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A total of 5,346 participants, including 2,567 male and 2,779 female, were recruited and followed up until March 2016. The follow-up rate was 76.52%. The mean ages of the follow-up and the lost for males and for females at baseline were 45.9 ± 14.0 years and 44.2 ± 14.8 years and 44.0 ± 13.5 years and 38.0 ± 14.4 years, respectively. The mean SBP/DBP levels of the follow-up participants were 124.9 ± 16.4 mmHg and 79.1 ± 10.3 mmHg for males and 123.3 ± 19.6 mmHg and 77.2 ± 10.5 mmHg for females at baseline. The mean SBP/DBP levels of the lost participants were 125.0 ± 16.2 mmHg and 78.4 ± 9.2 mmHg for males and 121.6 ± 18.6 mmHg and 76.5 ± 10.0 mmHg for females. As regards the blood pressure, no significant difference was noted between the follow-up and the lost (P > 0.05), except the SBP level of females (P < 0.05). Table 1 lists the other basic characteristics of those followed up and the lost. The difference in age, marital status, and alcohol intake was significant for males between those followed up and the lost. The difference in age, height, mean SBP, marital status, year of education, and occupation was significant for females between those followed up and the lost. Moreover, Supplementary Table S1 (available in www.besjournal.com) shows the demographic characteristics of the study populations stratified by baseline SBP.
Item Male Female Follow-up The lost P value Follow-up The lost P value All 2,567 618 2,779 1,022 Height (cm) 167.3 ± 6.1 167.8 ± 6.9 0.1184 156.3 ± 5.9 157.4 ± 5.6 < 0.0001 Weight (kg) 65.8 ± 9.9 66.6 ± 10.0 0.0752 58.5 ± 9.3 58.8 ± 8.8 0.4087 BMI (kg/m2) 23.5 ± 3.1 23.6 ± 3.2 0.2363 24.0 ± 3.5 23.7 ± 3.3 0.0642 SBP (mmHg) 124.9 ± 16.4 125.0 ± 16.2 0.8993 123.3 ± 19.6 121.6 ± 18.6 0.0168 DBP (mmHg) 79.1 ± 10.3 78.4 ± 9.2 0.0812 77.2 ± 10.5 76.5 ± 10.0 0.0767 Age 18− 336 (13.1) 105 (17.0) 0.0163 424 (15.3) 363 (35.5) < 0.0001 30− 611 (23.8) 164 (26.5) 736 (26.5) 266 (26.0) 40− 626 (24.4) 142 (23.0) 690 (24.8) 167 (16.3) 50− 510 (19.9) 94 (15.2) 526 (18.9) 123 (12.1) 60− 320 (12.4) 70 (11.3) 300 (10.8) 67 (6.6) > 70 164 (6.4) 43 (7.0) 103 (3.7) 36 (3.5) Marital status Married 2,326 (90.7) 513 (83.1) < 0.0001 2,535 (91.2) 858 (83.9) < 0.0001 Unmarried 238 (9.3) 104 (16.9) 244 (8.8) 164 (16.1) Year of Education < 9 1,884 (73.7) 440 (71.3) 0.2805 2,290 (82.6) 713 (69.8) < 0.0001 10− 512 (20.0) 128 (20.8) 383 (13.8) 222 (21.7) 12− 161 (6.3) 49 (7.9) 100 (3.6) 87 (8.5) Occupation Non-manual 552 (21.5) 127 (20.7) 0.1785 274 (9.9) 201 (19.7) < 0.0001 Manual 1,613 (62.9) 373 (60.6) 862 (31.0) 244 (23.9) Others 401 (15.6) 115 (18.7) 1,641 (59.1) 576 (56.4) Smoke Current smoker 1,586 (61.8) 357 (57.8) 0.066 22 (0.8) 13 (1.3) 0.1692 Never smoke 981 (38.2) 261 (42.2) 2,757 (99.2) 1,009 (98.7) Alcohol (times/week) 0 1,622 (65.1) 342 (59.0) 0.0109 2,678 (98.7) 962 (99.1) 0.6633 1− 547 (21.9) 154 (26.5) 20 (0.7) 5 (0.5) 3− 166 (6.7) 52 (9.0) 1 (0.1) 1 (0.1) ≥ 5 158 (6.3) 32 (5.5) 13 (0.5) 3 (0.3) Regular PA Yes 306 (11.9) 67 (10.8) 0.4539 295 (10.6) 93 (9.1) 0.1712 No 2,261 (88.1) 551 (89.2) 2,484 (89.4) 929 (90.9) Note. BMI, body mass index; PA, physical activity. Table 1. Baseline characteristics between the follow-up and the lost population
