Sleep-trough morning BP surge associated with arterial stiffness
There is a direct correlation between sleep-trough (ST) morning blood pressure surge (MBPS) and aortic stiffness in untreated hypertension, which is mediated by an elevated average real variability (AVR) of 24-hour systolic BP, a recent study has found.
Furthermore, the adverse effects of MBPS could be due to its relation with arterial stiffness, mediated by short-term SBP variability.
To describe the association between MBPS, short-term BP variability and arterial stiffness, researchers measured carotid-femoral pulse wave velocity (cf-PWV, SphygmoCor) and 24-hour ambulatory BP in 602 consecutive patients with untreated hypertension (mean age 48 years; 61 percent men; office BP, 149/93 mm Hg).
Using self-reported sleep and wake times, researchers defined MBPS as ST, prewaking and rising. They calculated short-term BP variability as weighted 24-hour SBP SD and AVR of 24-hour SBP, which is the average of absolute differences between consecutive SBP readings.
Both ST-MBPS (r=0.16; p<0.001) and rising MBPS (r=0.12; p=0.003) demonstrated a direct association with cf-PWF, while prewaking MBPS did not show such relation (r=0.06; p=0.14).
After adjusting for age, sex, height, office mean arterial pressure, heart rate and renal function, only ST-MBPS showed an independent correlation with cf-PWF (t=1.96; p=0.04). However, this association was lost after further adjustment for weighted 24-hour SBP SD (p=0.13) or ARV (p=0.24).
Finally, ARV was a significant mediator of the association between ST-MBPS and cf-PWF (p=0.003), according to researchers.