[Prevalence of symptomatic orthostatic hypotension and orthostatic blood pressure changes]

To analyze the prevalence and orthostatic blood pressure changes in subjects with symptomatic orthostatic hypotension (OH), and to observe the relation between symptoms and orthostatic blood pressure change in this population.

A total of 193 subjects who consulted physicians due to OH related symptoms were selected, and divided into three groups: young (n = 37), middle-aged (n = 66) and elder (n = 90). Height, body weight, waist circumference, hip circumference and resting heart rate were measured. Symptom scores of every subject were obtained. CAVI and ABI were measured. Blood pressure including recumbent position, orthostatic systolic and diastolic blood pressure was measured at the morning and at the afternoon on two separate examination days with at least one week interval. After that, orthostatic changes in systolic blood pressure (OCs) and orthostatic changes in diastolic blood pressure (OCd) were calculated.

OH prevalence was 32.6% in this cohort. The prevalence of three groups was similar [young: 32.4%, middle-aged: 25.8%, and elderly: 37.8%, respectively (P > 0.05)]. Only 9 cases (14.29% of confirmed OH cases) reached the OH diagnostic criteria with equal or more than 2 times orthostatic blood pressure measurements. OH was diagnosed in 63 patients during the 4 times orthostatic blood pressure check, of which 19.5% to 57.14% cases were diagnosed with single orthostatic blood pressure check. Age, weight, body mass index, waist-to-hip ratio, smoking, drinking habit, sex, coronary heart disease, hypertension, Parkinson's disease, stroke history, antihypertensive drug use were similar between OH group and non-OH group. Height, waist circumference, hip circumference, and resting heart rate were significantly lower in OH group than in non-OH group (P < 0.05). The values of the factors in OH group were lower. CAVI was 8.45 ± 0.19 in non-OH group and 8.37 ± 0.27 in OH group (P > 0.05), ABI was significantly lower in OH group than in non-OH group (1.004 ± 0.013 vs. 1.051 ± 0.009, P < 0.01).

The prevalence of OH in people with related symptoms is high. Repeated orthostatic blood pressure measurements can improve OH detection rate.