Table 1.
Baseline Characteristics of 8237 Untreated Participants Cross-Classified by Conventional and 24-Hour Ambulatory Blood Pressure
| Characteristics | Normotension | White-Coat Hypertension | Masked Hypertension | Sustained Hypertension |
|---|---|---|---|---|
| No. of characteristics (%) | 4988 | 881 | 800 | 1568 |
| Women | 2767 (55.5) | 404 (45.9)* | 293 (36.6)* | 522 (33.3) |
| Current smoking | 1544 (31.0) | 168 (19.2)* | 298 (37.3)* | 428 (27.4)* |
| Drinking alcohol | 2304 (47.5) | 381 (46.6) | 458 (60.3)* | 923 (64.6)† |
| Diabetes mellitus | 182 (3.6) | 67 (7.6)* | 57 (7.1) | 149 (9.5) |
| Previous cardiovascular diseases | 237 (4.8) | 126 (14.3)* | 54 (6.8)* | 233 (14.9)* |
| Ethnicity (white) | 4171 (83.6) | 662 (75.3)* | 641 (80.1)† | 1294 (82.6) |
| Mean characteristic (SD) | ||||
| Age, y | 45.7 (15.1) | 59.3 (13.8)* | 52.8 (14.0)* | 60.8 (12.4)* |
| Body mass index, kg/m2 | 24.3 (3.8) | 26.0 (4.1)* | 25.7 (4.0) | 26.9 (4.4)* |
| Total serum cholesterol, mmol/L | 5.44 (1.15) | 5.80 (1.26)* | 5.68 (1.18)† | 5.86 (1.16)* |
| Blood pressure | ||||
| Conventional systolic, mm Hg | 117.0 (11.3) | 148.4 (15.0)* | 126.2 (8.9)* | 156.7 (20.9)* |
| Conventional diastolic, mm Hg | 73.2 (7.9) | 85.6 (9.4)* | 78.7 (7.3)* | 91.7 (10.4)* |
| 24-h systolic, mm Hg | 114.7 (7.7) | 121.4 (6.1)* | 132.7 (7.7)* | 140.8 (12.0)* |
| 24-h diastolic, mm Hg | 69.3 (5.3) | 71.7 (5.2)* | 79.9 (5.8)* | 82.6 (8.3)* |
| Daytime systolic, mm Hg | 121.0 (9.1) | 128.0 (8.3)* | 139.1 (10.0)* | 147.2 (12.9)* |
| Daytime diastolic, mm Hg | 74.5 (6.3) | 76.8 (7.0)* | 84.9 (7.0)* | 87.5 (9.4)* |
| Nighttime systolic, mm Hg | 104.1 (8.8) | 109.7 (8.8)* | 120.9 (10.7)* | 128.8 (15.3)* |
| Nighttime diastolic, mm Hg | 60.2 (6.3) | 62.8 (6.3)* | 70.5 (7.4)* | 73.4 (9.5)* |
Values are number of participants (%) or arithmetic mean (SD). Thresholds for hypertension were ≥140/≥90 and ≥130/≥80 mm Hg on conventional and 24-hour ambulatory measurement, respectively. Normotension and sustained hypertension were consistently normal or elevated blood pressure on both conventional and 24-hour ambulatory measurement. White-coat hypertension had a raised conventional blood pressure and normal 24-hour blood pressure. Masked hypertension had an elevated 24-hour ambulatory blood pressure with normal conventional blood pressure. If for a type of measurement, systolic and diastolic blood pressures were in a different category, participants were classified as hypertensive. Smoking, drinking, diabetes mellitus, history of cardiovascular disease, body mass index, and cholesterol were unavailable in 22, 384, 3, 1, 8, and 611 participants, respectively.
Significance of the difference with the left adjacent column:
P<0.001 and
P<0.05.