Table 1.
Baseline characteristics of China Hypertension Survey participants overall and stratified by tertiles of diurnal temperature range.
| Variables | Total (n = 22,702) |
Tertiles of DTR (°C) | p Value | ||
|---|---|---|---|---|---|
| 8.04−8.69 (n = 7808) |
8.69−11.11 (n = 7029) | 11.11−13.43 (n = 7865) | |||
| Age, years | 56.1 ± 13.1 | 57.0 ± 13.3 | 55.9 ± 13.2 | 55.5 ± 12.8 | <0.001 |
| Male, n (%) | 10,505 (46.3) | 3612 (46.3) | 3379 (48.1) | 3514 (44.7) | <0.001 |
| Urban, n (%) | 10,130 (44.6) | 1780 (22.8) | 4654 (66.2) | 3696 (47.0) | <0.001 |
| Han ethnicity, n (%) | 20,315 (89.5) | 7299 (93.5) | 6980 (99.3) | 6036 (76.7) | <0.001 |
| Region, n (%) | <0.001 | ||||
| East | 9263 (40.8) | 5086 (65.1) | 1433 (20.4) | 2744 (34.9) | |
| Central | 9460 (41.7) | 1987 (25.4) | 4909 (69.8) | 2564 (32.6) | |
| West | 3979 (17.5) | 735 (9.4) | 687 (9.8) | 2557 (32.5) | |
| Educational to middle school or higher, n (%) | 11,109 (48.9) | 2638 (33.8) | 4026 (57.3) | 4445 (56.5) | <0.001 |
| Smoking, n (%) | <0.001 | ||||
| Current | 5731 (25.2) | 2179 (27.9) | 1686 (24.0) | 1866 (23.7) | |
| Former | 1216 (5.4) | 392 (5.0) | 359 (5.1) | 465 (5.9) | |
| Never | 15,755 (69.4) | 5237 (67.1) | 4984 (70.9) | 5534 (70.4) | |
| Alcohol consumption, n (%) | 6318 (27.8) | 2096 (26.8) | 2074 (29.5) | 2148 (27.3) | <0.001 |
| BMI (kg/m2), n (%) | <0.001 | ||||
| Underweight | 10,213 (45.0) | 4020 (51.5) | 3062 (43.6) | 3131 (39.8) | |
| Normal | 8533 (37.6) | 2733 (35.0) | 2717 (38.7) | 3083 (39.2) | |
| Overweight | 3956 (17.4) | 1055 (13.5) | 1250 (17.8) | 1651 (21.0) | |
| Hypertension, n (%) | 8957 (39.5) | 2997 (38.4) | 2709 (38.5) | 3251 (41.3) | <0.01 |
| Hypercholesterolemia, n (%) | 7724 (34.0) | 2346 (30.0) | 2514 (35.8) | 2864 (36.4) | <0.001 |
| Diabetes mellitus, n (%) | 2286 (10.1) | 714 (9.1) | 661 (9.4) | 911 (11.6) | <0.001 |
| Family history of CVD, n (%) | 2621 (11.5) | 606 (7.8) | 857 (12.2) | 1158 (14.7) | <0.001 |
| CVD medication history, n (%) | 4929 (21.7) | 1560 (20.0) | 1364 (19.4) | 2005 (25.5) | <0.001 |
| PM2.5 (μg/m3) | 61.7 ± 22.5 | 53.3 ± 11.2 | 76.7 ± 24.2 | 56.7 ± 22.9 | <0.001 |
| NO2 (μg/m3) | 29.3 ± 13.3 | 26.7 ± 7.3 | 36.5 ± 14.9 | 24.8 ± 13.7 | <0.001 |
| NDVI | 0.4 ± 0.1 | 0.6 ± 0.1 | 0.4 ± 0.1 | 0.3 ± 0.1 | <0.001 |
| Relative humidity (%) | 66.1 ± 9.6 | 74.9 ± 2.7 | 66.2 ± 8.1 | 57.4 ± 7.1 | <0.001 |
| Ambient temperature (°C) | 12.8 ± 4.8 | 16.9 ± 1.6 | 14.1 ± 2.9 | 7.6 ± 3.6 | <0.001 |
Numbers are mean ± SD or no. (%). Abbreviations: DTR, diurnal temperature range; BMI, body mass index; CVD, cardiovascular disease; PM2.5, particles with an aerodynamic diameter of ≤2.5 μm; NDVI, normalized difference vegetation index.