Twenty-four-hour ambulatory central blood pressure in adolescents and young adults: association with peripheral blood pressure and preclinical organ damage.

Abstract

To investigate the relationship of 24-h ambulatory central blood pressure (ABP) with preclinical organ damage in youth. Individuals aged 10-25 years referred for suspected hypertension and healthy volunteers had simultaneous 24-h peripheral and central ABP monitoring (Mobil-O-Graph 24 h PWA). Central BP was calculated using two different calibration methods (c1 using oscillometric systolic/diastolic ABP; c2 using mean arterial/diastolic ABP). Their association with preclinical organ damage [left ventricular mass index (LVMI), carotid intima-media thickness (IMT), 24-h pulse wave velocity (PWV)] was investigated. A total of 136 participants were analyzed (age 17.9 ± 4.7 years, 54% adolescents, 77% males, 34% with elevated ABP). Twenty-four-hour peripheral systolic ABP (pSBP) was higher than c1 systolic ABP (c1SBP) by 14.1 ± 3.7 mmHg, but lower than c2SBP by 6.5 ± 7.6 mmHg (all P < 0.01). c2SBP quartiles provided better stratification of preclinical organ damage than pSBP. Both c1SBP/c2SBP were significantly associated with LVMI (r = 0.35/0.33) and IMT (r = 0.23/0.42; all P < 0.01; primary endpoint). These associations were stronger for c2SBP compared with those of pSBP in adolescents but not in adults. PWV was more closely associated with pSBP than c2SBP (r = 0.94/0.83, P < 0.01). LVMI variation was best determined by c2SBP in adolescents and pSBP in adults; IMT by c2SBP and PWV by pSBP in both subgroups. These findings suggest that in young individuals, the calibration method for 24-h central ABP plays a major role in determining its association with preclinical organ damage. In adolescents, 24-h central ABP appears to be more strongly associated with early cardiac and carotid damage than peripheral BP.