(a) Classification of blood pressure according to JNC VII* criteria
| Blood pressure | 30–39 yrs. | 40–49 yrs. | 50–59 yrs. | ≥60 yrs. | Total |
|---|---|---|---|---|---|
| no. (%) | no. (%) | no. (%) | no. (%) | no. (%) | |
| n = 367 | n = 306 | n = 215 | n = 351 | n = 1239 | |
| Normotension | 145 (39.5) | 93 (30.4) | 40 (18.6) | 51 (14.5) | 329 (26.6) |
| Prehypertension | 157 (42.8) | 117 (38.2) | 86 (40.0) | 119 (33.9) | 479 (38.7) |
| Stage 1 hypertension | 45 (12.3) | 64 (20.9) | 55 (25.6) | 106 (30.2) | 270 (21.8) |
| Stage 2 hypertension | 20 (5.4) | 32 (10.5) | 34 (15.8) | 75 (21.4) | 161 (13.0) |
Chi-square for trend (χ trend 2) = 113.93, P < .001, df = 1.
*JNC VII classification of blood pressure.