Orthostatic Hypertension: A Newcomer Among the Hypertension Phenotypes

Abstract

The prognostic role and the clinical significance of orthostatic hypertension (OHT) remained undefined for long because data were sparse and often inconsistent. In recent years, evidence has been accumulating that OHT is associated with an increased risk of masked and sustained hypertension, hypertension-mediated organ damage, cardiovascular disease, and mortality. Most evidence came from studies in which OHT was defined using systolic blood pressure (BP) whereas the clinical relevance of diastolic OHT is still unclear. Recently, the American Autonomic Society and the Japanese Society of Hypertension defined OHT as an orthostatic systolic BP increase ≥20 mm Hg associated with a systolic BP of at least 140 mm Hg while standing. However, also smaller orthostatic BP increases have shown clinical relevance especially in people ≤45 years of age. A possible limitation of the BP response to standing is poor reproducibility. OHT concordance is better when the between-assessment interval is shorter, when OHT is evaluated using a larger number of BP readings, and if home BP measurement is used. The pathogenetic mechanisms leading to OHT are still controversial and may vary according to age. Excessive neurohumoral activation seems to be the main determinant in younger adults whereas vascular stiffness plays a more important role in older individuals. Conditions associated with higher activity of the sympathetic nervous system and/or baroreflex dysregulation, such as diabetes, essential hypertension, and aging have been found to be often associated with OHT. Measurement of orthostatic BP should be included in routine clinical practice especially in people with high-normal BP.

Exaggerated blood pressure response to standing: a still underinvestigated issue

“…In the longitudinal analysis, for the hyperreactors to standing, the odds ratio was 2.45 [95% confidence interval (95% CI) 1.52–3.97, P < 0.001]. We concur that performing orthostatic BP testing in clinic is logistically simpler than ABPM, as suggested in our previously published flow-chart [7]. Ghazi et al .…”

“…Within the frame of the HARVEST study, we had the opportunity to address this issue because three orthostatic BP assessments were performed over a 3.5-month period [10]. We showed that concordance in the identification of OHT was only fair to moderate and that it differed according to the threshold used to define OHT and the between-measurement interval [7]. The level of concordance was highest (Kappa coefficient, 0.51) when the 10 mmHg cutoff was used to define OHT and when a short time interval was considered (2 weeks).…”

Utility of standing office blood pressure in detecting hypertension in healthy adults

“…Moreover, the group that displayed “hyperreactivity”—the increased SBP to standing, had a higher prevalence of hypertension based on average 24-h ambulatory BP assessment in addition to the near two-fold increase in MACE [hazard ratio of 1.97 (95% CI 1.10–3.52)] based on a 17.2-year follow-up when compared with those with normal response in SBP to standing 30 . Excessive neurohormonal activation and sympathetic overactivity may be responsible for this observation 18 , 30 . Likewise, orthostatic hypotension, defined as a reduction in SBP of ≥ 20 or a reduction in DBP of ≥ 10 mmHg one minute after standing from a seated position, has also been shown to be associated with increased cardiovascular mortality 15 , 31 – 33 .…”