Total SBP level (mmHg) < 120 120− 140− 160− > 180 P value Number of participants 5,346 2,202 2,221 630 228 65 Age (yrs) 44.9 ± 13.8 39.0 ± 11.9 46.6 ± 13.3 53.8 ± 12.0 57.5 ± 12.0 57.7 ± 11.2 < 0.0001 Height (cm) 161.6 ± 8.1 161.2 ± 7.8 162.6 ± 8.1 160.7 ± 8.8 159.0 ± 8.0 157.2 ± 8.6 < 0.0001 Weight (kg) 62.0 ± 10.2 59.7 ± 9.3 63.5 ± 10.2 64.5 ± 11.3 64.0 ± 10.8 61.8 ± 12.1 < 0.0001 BMI (kg/m2) 23.7 ± 3.3 22.9 ± 3.1 24.0 ± 3.2 24.9 ± 3.9 25.2 ± 3.5 24.9 ± 3.8 < 0.0001 SBP (mmHg) 124.1 ± 18.2 108.7 ± 7.3 126.8 ± 5.8 146.1 ± 6.1 165.7 ± 6.0 190.7 ± 12.5 < 0.0001 DBP (mmHg) 78.1 ± 10.4 71.0 ± 6.8 80.3 ± 7.0 87.7 ± 9.6 92.9 ± 11.5 101.8 ± 14.1 < 0.0001 Marital status < 0.0001 Married 4,861 (91.0) 2,006 (41.3) 2,027 (41.7) 570 (11.7) 203 (4.2) 55 (1.1) Unmarried 482 (9.0) 195 (40.5) 192 (39.8) 60 (12.4) 25 (5.2) 10 (2.1) Year of Education < 0.0001 < 9 4,174 (78.3) 1,631 (39.1) 1,765 (42.3) 520 (12.5) 202 (4.8) 56 (1.3) 10− 895 (16.8) 414 (46.3) 360 (40.2) 91 (10.2) 22 (2.5) 8 (0.9) 12− 261 (4.9) 151 (57.9) 88 (33.7) 17 (6.5) 4 (1.5) 1 (0.4) Occupation < 0.0001 Non-manual 826 (15.5) 401 (48.5) 322 (39.0) 80 (9.7) 19 (2.3) 4 (0.5) Manual 2,475 (46.3) 1,086 (43.9) 1,084 (43.8) 224 (9.1) 65 (2.6) 16 (0.6) Others 2,042 (38.2) 715 (35.0) 813 (39.8) 326 (16.0) 144 (7.1) 44 (2.2) Smoke < 0.0001 Current smoker 1,608 (30.1) 604 (37.6) 770 (47.9) 177 (11.0) 45 (2.8) 12 (0.7) Never smoker 3,738 (69.9) 1,598 (42.8) 1451 (38.8) 453 (12.1) 183 (4.9) 53 (1.4) Alcohol (times/week) < 0.0001 0 4,300 (82.6) 1,796 (41.8) 1,708 (39.7) 532 (12.4) 205 (4.8) 59 (1.4) 1− 567 (10.9) 219 (38.6) 278 (49.0) 55 (9.7) 12 (2.1) 3 (0.5) 3− 167 (3.2) 57 (34.1) 88 (52.7) 16 (9.6) 5 (3.0) 1 (0.6) ≥ 5 171 (3.3) 63 (36.8) 91 (53.2) 11 (6.4) 5 (2.9) 1 (0.6) Regular PA < 0.0001 Yes 601 (11.2) 182 (30.3) 232 (38.6) 119 (19.8) 56 (9.3) 12 (2.0) No 4,745 (88.8) 2,020 (42.6) 1,989 (41.9) 511 (10.8) 172 (3.6) 53 (1.1) Note. BMI, body mass index; PA, physical activity. Table S1. Demographic characteristics of the study populations stratified by baseline SBP
Participants were followed up for 66948.6 person-years. A total of 614 (364 male and 250 female) all-cause death events occurred during the follow-up, among whom were 229 cases < 60 years of age and 385 > 60 years. The crude all-cause mortality rates (95% CI) were 1149.79 (1037.54–1274.19) per 100,000 person-years for males and 708.40 (625.81–801.89) for females. And the crude all-cause mortality rates (95% CI) were 397.62 (349.31–452.60) for persons < 60 years of age and 4115.21 (3724.00–4547.51) for those ≥ 60 years. Table 2 shows the number of deaths and cumulative mortality rates reported for all-cause mortality by gender and age. Significant differences of all-cause mortality were observed between male and female (χ2 = 35.779, P < 0.001) and < 60-year-old and > 60-year-old participants (χ2 = 1223.965, P < 0.001).
