Effect of Aging and Hypertension on Ambulatory Blood Pressure, Arterial Stiffness, and Wave Reflection in Mid-life Adults
Authors: Chang Keng-Yu , Truong Preston , Haun Tabitha , Phan Kelly , Gil Alfredo , Phan Jonathan , Phillips Shane A. 
Published: May 2024

Introduction: Age-associated increases in blood pressure are partly due to increased arterial stiffness and wave reflection. How these vascular changes during aging contribute to daily fluctuations in blood pressure and hypertension remain to be elucidated. Therefore, the purpose of this study is to compare ambulatory blood pressure, arterial stiffness, and wave reflection between young healthy adults, mid-life adults without hypertension, and mid-life adults with hypertension. Methods: Twenty-five young (age: 26 ± 4 yr and body mass index [BMI]: 23.9 ± 2.5 kg/m2) and 31 mid-life adults (age: 57 ± 4 yr and BMI: 25.4 ± 2.6 kg/m2), free of obesity and major clinical diseases and non-smokers, were included. Hypertension was defined by the current use of anti-hypertension medications or offce seated blood pressure (BP) ≥ 130/80 mmHg. Young adults with hypertension were excluded. Twenty-four-hour ambulatory BP monitoring (Oscar 2™, SunTech Medical®) and assessment of aortic arterial stiffness and wave reflection (SphygmoCor XCEL, AtCor Medical) were performed in all participants. Results: Daytime, nighttime, and 24-hr systolic BP was similar between young adults (YA) and mid-life adults without hypertension (MA; n=12; P>0.9 vs. YA), while mid-life adults with hypertension (MAHTN; n=19) had higher offce, 24-hr, daytime, and nighttime systolic and diastolic BP compared to YA and MA (p<0.01 vs. YA and MA). Compared to YA, MA had higher nighttime diastolic BP (P=0.02). Aortic arterial stiffness, measured by carotid-to-femoral pulse wave velocity, was the highest in MAHTN (p<0.001 vs. YA and P=0<0.01 vs. MA), followed by MA (p<0.01 vs. YA) and YA. Aortic wave reflection, measured by augmentation index and reflection magnitude, was higher in MA and MAHTN compared to YA but was similar between MA and MAHTN (p<0.001 for MA vs. YA; p<0.001 for MAHTN vs. YA; and P>0.9 for MA vs. MAHTN). Conclusions: Our findings indicate that 1) mid-life adults with hypertension had higher ambulatory BP and arterial stiffness than mid-life adults without hypertension and young adults; 2) despite normal offce blood pressure, mid-life adults without hypertension had higher nighttime diastolic BP and arterial stiffness than young adults; and 3) regardless of hypertension, mid-life adults had higher wave reflection than young adults. These findings suggest that 1) vascular aging may present prior to the diagnosis of hypertension based on offce BP; 2) arterial stiffness, rather than wave reflection, may contribute to the development of hypertension during aging; and 3) compared to offce BP, ambulatory BP may be a more sensitive marker of age-associated increases in blood pressure. NIAAA K99/R00 AA028537 to CLH. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.