Table 1. Clinical characteristics and ambulatory blood pressure measurement profiles.
| Variables | Total (n = 103) |
Mild OI (n = 56) |
Severe OI (n = 47) |
p-value |
|---|---|---|---|---|
| Age, yr | 48.6 (17.5) | 50 (15.5) | 47 (19.7) | 0.395 |
| Sex, female (%) | 61 (59.2) | 31 (55.4) | 30 (63.8) | 0.383 |
| BMI, kg/m2 | 23.9 (3.5) | 24.1 (3.3) | 23.6 (3.7) | 0.475 |
| Current smoking (%) | 11 (10.7) | 4 (7.1) | 7 (14.9) | 0.205 |
| Total OIQ score | 11.6 (6.2) | 6.9 (2.7) | 17.2 (4.3) | < 0.001 |
| Valid reading, % | 83.9 (8.4) | 84.6 (8.9) | 83.2 (7.8) | 0.395 |
| Orthostatic response | 0.176 | |||
| Normal (%) | 43 (41.7) | 28 (50) | 15 (31.9) | |
| Hypotension (%) | 33 (32.0) | 15 (26.8) | 18 (38.3) | |
| Tachycardia (%) | 27 (26.2) | 13 (23.2) | 14 (29.8) | |
| Medical history | ||||
| Hypertension (%) | 18 (17.5) | 9 (16.1) | 9 (19.1) | 0.682 |
| Diabetes (%) | 5 (4.9) | 2 (3.6) | 3 (6.4) | 0.658 |
| CAD (%) | 6 (5.8) | 3 (5.4) | 3 (6.4) | 1 |
| Hyperlipidemia (%) | 10 (9.7) | 4 (7.1) | 6 (12.8) | 0.506 |
| Medication (%)* | 30 (29.1) | 14 (25) | 16 (34) | 0.314 |
| Blood tests | ||||
| Total Cholesterol, mg/dL | 177.1 (32.4) | 177.8 (30.9) | 176.2 (34.4) | 0.805 |
| BUN, mg/dL | 13.6 (3.8) | 14 (3.6) | 13.1 (4) | 0.206 |
| Sodium, mmol/L | 140.4 (1.9) | 140.7 (1.7) | 140 (2) | 0.073 |
| BP monitoring | ||||
| SBP, mmHg | ||||
| Total | 114.1 (12.4) | 115.5 (14) | 112.4 (10.1) | 0.198 |
| Awake | 115.6 (12.5) | 116.7 (14) | 114.2 (10.4) | 0.310 |
| Sleep | 111.1 (13.7) | 113 (14.8) | 108.8 (11.9) | 0.122 |
| DBP, mmHg | ||||
| Total | 69.7 (7.6) | 70.5 (7.9) | 68.6 (7.2) | 0.196 |
| Awake | 71 (7.6) | 71.7 (8.1) | 70.1 (6.9) | 0.263 |
| Sleep | 67.2 (8.8) | 68.4 (8.4) | 65.9 (9.1) | 0.156 |
| Mean HR, bpm | ||||
| Total | 65.4 (8.9) | 65 (8.2) | 65.9 (9.7) | 0.585 |
| Awake | 67.2 (10.7) | 66.1 (11.4) | 66.5 (9.8) | 0.277 |
| Sleep | 61.1 (10.1) | 60.9 (9.2) | 61.3 (11.1) | 0.838 |
Data are presented as mean (standard deviation) or number (percentage). Comparisons between two groups were performed by the student’s t-test or chi-square test. Abbreviations: OI, orthostatic intolerance; BMI, body mass index; OIQ, orthostatic intolerance questionnaire; CAD, coronary artery disease; BUN, blood urea nitrogen; SBP, systolic blood pressure; DBP, diastolic blood pressure; HR, heart rate.
*Medication which can cause or aggravate orthostatic intolerance including antihypertensive, vasodilator drugs, and alpha blockers