Evidence for a Prognostic Role of Orthostatic Hypertension on Survival in a Very Old Institutionalized Population

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 old adults remain unknown. We investigated the association of OHyperT with cardiovascular morbidity and mortality in a population of old institutionalized subjects. A 2-year follow-up longitudinal study was conducted on 972 subjects (mean age [SD] 88 [5]) from the PARTAGE (Predictive Values of Blood Pressure and Arterial Stiffness in Institutionalized Very Aged Population) study, able to maintain a standing position. OHyperT was defined as an increase in systolic blood pressure ≥20 mm Hg during the first and third minute of standing. Three groups of subjects were compared: orthostatic normotension (n=540), OHypoT (n=157), and OHyperT (n=275). OHyperT prevalence (28%) was higher than OHypoT (16%). Sitting systolic blood pressure was higher in OHypoT compared with orthostatic normotension and OHyperT groups (146 [23] versus 136 [21] and 136 [20] mm Hg, respectively, P<0.001). The OHyperT group was associated with a greater risk of cardiovascular morbidity and mortality than orthostatic normotension (hazard ratio 1.51 [1.09-2.08], P<0.01) and remained unchanged after adjustment for age, sex, sitting systolic blood pressure, and comorbidities. No difference in cardiovascular morbidity and mortality was observed between OHyperT and OHypoT groups. In conclusion, in a old frail population, the increase in systolic blood pressure during upright position occurs frequently and is associated with higher cardiovascular morbidity and mortality independently of sitting blood pressure levels and major comorbidities. Health professional should take into account not only the decrease but also the increase in blood pressure when standing up