Author Response: Systolic Blood Pressure Postural Changes Variability is Associated With Greater Dementia Risk.

Abstract

The authors thank Dr. Pinar Soysal for this comment on our article.1 We agree that the original standard diagnostic criteria of orthostatic hypotension (OHYPO), commonly based on supine-to-stand BP, are a reduction in systolic blood pressure (SBP) of at least 20 mm Hg or DBP of at least 10 mm Hg.2 The studies Dr. Pinar Soysal mentions assessed orthostatic BP response from a supine-to-standing position, which is not the case of the Health ABC Study. Indeed, given that the prevalence of OHYPO is higher in older adults and many of whom have comorbidities that may affect mobility, a sit-to-stand testing often offers a safer method to transfer a patient into an upright position without triggering an acute fall or syncopal event. Because of the reduced acute change in gravitational stress, the sit-to-stand test makes conventional BP cutoffs to diagnose OHYPO challenging to reach. An insignificant number of participants in the Health ABC Study had baseline OHYPO using that definition. Very recently, optimal diagnostic thresholds for the diagnosis of OHYPO with a sit-to-stand test have been proposed by Shaw et al.3 A sit-to-stand SBP drop of ≥15 mm Hg had optimal test characteristics (sensitivity = 80%; specificity = 89%), as did a DBP drop of ≥7 mm Hg (sensitivity and specificity both = 87%).3 We, therefore, used this threshold—consistent with previous large studies—including the Hypertension in the Very Elderly Trial (HYVET).4,5