Table 4.
Relative risk of elevated BP in urban black South African children between childhood and late adolescence
| Mean Age (years) | BP Status | BP status at 18 years | Relative Risk (95 % CI) | |||
|---|---|---|---|---|---|---|
| Normotensive | Elevated BP | Total | Crude | BMI-adjusted | ||
| 5 | Normotensive | 461 (77.3) | 135 (22.7) | 596 (69.4)*** | 1 (ref) | 1 (ref) |
| Elevated BP | 168 (63.9) | 95 (36.1) | 263 (30.6) | 1.60 (1.28–2.00) | 1.60 (1.29–2.00) | |
| Total | 629 (73.2) | 230 (26.8) | 859 (100.0) | |||
| 8 | Normotensive | 454 (77.2) | 134 (22.8) | 588 (66.7)*** | 1 (ref) | 1 (ref) |
| Elevated BP | 184 (62.8) | 109 (37.2) | 293 (33.3) | 1.75 (1.43–2.14) | 1.69 (1.39–2.06) | |
| Total | 638 (72.4) | 243 (27.6) | 881 (100.0) | |||
| 13 | Normotensive | 719 (78.4) | 198 (21.6) | 917 (81.5)*** | I (ref) | 1 (ref) |
| Elevated BP | 91 (43.8) | 117 (56.3) | 208 (18.5) | 2.70 (2.28–3.20) | 2.56 (2.16–3.04) | |
| Total | 810 (72.0) | 315 (28.0) | 1125 (100.0) | |||
| 14 | Normotensive | 770 (80.1) | 191 (19.9) | 961 (75.2)*** | 1 (ref) | 1 (ref) |
| Elevated BP | 147 (46.5) | 169 (53.5) | 316 (24.8) | 2.84 (2.43–3.32) | 2.71 (2.32–3.17) | |
| Total | 917 (71.8) | 360 (28.2) | 1277 (100.0) | |||
| 16 | Normotensive | 830 (80.0) | 207 (20.0) | 1037 (69.4)*** | 1 (ref) | 1 (ref) |
| Elevated BP | 246 (53.7) | 212 (46.3) | 458 (30.6) | 2.34 (2.01–2.72) | 2.28 (2.00–2.65) | |
| Total | 1076 (72.0) | 419 (28.0) | 1495 (100.0) | |||
Chi square test was used to assess the difference in BP status at a given two time points and results presented as proportions: n (%). Some proportions do not add up to 100 % because of rounding off to the nearest percentage and level of significance set at ***P < 0.001