How stable is postural hypotension in the general aged population?

Although postural hypotension (PH) is a common clinical symptom in the elderly, nothing is known of its stability in the long run. To investigate this issue we carried out a prospective cohort study in a general aged population as a part of Helsinki (Finland) Aging Study. Random persons of three age cohorts (75-, 80- and 85-years, n = 274) were followed for 5 years. Blood pressure (BP) was measured at supine and standing positions both at entry and after 5 years. Both supine and standing BP levels decreased during 5-year follow-up but the prevalence of PH (decrease in systolic BP > 20 mmHg or that in diastolic BP > 10 mmHg) remained virtually unchanged (28% at entry - 26% after 5 years). There were, however, marked differences in the distributions of individuals in the different categories of PH and only 25.8% of subjects fulfilled the same criteria at 5 years. Only 9% of subjects had significant falls in SBP and DBP both at entry and after 5 years. These persons were characterized by no other clinical features than higher initial supine BP levels. In conclusion, this study shows the instable nature of PH during the 5-year follow-up in the general aged population and challenges the use of blood pressure changes as a sole diagnostic criteria of PH in epidemiological studies.