In old individuals, regulation of blood pressure during postural changes is impaired. Several studies have assessed the clinical impact of orthostatic hypotension (OHypoT) during the aging process. By contrast, the prevalence and prognostic role of the increase in blood pressure in upright position (orthostatic hypertension, OHyperT) in very old adults remain unknown. We investigated the association of OHyperT with cardiovascular (CV) morbi-mortality in a population of very old institutionalized subjects.

A 2-year follow-up longitudinal study was conducted on 972 subjects (mean age [SD] 88[5]) from the PARTAGE study, able to maintain a standing position. OHyperT was defined as an increase in SBP ≥20mmHg during the first and/or 3rd minute of standing. Three groups of subjects were compared: orthostatic normotension (ONT, n=540), OHypoT (n=157) and OHyperT (n=275).

OHyperT prevalence (28%) was higher than OHypoT (16%). Sitting SBP was higher in OHypoT compared to ONT and OHyperT groups (146[23] vs. 136 [21] and 136[20] mmHg, respectively, p<0.001). The OHyperT group was associated with a greater risk of CV morbi-mortality than ONT (HR 1.51[1.09-2.08], p<0.01) and remained unchanged after adjustment for age, sex, sitting SBP and co-morbidities. No difference in CV morbi-mortality was observed between OHyperT and OHypoT groups.

In a very old frail population, the increase in SBP during upright position occurs frequently and is associated with higher CV morbi-mortality independently of sitting BP levels and major co-morbidities. Health professional should take into account not only the decrease but also the increase in BP when standing up.