Baseline demographic and clinical characteristics
A total of 166 688 studied hypertension patients (80251 male, 86437 female; mean age: 63.16 ± 11.22 years old) were included in this final data analysis. Among these hypertension patients, the blood pressure value at the time of registry: systolic blood pressure was 154.49 ± 13.83 mmHg; diastolic blood pressure was 92.57 ± 8.74 mmHg. Overall, 11143 hypertension patients had developed cerebrovascular diseases (CVD) from hypertension before the deadline, and cumulative incidence of CVD was 6.68%. The mean age of hypertension patients complicated by cerebrovascular disease was 73.44 ± 10.39 years old and the average observation duration or followed up time was 5.83 ± 3.95 years.
Figure 2 showed that the types and incidence of 11143 cerebrovascular disease in hypertension patients, 7932 cases were ischemic cerebrovascular (the proportion was 71.18% and cumulative incidence was 4.76%); 663 cases were hemorrhagic cerebrovascular (the proportion was 5.95% and cumulative incidence was 0.40%); 2548 cases were unclassified stroke (the proportion was 22.87% and cumulative incidence was 1.53%). In the ischemic cerebrovascular, there were 7609 (cumulative incidence was 4.56%) cerebral infarction (CIS, I63), 323 (cumulative incidence was 0.19%) transient ischemic attack (TIA, G65). In the hemorrhagic cerebrovascular, there were 133 (cumulative incidence was 0.08%) subarachnoid hemorrhage (SAH, I60), 491 (cumulative incidence was 0.29%) intracerebral hemorrhage (ICH, I61), 39 (cumulative incidence was 0.02%) non-traumatic intracranial hemorrhage (NTICH, I62).
Hp Characteristics And Cvd
In this followed up observational cohort of hypertension patients, the cerebrovascular disease (CVD) cumulative incidence of male was 7.02% (5636/80251), and female was 6.37% (5507/86437). Male was higher than female (x2 = 35.385, p < 0.001). Age distribution: the CVD cumulative incidence in HP patients under 30 years old were 0% (0/40), 30 ~ 39 years old 2.01% (21/1047), 40 ~ 49 years old 2.39% (135/5641), 50 ~ 59 years old 4.20% (911/21671), 60 ~ 69 years old 4.44% (2492/56186), over 70 years old 9.24% (7584/82103). There was no CVD case in the hypertension patients group under 30 years old and cumulative incidence of CVD was the highest in the age group over 70 years old. Cumulative incidence of CVD increased with age (x2 = 82.174, p < 0.001). See Table 1.
Table 1
Cumulative incidence of cerebrovascular diseases in hypertensive patients with different sex, age and blood pressure type (n, %)
|
|
N
|
Unclassified stroke(I64)
n (%)
|
Ischemic cerebrovascular
|
Hemorrhagic cerebrovascular
|
Total
n (%)
|
x2
p
|
|
|
CIS
(I63)
|
TIA
(G45)
|
Total
n (%)
|
SAH
(I60)
|
ICH
(I61)
|
NTICH
(I62)
|
Total
n (%)
|
Sex
|
male
|
80251
|
1373 (1.71%)
|
3754
|
158
|
3912 (4.87%)
|
66
|
268
|
17
|
351 (0.44%)
|
5636 (7.02%)
|
x2 = 35.385
|
Female
|
86437
|
1175 (1.36%)
|
3855
|
165
|
4020 (4.65%)
|
67
|
223
|
22
|
312 (0.36%)
|
5507 (6.37%)
|
p < 0.001
|
Age
(y)
|
< 30
|
40
|
0 (0.00%)
|
0
|
0
|
0 (0.00%)
|
0
|
0
|
0
|
0 (0.00%)
|
0 (0.00%)
|
x2 = 82.174
p < 0.001
|
30~
|
1047
|
2 (0.19%)
|
15
|
1
|
16 (1.53%)
|
0
|
3
|
0
|
3 (0.29%)
|
21 (2.01%)
|
40~
|
5641
|
13 (0.23%)
|
110
|
3
|
113 (2.00%)
|
1
|
8
|
0
|
9 (0.16%)
|
135 (2.39%)
|
50~
|
21671
|
66 (0.30%)
|
755
|
40
|
795 (3.67%)
|
6
|
42
|
2
|
50 (0.23%)
|
911 (4.20%)
|
60~
|
56186
|
141 (0.25%)
|
2104
|
91
|
2195 (3.91%)
|
28
|
114
|
14
|
156 (0.28%)
|
2492 (4.44%)
|
≥ 70
|
82103
|
2326 (2.83%)
|
4625
|
188
|
4813 (5.86%)
|
98
|
324
|
23
|
445 (0.54%)
|
7584 (9.24%)
|
BP
|
High SBP
|
31747
|
428 (1.35%)
|
1474
|
51
|
1525 (4.80%)
|
31
|
100
|
7
|
138 (0.43%)
|
2091 (6.59%)
|
x2 = 23.883
p < 0.001
|
High DBP
|
4553
|
64 (1.41%)
|
859
|
44
|
903 (19.83%)
|
14
|
66
|
3
|
83 (1.82%)
|
1050 (23.06%)
|
HBP
|
130388
|
2057 (1.58%)
|
5275
|
228
|
5503 (4.22%)
|
88
|
325
|
29
|
442 (0.34%)
|
8002 (6.14%)
|
Total
|
166688
|
2548
(1.53%)
|
7609
(4.56%)
|
323
(0.19%)
|
7932
(4.76%)
|
133
(0.08%)
|
491
(0.29%)
|
39
(0.02%)
|
663
(0.40%)
|
11143
(6.68%)
|
|
