Fractional Blood Pressure Across Childhood and Adolescence: A Descriptive Analysis Derived from Pediatric Blood Pressure Reference Tables

Background/Objectives: Fractional blood pressure (FBP), calculated as pulse pressure divided by systolic blood pressure × 100, is mathematically equivalent to the pulse pressure index expressed as a percentage. This study characterized age-related patterns in calculated FBP and pulse pressure (PP) across childhood and adolescence. Methods: FBP and PP were calculated using values derived from published pediatric blood pressure reference tables for children aged 1–17 years. Calculations were performed for the reference-table normotensive scenario and reference-table stage 2 hypertension threshold scenario and analyzed by age and sex. Results: During early childhood, FBP declined from 52% to 41% in boys and from 50% to 40% in girls; corresponding calculated FBP values in the reference-table stage 2 hypertension threshold scenario declined from 42% to 33% and from 37% to 32%, respectively. Thereafter, FBP remained relatively stable, ranging from 38% to 42% in boys and from 39% to 41% in girls. Corresponding calculated FBP values in the reference-table stage 2 hypertension threshold scenario remained lower, ranging from 30% to 35% in boys and from 31% to 33% in girls. PP declined modestly during early childhood and increased during adolescence, particularly in boys. Conclusions: FBP declined during early childhood and remained relatively stable thereafter despite increases in absolute blood pressure, whereas PP increased during adolescence. Calculated FBP was lower in the reference-table stage 2 hypertension threshold scenario than in the reference-table normotensive scenario across all ages studied. These descriptive findings require validation using paired, individual-level pediatric blood pressure data.