Abstract P233: Blood Pressure Variability and Rhythmicity in Adolescents With Spurious Hypertension

Abstract

Objective: Spurious hypertension (sHTN) is characterized by elevated systolic blood pressure (BP) in peripheral arteries but normal central BP. The BP variability and characteristics of BP rhythms in sHTN is unknown. We therefore analyzed BP variability and rhythmicity in adolescents with sHTN in comparison with other forms of hypertension (HTN). Patients and Methods: We studied 265 children (54 girls; 15.1 ±2.5 years) referred with arterial HTN, in whom secondary HTN was excluded. We assessed BP levels - office BP, ABPM, central systolic BP (cSBP), systolic BP average real variability (SBPARV) and mean MAP rhythmicity (amplitudes and acrophases). Anova with TukeyHSD post hoc test was used to compare groups. One tailed t-test was used to compare MAP amplitudes and acrophases with normative values for children with Bonferroni correction for multiple tests. Results: 115 subjects had white coat hypertension (WCH; office BP>95 th perc+ABPM<95 th perc), 25 had ambulatory prehypertension (preHTN; office BP<95 th perc+ABPM<95 th perc+ABPM load >25%), 43 had sHTN (office BP+ABPM >95th perc+cSBP<95 th perc), 82 had true hypertension (tHTN; office BP+ABPM+cSBP >95th perc. There were no significant differences between groups in age, weight and BMI. The median SBPARV was 8.87 in WCH, 8.63 in preHTN, 9.25 in sHTN and 9.28 in tHTN (not significantly different between groups). The prevalence of 24h rhythms ranged from 77 to 88%, not significantly from norms or among groups. The prevalence of 12h rhythms was not significantly different compared to norms and ranged from 50 to 60% (NS among groups). There were also no significant differences in the prevalence of 8h and 6h rhythms. All groups had significantly decreased 24h amplitudes compared to norms, but not significantly different among groups. There were no differences in 12h, 8h and 6 amplitudes between WCH, preHTN, sHTH, tHTN and norms. 24h acrophases were significantly prolonged in sHTN, 12h acrophases were significantly prolonged in preHTN, sHTN and tHTN. Conclusions: Adolescents with spurious hypertension have significantly lower prevalence of 24h rhythms, decreased 24h amplitudes and prolonged 24h and 12h acrophases suggesting increased sympathetic drive similarly to patients with other hypertensive phenotypes.