24 Hours central blood pressure and pulse wave velocity in normotensive and untreated hypertensive young adults

Abstract

Background: Central hemodynamics and arterial stiffness evaluations are important for cardiovascular risk. The behavior of central blood pressure (CBP), and pulse wave velocity (PWV) during 24 hours is not well known. Objective: To investigate CBP and PWV in relation to brachial BP in 24 hours, awake and sleep periods in normotensive and untreated hypertensive individuals from 18 to 50 years old. Methods: A total of 104 subjects (60 females (57.7%) and 44 males (42.3%)), 48 (46.2%) individuals between 18 and 35 years old and 56 (53.8%) individuals between 36 and 50 years old were included. Exclusion criteria were: use of antihypertensive drugs, body mass index 35 kg/m, eGFR <60 ml/min, diabetes and smoking. All were submitted to clinical and laboratory evaluation; office BP was measured using a oscillometric sphygmomanometer OMRON, model HEM-705CP, and 24h monitoring brachial BP, CBP, Augmentation Index (AIx) and PWV were obtained with the Mobil-O-Graph equipment (DINA MAP cardios ESI GmbH, Stolberg, Germany). Results: The study population showed a mean age of 36.99 8:53 years, BMI 25.80 3.82kg/m, and prevalence of hypertension 32.7%. Office BP means were: systolic BP (SBP) 130.45 17.28mmHg and diastolic BP (DBP) 80.11 10.39mmHg. Awake brachial was lower than office BP (p<0.001, difference between office SBP and awake SBP 1⁄4 11.17 14.21mmHg, and of office DBP and awake DBP 1⁄4 1.76 7.88mmHg). Systolic CBP was lower than brachial SBP in 24h, and awake and sleep periods (p<0.001, differences were 8.49 2.72mmHg, 9.35 3.42mmHg and 5.68 2.96mmHg between brachial SBP and systolic CBP in 24h, awake and sleep periods, respectively). Conversely, diastolic CBP was slightly higher than brachial DBP in 24h, awake and sleep periods (p<0.001, differences were 0.91 1.59mmHg, 1.55 1.78mmHg and 0.82 1.53mmHg between brachial SBP and diastolic CBP in 24h, awake and sleep periods, respectively). There were significant reductions between awake and sleep periods for systolic and diastolic CBP, for AIx and for PWV (p<0.001, differences were 5.62 7.13mmHg, 10.14 7.01mmHg, 3.85 9.07mmHg and 0.19 0.25mmHg for systolic CBP, diastolic CBP, AIx, and PWV, respectively). Conclusion: In normotensive and untreated hypertensive young adults, awake brachial BP was lower than office BP and systolic CBP means were lower than brachial BP, but diastolic CBP means were higher than brachial DBP. Reductions between awake and sleep periods were observed in the CBP, AIx and PWV means, similarly to what is observed with brachial BP, but with lower averages.