(Note: TIA = transient ischemic attack; CIS = cerebral ischemic stroke /Cerebral infarction; TIA: transient ischemic attack; SAH = subarachnoid hemorrhage; ICH: intracerebral hemorrhage; NTICH: non-traumatic intracranial hemorrhage; n(%) = number (cumulative incidence %); High SBP = only high systolic blood pressure; High DBP = only high diastolic blood pressure; HBP = high systolic and diastolic blood pressure) |
Among these cerebrovascular disease in hypertension patients, the proportion of ischemic cerebrovascular, hemorrhagic cerebrovascular and unclassified stroke were respectively 71.17%, 5.95% and 22.88% of the total number of CVD. Cerebral infarction (CIS) and transient ischemic attack (TIA) were respectively 68.28% and 2.90% of the total number of CVD in ischemic CVD; subarachnoid hemorrhage SAH), intracerebral hemorrhage (ICH) and non-traumatic intracranial hemorrhage (NTICH) were respectively 1.19%, 4.41% and 0.35% of the total number of CVD. The observation results of this hypertension cohort showed that ischemic CVD was the most important type of CVD in HP patients.
Figure 3 showed cumulative incidence of CVD was different in different levels of registered blood pressure of HP patients (x2 = 113.895, p < 0.001). When 140mmHg ≦ SBP < 160 mmHg or 90mmHg ≦ DBP < 100 mmHg (Called grad I), cumulative incidence of CVD was 6.34% (6074/89744); 160mmHg ≦ SBP < 180 mmHg or 100mmHg ≦ SBP < 110 mmHg (Called grad II), cumulative incidence of CVD was 6.69% (3521/ 49137); 180mmHg ≦ SBP or 110mmHg ≦ DBP (Called grad Ⅲ), cumulative incidence of CVD was 8.50% (1548/16664). The higher the registered blood pressure was, the higher the cumulative incidence of CVD was. Table 1 showed that cumulative incidence of CVD was different in different types of hypertension, cumulative incidence of CVD was 6.59% (2091/31747) in high SBP (only high systolic blood pressure) patients; 23.06% (1050/4553) in high DBP (only high diastolic blood pressure); 6.14% (8002/130388) in HBP (systolic and diastolic blood pressure were high). The results showed that cumulative incidence of CVD in high DBP was significantly higher than that in other patients (x2 = 23.883, p < 0.001).
Hp Duration And Cvd
With the extension of the duration of hypertension, cumulative incidence of CVD will continue to increasing, cumulative incidence of CVD was 3.76% within one year and 11.34% after 10 years. Cumulative incidence of different types of cerebrovascular diseases was also different (x2 = 173.546, p < 0.001). See Fig. 4. Generally speaking, the peak of cumulative incidence of CVD in hypertension patients was 9–10 years after the registered and followed-up. After that, cumulative incidence will drop slightly, and the clam will remain at a high level. Cumulative incidence of ischemic CVD would continue to increasing with the extension of the duration of hypertension. Cumulative incidence of hemorrhage CVD had been maintained at a low level, and the fluctuation range was not very large. In fact, unclassified stroke also included cerebral infarction and hemorrhage cerebrovascular disease; therefore, the changed trend of its incidence rate was basically consistent with that of the overall cerebrovascular disease.
Seasons Distribution Of Cvd
Among 11143 CVD in HP patients, season distribution was different. From January to December, the proportion of CVD in HP patients were respectively 7.53%、7.29%、8.55%、8.96%、9.71%、9.10%、9.63%、8.13%、8.01%、8.15%、7.19% and7.76%, The difference of the proportion of different types of CVD in different months was obvious (x2 = 149.439, p < 0.001). The proportion of patients from January to March accounted for 23.51% of the total number of patients; that from April to June accounted for 27.03%; from July to September accounted for 26.13%; and from October to December accounted for 23.32%. The difference of the proportion of different types of CVD in different seasons was obvious (x2 = 60.656, p < 0.001). See Fig. 5. Comparatively speaking, the number of patients of CVD from April to June was the largest in the four seasons; the next was that from July to September; the number of patients from October to December was the minimum.