Item Death PY Crude mortality rate (95% CI) (/100,000 PY) χ2 P Sex Male 364 31658.0 1149.8 (1037.5–1274.2) 35.779 < 0.001 Female 250 35290.8 708.4 (625.8–801.9) Age < 60 229 57593.2 397.6 (349.3–452.6) 1223.965 < 0.001 ≥ 60 385 9355.4 4115.2 (3724.0–4547.5) Total 614 66948.6 917.1 (847.4–992.6) Note. PY, person-years; CI, confidence interval. Table 2. The number and cumulative mortality rate by sex and age
Figure 1 and Supplementary Table S2 (available in www.besjournal.com) shows the cumulative all-cause mortality rates at different SBP/DBP levels. The gender analysis showed that participants with SBP < 120 mmHg/DBP < 80 mmHg had the lowest cumulative mortality rate, with 596.1/100,000 and 935.2/100,000 for male and 297.3/100,000 and 499.0/100,000 for female, respectively. The cumulative mortality rate rose with the increasing SBP or DBP pressure (χ2trend = 270.537, P < 0.001 for SBP; χ2trend = 57.240, P < 0.001 for DBP). After being stratified by age and gender, the trends that cumulative all-cause mortality rose with blood pressure still existed. However, the cumulative all-cause mortality rate of > 60-year-old participants had an obvious decline at 100–119 mmHg in the DBP group. With the same blood pressure, the cumulative all-cause mortality rate for > 60-year-old participants was higher than those < 60-year-old. As regards gender, no significant difference was recorded between male and female with SBP ≥ 160 mmHg and DBP ≥ 90 mmHg.
SBP < 120 mmHg 120– mmHg 140– mmHg 160– mmHg 180– mmHg χ2 P value Sex Male 596.1
(470.8–754.7)1112.1
(956.4–1293.0)2247.8
(1810.3–4450.9)3147.5
(2225.8–4450.9)5431.1
(3084.5–9563.4)129.177 < 0.001 Female 297.3
(225.3–392.2)810.6
(667.0–985.2)1344.9
(1027.5–1760.5)1980.9
(1400.8–2801.2)3066.5
(1816.1–5177.7)135.924 < 0.001 χ2 14.671 6.433 8.840 3.570 2.262 P < 0.001 0.011 0.03 0.059 0.133 Age < 60 275.8
(219.6–346.3)406.8
(333.0–496.9)679.0
(489.8–941.4)1030.5
(621.2–1709.3)1986.6
(993.5–3972.4)50.494 < 0.001 ≥ 60 2884.7
(2153.8–3863.5)4288.7
(3696.5–4975.7)4328.6
(3554.6–5271.0)4165.1
(3147.9–5510.9)6550.4
(4126.9–10396.8)5.542 0.019 χ2 240.427 539.667 121.818 26.975 9.218 P < 0.001 < 0.001 < 0.001 < 0.001 0.002 Total 419.1
(350.2–501.6)976.3
(866.5–1099.9)1778.9
(1502.8–2105.9)2431.5
(1903.1–3106.6)3837.6
(2612.9–5636.4)270.537 < 0.001 DBP < 80 mmHg 80– mmHg 90– mmHg 100– mmHg 110– mmHg χ2 P value Sex Male 935.2
(795.2–1099.9)1289.7
(1096.5–1516.8)1375.9
(1033.7–1831.2)1622.7
(994.1–2648.7)2783.6
(1448.4–5349.9)16.746 < 0.001 Female 499.0
(411.8–604.8)887.4
(720.1–1093.7)1300.7
(961.3–1760.1)1186.2
(673.7–2888.8)1362.2
(511.2–3629.5)35.266 < 0.001 χ2 24.930 7.846 0.071 0.690 1.517 P < 0.001 0.005 0.790 0.406 0.218 Age < 60 354.5
(295.3–425.6)360.9
(282.5–461.1)492.5
(335.3–723.4)1009.5
(618.5–1647.9)1427.9
(714.1–2855.2)19.367 < 0.001 ≥ 60 3363.1
(2841.1–3981.1)4849.3
(4172.4–5635.9)4610.9
(3602.0–5902.5)2907.5
(1651.2–5119.7)8819.1
(3670.7–21188.4)4.265 0.039 χ2 474.722 541.033 139.365 80525 13.526 P < 0.001 < 0.001 < 0.001 0.004 < 0.001 Total 685.8
(605.9–776.3)1101.8
(969.3–1252.5)1339.3
(1088.1–1646.6)1404.7
(967.8–2030.1)2107.1
(1223.5–3628.9)57.240 < 0.001 Note. CI, confidence interval. Table S2. The cumulative mortality rates of participants at different SBP/DBP level by sex and age
Finally, a Cox proportional hazards model was used to compute HRs and their 95% CIs for total death events, using < 120 mmHg/< 80 mmHg group as a reference, respectively. In the unadjusted Cox proportional hazards analysis, groups with > 120 mmHg SBP and > 80 mmHg DBP were all significantly associated with a greater HR for all-cause mortality compared with the corresponding reference group. The total unadjusted HR (95% CI) was 1.756 (1.644–1.875). After adjusted for the confounding factors, a significant association remains between all-cause mortality and high SBP (≥ 160 mmHg) and high DBP (≥ 100 mmHg), with aHR ranging from 1.405- to 2.179-fold for SBP and 1.550- to 2.854-fold for DBP (P < 0.05 for both). Table 3 shows the unadjusted and adjusted HRs for the association of mortality and SBP/DBP by gender and age. Persons with > 180 mmHg SBP had a significantly higher mortality risk, with HR (95% CI) of 2.506 (1.320–4.758) for males and 1.953 (1.017–3.751) for females. The HRs (95% CI) for persons with > 180 mmHg SBP was 3.714 (1.760–7.836) for those < 60 years of age and 1.947 (1.086–3.491) for those ≥ 60 years. Compared with the DBP reference group, the males in the ≥ 100 mmHg group had a significantly higher mortality with HRs (95% CI) of 2.715 (1.377–5.351). However, none of the DBP groups among females had a significantly increased risk for death with HRs.
