Arterial stiffness as underlying mechanism of disagreement between an oscillometric blood pressure monitor and a sphygmomanometer

Oscillometric blood pressure devices tend to overestimate systolic blood pr essure and underestimate diastolic blood pressure compared with sphygmomano meters. Recent studies indicate that discrepancies in performance between t hese devices may differ between healthy and diabetic subjects. Arterial sti ffness in diabetics could be the underlying factor explaining these differe nces. We studied differences between a Dinamap oscillometric blood pressure monitor and a random-zero sphygmomanometer in relation to arterial stiffne ss in 1808 healthy elderly subjects. The study was conducted within the Rot terdam Study, a population-based cohort study of subjects aged 55 years and older. Systolic and diastolic blood pressure differences between a Dinamap and a random-zero sphygmomanometer were related to arterial stiffness, as measured by carotid-femoral pulse wave velocity. Increased arterial stiffne ss was associated with higher systolic and diastolic brood pressure reading s by the Dinamap compared with the random-zero sphygmomanometer, independen t of age, gender, and average mean blood pressure level of both devices. Th e beta -coefficient (95% CI) was 0.25 (0.00 to 0.50) mm Hg/(m/s) for the sy stolic blood pressure difference and 0.35 (0.20 to 0.50) mm Hg/(m/s) for th e diastolic blood pressure difference. The results indicate that a Dinamap oscillometric blood pressure device, in comparison to a random-zero sphygmo manometer, overestimates systolic and diastolic blood pressure readings in subjects with stiff arteries.