Table 1. Demographic and clinical characteristics of CLHLS participants by SBP trajectory classes.
| Characteristics |
Overall (n=10660) |
Class 1 (n=9219) |
Class 2 (n=639) |
Class 3 (n=586) |
Class 4 (n=216) |
P value |
| 80-115 years old a | 6881(64.5) | 5908(64.1) | 500(78.2) b | 341(58.2) b | 132(61.1) | <0.001 |
| Female | 5755(54.0) | 4898(53.1) | 390(61.0) b | 340(58.0) | 127(58.8) | <0.001 |
| Han nationality | 9916(93.0) | 8583(93.1) | 604(94.5) | 534(91.1) | 195(90.3) | 0.045 |
| Education | ||||||
| No schooling | 6008(56.4) | 5149(55.9) | 389(60.9) | 344(58.7) | 126(58.3) | 0.125 |
| Primary school | 3439(32.3) | 2997(32.5) | 193(30.2) | 179(30.5) | 70(32.4) | |
| White-collar | 964(9.0) | 850(9.2) | 59(9.2) | 34(5.8) b | 21(9.7) | 0.046 |
| Average household income (yuan) | ||||||
| < 5000 | 5020(47.1) | 4333(47.0) | 333(52.1) | 265(45.2) | 89(41.2) | 0.013 |
| 5000-19999 | 3955(37.1) | 3400(36.9) | 226(35.4) | 232(39.6) | 97(44.9) | |
| Place of residence | ||||||
| City | 2294(21.5) | 2034(22.1) | 135(21.1) | 83(14.2) b | 42(19.4) | 0.001 |
| Town | 3353(31.5) | 2894(31.4) | 195(30.5) | 203(34.6) | 61(28.2) | |
| Smoking status | ||||||
| Current | 1695(15.9) | 1500(16.3) | 79(12.4) | 86(14.7) | 30(13.9) | 0.198 |
| Past | 2076(19.5) | 1791(19.4) | 131(20.5) | 114(19.5) | 40(18.5) | |
| Alcohol use | ||||||
| Current | 1715(16.1) | 1499(16.3) | 90(14.1) | 100(17.1) | 26(12.0) | 0.325 |
| Past | 1762(16.5) | 1534(16.6) | 108(16.9) | 87(14.8) | 33(15.3) | |
| Regular exercise | ||||||
| Current | 3068(28.8) | 2704(29.3) | 144(22.5) | 162(27.6) | 58(26.9) | <0.001 |
| Past | 1811(17.0) | 1572(17.1) | 129(20.2) | 83(14.2) | 27(12.5) | |
| Sleep quality | ||||||
| Very good or good | 6240(58.5) | 5386(58.4) | 368(57.6) | 371(63.3) | 115(53.2) | 0.002 |
| Fair | 2987(28.0) | 2620(28.4) | 180(28.2) | 131(22.4) b | 56(25.9) | |
| Sleep duration (hours) | 8.00(4.00) | 8.00(4.00) | 8.00(4.00) | 8.00(4.00) | 8.00(3.00) | 0.196 |
| Living alone | 1621(15.2) | 1413(15.3) | 98(15.3) | 82(14.0) | 28(13.0) | 0.654 |
| Heart rate (beat/minute) | 73(12) | 73(12) | 73(12) | 74(13) | 73(13) | 0.417 |
| Body mass index (kg/m2) | 20.05(5.31) | 20.00(5.23) | 20.24(5.34) | 20.57(5.19) ** | 21.38(5.89) ** | <0.001 |
| Diabetes | 1659(15.6) | 1437(15.6) | 114(17.8) | 75(12.8) | 33(15.3) | 0.114 |
| Heart disease | 2272(21.3) | 1935(21.0) | 158(24.7) | 121(20.6) | 58(26.9) | 0.028 |
| Cerebrovascular disease | 1800(16.9) | 1535(16.7) | 126(19.7) | 92(15.7) | 47(21.8) | 0.041 |
| Respiratory disease | 2076(19.5) | 1812(19.7) | 134(21.0) | 83(14.2) b | 47(21.8) | 0.006 |
| Cancer | 900(8.4) | 783(8.5) | 65(10.2) | 36(6.1) | 16(7.4) | 0.078 |
| Dementia | 1049(9.8) | 915(9.9) | 75(11.7) | 40(6.8) | 19(8.8) | 0.030 |
SBP, systolic blood pressure. Data are obtained at the third visit unless noted and expressed as numbers (percentages) or median (interquartile range). Class 1, normal SBP; class 2, stabilized SBP; class 3, elevated SBP; and class 4, persistently high SBP.
aObtained at the first visit.
bThere are statistically significant differences in the pairwise comparison between this class and class 1 trajectory.