Exaggerated blood pressure response to standing in young-to-middle-age subjects: prevalence and factors involved.

purposeTo investigate the prevalence of orthostatic hypertension and the association of the blood pressure (BP) level, supine BP decline, and white-coat effect with the orthostatic pressor response.

methodsWe studied 1275 young-to-middle-age individuals with stage-1 hypertension. Orthostatic response was assessed three times over a 3 month period. The white-coat effect was assessed at baseline and after 3 months, and was calculated as the difference between office and average 24 h BP. In 660 participants, urinary epinephrine and norepinephrine were also measured.

resultsAn orthostatic systolic BP increase ≥ 20 mmHg was observed in 0.6-1.2% of the subjects during the three visits. Using the 20 mmHg cut-off, the prevalence of orthostatic hypertension was 0.6%. An orthostatic BP increase of ≥ 5 mmHg was found in 14.4% of participants. At baseline, the orthostatic response to standing showed an independent negative association with the supine BP level (p < 0.001), the supine BP change from the first to third measurement (p < 0.001), and the white-coat effect (p < 0.001). Similar results were obtained in the 1080 participants assessed at the third visit. Urinary epinephrine showed higher values in the top BP response decile (systolic BP increase ≥ 6 mmHg, p = 0.002 versus rest of the group).

conclusionAn orthostatic systolic BP reaction ≥ 20 mmHg is rare in young adults. However, even lower BP increases may be clinically relevant. The BP level, the supine BP decline over repeated measurement, and the white-coat effect can influence the estimate of the BP response to standing and should be considered in clinical and pathogenetic studies.