Risk of Arterial Stiffness Associated With Masked Hypertension and Nocturnal Dipping Status Measured by Ambulatory Blood Pressure Monitoring in Population With Prehypertension

Objective: To determine the risk of arterial stiffness associated with masked hypertension and the circadian rhythm of blood pressure (BP) in individuals with prehypertension (office BP of 120-139/80-90 mmHg). Design and method: The Ambulatory 24-hour Blood Pressure Monitoring (ABPM) and Evaluation of Cardiovascular Risk in Prehypertensive Population (AMEC-Pre; ChiCTR2300073286) is a community-based prospective cohort study designed to provide evidence-based guidance for better management of BP in China. Between March 2023 and May 2024, the study enrolled 9,693 prehypertensive participants aged 35–80 years who had not taken any antihypertensive medications in the past 3 months. A total of 8,883 participants were included in the final analysis. Masked hypertension was defined as an office BP of <140/90 mmHg, and ABPM at least 130/80 mmHg over 24 hours or at least 135/85 mmHg for daytime average or at least 120/70 mmHg for nighttime average. Nocturnal dipping status was defined based on the BP reduction while asleep versus awake: extreme dipper (at least 20%); dipper (10% to <20%); non-dipper (0% to <10%); and riser (any increase). Arterial stiffness was defined as a brachial-ankle pulse wave velocity at least 1800 cm/s. Results: Of all, 48.8% had masked hypertension and 43.6% had a non-dipper pattern at self-reported bed time. The risk of arterial stiffness was elevated in individuals with isolated nocturnal hypertension (odds ratio OR 1.65, 95% confidence interval CI 1.38–1.97), isolated daytime hypertension (OR 1.95, 95%CI 1.40–2.73), and day-night hypertension (OR 2.86, 95%CI 2.41–3.40). The risk was also higher in prehypertensive individuals aged 35-59 years than in those aged 60-80 years (P for interaction=0.04). Elevated risk of arterial stiffness was observed in non-dipper pattern (OR 1.19, 95%CI 1.02–1.39) and riser pattern (OR 1.26, 95%CI 1.02–1.55) compared with the dipper pattern. This relationship remained consistent when using the fixed clock-time intervals (daytime, 7 AM to 10 PM; nighttime,10 PM to 7 AM). Conclusions: The risk of arterial stiffness was significantly associated with masked hypertension and nocturnal dipping status in prehypertensive individuals, especially those aged 35-59 years. Community-based ABPM is important to identify masked hypertension, thereby guiding early preventive strategies for arterial stiffness.