Item Total Male
adjusted HR*
(95% CI)Female
adjusted HR*
(95% CI)< 60
adjusted HR*
(95% CI)≥ 60
adjusted HR*
(95% CI)Unadjusted HR Adjusted HR*
(95% CI)SBP 120− 2.302 (1.855–2.858) 1.165 (0.929–1.461) 1.101 (0.819–1.479) 1.120 (0.782–1.602) 1.004 (0.729–1.382) 1.396 (0.997–1.955) 140− 4.247 (3.318–5.436) 1.299 (0.992–1.701) 1.257 (0.879–1.797) 1.248 (0.822–1.895) 1.186 (0.763–1.843) 1.491 (1.028–2.162) 160− 5.790 (4.266–7.858) 1.405 (1.012–1.951) 1.284 (0.811–2.034) 1.338 (0.829–2.160) 1.954 (1.094–3.492) 1.397 (0.913–2.137) 180− 9.374 (6.132–14.33) 2.179 (1.385–3.427) 2.506 (1.320–4.758) 1.953 (1.017–3.751) 3.714 (1.760–7.836) 1.947 (1.086–3.491) Total 1.756 (1.644–1.875) 1.162 (1.067–1.266) 1.193 (1.057–1.346) 1.115 (0.984–1.263) 1.265 (1.092–1.466) 1.117 (1.005–1.240) DBP 80− 1.609 (1.345–1.926) 1.196 (0.996–1.437) 1.096 (0.864–1.390) 1.277 (0.951–1.713) 0.768 (0.559–1.057) 1.556 (1.233–1.965) 90− 1.984 (1.557–2.528) 1.262 (0.980–1.624) 1.120 (0.791–1.586) 1.334 (0.918–1.939) 0.843 (0.537–1.324) 1.620 (1.186–2.214) 100− 2.075 (1.404–3.067) 1.550 (1.036–2.320) 1.467 (0.865–2.489) 1.698 (0.903–3.193) 2.080 (1.214–3.564) 1.151 (0.616–2.148) 110− 3.145 (1.800–5.493) 2.854 (1.630–4.999) 2.715 (1.377–5.351) 2.391 (0.874–6.541) 2.470 (1.194–5.110) 3.526 (1.428–8.705) Total 1.340 (1.250–1.436) 1.164 (1.078–1.257) 1.128 (1.017–1.251) 1.184 (1.052–1.334) 1.116 (0.983–1.267) 1.210 (1.096–1.335) Note. HR, hazard ratio; CI, confidence interval. *Adjusted for education, occupation, marital, smoking, alcohol, physical activity and BMI. Table 3. Hazards ratio for all-cause mortality according to SBP/DBP levels
Association between Baseline SBP/DBP and All-Cause Mortality in Residents of Shanxi, China: A Population-based Cohort Study from 2002 to 2015
doi: 10.3967/bes2021.002
- Received Date: 2020-04-11
- Accepted Date: 2020-11-04
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Key words:
- Blood pressure /
- Mortality /
- Cohort study /
- Hazard ratio /
- Shanxi province
Abstract:
Citation: | WANG Zhuo Qun, ZHAI Yi, LI Man, YANG Xiu Feng, ZHANG Jian, REN Ze Ping, ZHANG Mei, SONG Peng Kun, ZHAO Yan Fang, MI Sheng Quan, ZHANG Lu, YANG Mao Xiang, ZHAO Wen Hua. Association between Baseline SBP/DBP and All-Cause Mortality in Residents of Shanxi, China: A Population-based Cohort Study from 2002 to 2015[J]. Biomedical and Environmental Sciences, 2021, 34(1): 1-8. doi: 10.3967/bes2021.002 |