Ambulatory blood pressure monitoring greatly improves diagnostic accuracy in excess and normal weight children

Abstract

Introduction. Given the significant levels of pediatric excess weight worldwide, we sought to identify the prevalence of abnormally high BP levels (based on auscultatory measurements and ambulatory blood pressure monitoring – ABPM) in a cohort of excess weight children compared to normal weight controls and to analyze the effect of weight loss on BP measurements in the excess weight group. Method. 46 excess weight children and 28 normal weight controls underwent clinical examination, routine blood tests and lipid profile, 12-lead ECG, ABPM and echocardiography. For the excess weight group lifestyle advice was provided and children were subsequently followed up for 12 months. Results. The auscultatory method yielded high rates of arterial hypertension (HTN) (50-58% in the study group and 22-33% in the control group). There was a statistically significant difference in HTN prevalence between the two groups regardless of the standard used to define it. BMI-for-age correlated positively with HTN. The corresponding BP category was generally higher when applying the Unites States guideline. There was a prevalence of HTN of 14.3% in the study group and 4% in the control group according to ABPM results (t (51)= 1.274, p= 0.208, C.I. [-0.06, 0.26]). 48.3% of excess weight children and 56% of controls were non-dippers. There was no significant association between dipping status and ABPM-confirmed hypertension. 64% of excess weight participants exhibited dipping status variability. There was a small, but statistically significant improvement of BMI-for-age within the excess weight group over the follow-up period. There was however no significant drop in HTN levels. HTN prevalence remained much lower when diagnosed by means of ABPM (16.7%) than by manual measurements (42.9%). Discussion. There was a surprisingly high prevalence of arterial hypertension based on manual measurements, mainly driven by high systolic BP values. The numbers decreased significantly after ABPM-based reclassification. Another unexpected find was the high proportion of non-dippers in both groups, which could be partially explained by fragmented, poor quality sleep during monitoring. Conclusions. We found an unexpectedly high prevalence of increased BP levels for age when using manual, in-office measurements only. Ambulatory BP monitoring with pediatric approved devices has proved extremely useful in refining the diagnosis and should thus be employed for confirmation if available. There was an increased prevalence of hypertension in the excess weight group and BMI-for-age correlated positively with BP values. We were unable to demonstrate a reduction in BP levels with improved nutritional status, however we believe this may be achieved with an adequately sized cohort and more stringent lifestyle intervention.

Keywords

• excess weight
• hypertension
• auscultatory
• oscillometric
• abpm
• dipper