in children may be challenging. Current international guidelines suggest measuring BP three times. However, in a previous study, we reported that both systolic (S) and diastolic (D) BP values of the first three readings are unreliable.
At our Centre, multiple Office BP Measurement (mOBPM) has been introduced as standard practice for hypertension diagnosis in children since 2010. mOBPM consists of 10 serial BP readings taken at 3-minute intervals using a validated automated oscillometric device. After discarding outlier readings ( < 5th and >95th centile of the recorded values), the coefficient of variation (CV) and the remaining SBP and DBP mean values are calculated by a software.
This contribution is aimed at testing mOBPM in a cohort of children to confirm our previous observations, and to bolster its use as an effective and practical tool to assess BP in children.

Methods: School children underwent mOBPM at baseline and after 12 months. After excluding M series with a CV>15%, the mean SBP and DBP values obtained by mOBPM were compared with the 1st, 2nd, 3rd and 4th M (t test for paired data). The number of children with BP>90th centile within the aforementioned M was also determined.

Results: One hundred and seventy-five children (94 females, 53.4%) with a mean age of 8.6±0.3 and a mean BMI of 17.5±2.9 (BMI >20, n = 34; 19.4%) were enrolled. Thirteen mOBPM were excluded for a CV>15% in either SBP or DBP. As represented in Figure 1, the remaining 328 mOBPM showed that the mean of the first three SBP and DBP values were higher (p < 0.001) than those obtained with mOBPM. The same held true for the mean of the 2nd and 3rd M, whereas the 4th M was the first one not significantly different from mOBPM. The number of children with BP>90th centile by each reading and by mOBPM is also provided in Figure 1.

Conclusion: These findings confirm that relying solely on the first three BP measurements overestimates the number of hypertensive subjects, prompting unnecessary and burdensome diagnostic and therapeutic pathways. The 4th reading is more reliable but mOBPM provides a better evaluation of BP particularly when initial readings show higher than normal BP values.