Objective: To investigate the association of orthostatic hypertension and hypotension with hypertensive target organ damage in middle and old-aged hypertensive patients.
Methods: This cross-section study was conducted in 4711 hypertensive patients aged 40-75 years old in 7 communities of Xinyang County, Henan Province by a multistage cluster sampling method. All patients received a standardized questionnaire, physical and biochemical examinations, echocardiography, ankle-brachial blood pressure index and orthostatic blood pressure measurement. Orthostatic hypertension was defined as an elevation of systolic blood pressure by 20 mm Hg or more while orthostatic hypotension as a drop of blood pressure by 20/10 mm Hg or more. When an upright posture was assumed. Others not belonging to these two conditions were classified into orthostatic normotension.
Results: The prevalence of orthostatic hypertension and hypotension was 16.3% and 23.8% in hypertensive patients. Peripheral artery disease was significantly more frequent in hypertensives with orthostatic hypertension (10.1%) or hypotension (10.7%) than those with orthostatic normotensives (7.4%) (both P<0.05). Patients with orthostatic hypotension had more common left ventricular hypertrophy (53.0% vs 43.2%, P<0.001) and a decreased estimated glomerular filtration rate (38.6% vs 34.4%, P<0.05) than did those with orthostatic normotension. After controlling for age, gender, body mass index and other confounders, orthostatic hypertension was positively associated with peripheral arterial disease (OR 1.39, 95%CI 1.05-1.84) while orthostatic hypotension was significantly associated with peripheral arterial disease (OR 1.45, 95%CI 1.13-1.86) and left ventricular hypertrophy (OR 1.46, 95%CI 1.11-1.84). But no independent association was found between orthostatic hypertension or hypotension and a decreased estimated glomerular filtration rate in hypertensive patients. The adjusted odds ratios (OR) for left ventricular hypertrophy, as predicted by the quintiles of orthostatic systolic blood pressure changes, showed a J-shaped relationship in hypertensive women, and so did peripheral artery disease in untreated hypertensive patients.
Conclusion: Hypertensive patients with orthostatic hypertension or hypotension may have an elevated risk of developing target organ damage.