Age Related Normative Changes in Phasic Orthostatic Blood Pressure in a Large Population Study: Findings from the Irish Longitudinal Study on Ageing (TILDA)
Background—In this paper we provide the first normative reference data and prevalence estimates of impaired orthostatic blood pressure (BP) stabilization, initial orthostatic hypotension (IOH) and orthostatic hypotension (OH) based on beat-to-beat blood pressure methods in a population representative sample.
Methods and Results—Participants were recruited from a nationally representative cohort study (>50 years). Beat-to-beat systolic BP (SBP), diastolic BP (DBP) and heart rate (HR) records were analysed among those who underwent an active stand test (N=4475). Normograms were estimated using Generalized Additive Models for Location, Shape and Scale (GAMLSS) with Box-Cox Power Exponential (BCPE) distribution. Prevalence estimates of impaired BP stabilization, IOH and OH are reported. Orthostatic BP responses in adults aged 50-59 years stabilize within 30 seconds of standing with older groups taking 30 seconds or longer. The total prevalence of impaired blood pressure stabilization is 15.6% (95% CI: 14.1-17.1), increasing with age to 41.2% (95% CI: 30.0-52.4) in the over 80's. IOH occurs in 32.9% (95% CI: 31.2-34.6) of the over 50's population with no age gradient evident. The prevalence of OH is 6.9% (95% CI: 5.9-7.8) in the total population increasing to 18.5% (9.0-28.0) in the over 80's.
Conclusions—Significant age related differences exist in the time course of postural BP responses with abnormal responses taking longer than 30 seconds to stabilize. Impaired BP stabilization is more common as we age, affecting over two-fifths of the over 80's population and may play a future role in the management of falls and syncope.
- Received March 4, 2014.
- Revision received August 6, 2014.
- Accepted August 18, 2014.