The baseline characteristics of study participants
As shown in Table 1, the involved elderly and hypertensive patients were assigned into CAD group (n=556, aged 69.67±5.89years, 62.6% male) and non-CAD group (n=237, aged 67.88±5.42years, 44.3% male). Male gender was more prevalent among the CAD group. There were more smokers in the CAD group compare to the non-CAD group (p <0.001). CAD patients were older, had a higher prevalence of DM, and also had significantly higher values of LDL-C, Apo B and AIP as compare to those with non-CAD (all p <0.05). Compared with non-CAD group, CAD group had significantly lower levels of HDL-C and Apo A-1 (p all <0.01). There were not different in TC and TG levels between the two groups.
The overall distribution of ABO blood groups was different between those with and without CAD (A 36.0% vs. 29.5%, AB 12.1% vs. 8.0%, B 24.6% vs.33.8%, O27.3% vs. 28.7%, p=0.022). Statistically lower frequency of B was observed in CAD group than that in non-CAD group (33.8% vs. 24.6%, p=0.008).
Table 1. Baseline characteristics of study participants with and without CAD
Variables
|
Hypertensive elderly with CAD (n=556)
|
Hypertensive elderly without CAD (n=237)
|
P value
|
Male, n (%)
|
348 (62.6)
|
105(44.3)
|
<0.001
|
Smoking, n (%)
|
196 (35.3)
|
44(18.6)
|
<0.001
|
Drinking, n (%)
|
67(12.1)
|
22(9.3)
|
0.258
|
Age, y
|
69.67±5.89
|
67.88±5.42
|
<0.001
|
DM, n (%)
|
185 (33.3)
|
53(22.4)
|
0.002
|
TC, mmol/L
|
4.61±1.05
|
4.46±0.99
|
0.053
|
TG, mmol/L
|
1.49(1.08 -2.04)
|
1.40(1.03-2.06)
|
0.280
|
HDL-C, mmol/L
|
1.10±0.26
|
1.17±0.31
|
0.001
|
LDL-C, mmol/L
|
2.91±0.90
|
2.61±0.78
|
<0.001
|
Apo A-1, g/L
|
1.21±0.23
|
1.27±0.24
|
0.001
|
Apo B, g/L
|
0.95±0.26
|
0.89±0.24
|
0.005
|
AIP
|
0.15±0.28
|
0.11±0.29
|
0.047
|
ABO, n (%)
|
|
|
0.022
|
A
|
200 (36.0)
|
70 (29.5)
|
0.080
|
AB
|
67(12.1)
|
19(8.0)
|
0.094
|
B
|
137 (24.6)
|
80(33.8)
|
0.008
|
O
|
152 (27.3)
|
68 (28.7)
|
0.697
|
Lipid profiles between B and non-B blood groups in elderly with hypertension
Comparison of lipid profiles between B and non-B blood groups were presented in Table 2. Data revealed that hypertension elderly with B blood group had significantly lower concentrations of TC, LDL-C, and Apo B than those with non-B blood groups (p= 0.008, 0.010 and 0.007, respectively). Moreover, there were not statistically higher levels of HDL-C, Apo A1 and AIP in B blood group as compared to non-B blood groups (p = 0.778, 0.123 and 0.377, respectively).
Table 2. Lipid profiles between B and non-B blood groups
Lipids
|
B blood group (n=217)
|
Non-B blood group (n=576)
|
P value
|
TC, mmol/L
|
4.41±0.97
|
4.63±1.06
|
0.008
|
TG, mmol/L
|
1.4(1.01-2.04)
|
1.49(1.09-2.07)
|
0.237
|
HDL-C, mmol/L
|
1.11±0.28
|
1.12±0.28
|
0.778
|
LDL-C, mmol/L
|
2.70±0.73
|
2.86±0.92
|
0.010
|
Apo A-1, g/L
|
1.21±0.25
|
1.24±0.23
|
0.123
|
Apo B, g/L
|
0.89±0.25
|
0.94±0.26
|
0.007
|
AIP
|
0.13±0.28
|
0.15±0.28
|
0.377
|
Severity of coronary artery stenosis and B blood group in hypertensive elderly
Table 3 showed that hypertensive elderly patients with B blood group were more likely to have significantly lower number of diseased coronary vessels than those with non-B blood groups (p=0.031). In addition, After Gensini score was assigned into 1st tertile (0-11.5), 2ed tertile (11.5-35.5) and 3rd tertile (>35.5), data revealed that B blood group tended to be associated with significantly lower Gensini score tertile when compared to non-B blood groups. But statistical difference was not obtained (p=0.215).
Table 3. Coronary stenosis severity between B and non-B blood group
Variable
|
B blood group (n=217)
|
Non-B blood group (n=576)
|
P value
|
Number of diseased vessels
|
|
|
0.031
|
0
|
80(36.9)
|
158(27.4)
|
|
1
|
64(29.5)
|
184(31.9)
|
|
≥2
|
73(33.6)
|
234(40.6)
|
|
Gensini score
|
|
|
0.215
|
1st tertile (0-11.5), n (%)
|
82(37.8)
|
181(31.4)
|
|
2ed tertile (11.5-35.5), n (%)
|
65(30.0)
|
199(34.5)
|
|
3rd tertile (>35.5), n (%)
|
70(32.3)
|
196(34.0)
|
|
Logistic regression analysis of B blood group and CAD in elderly with hypertension
Binary multivariate logistic regression was conducted to establish whether B blood group was an independent factor for CAD risk in the patients. According to the univariate regression results shown in Table 4, variables including age (OR 1.057, 95% CI 1.028-1.087) , male gender (OR 2.103, 95% CI 1.545-2.863) , smoking (OR 2.388, 95% CI 1.648-3.460) , DM (OR 1.731, 95% CI 1.217-2.464) , and HDL-C (OR 0.375, 95% CI 0.219-0.642) , LDL-C (OR 1.524, 95% CI 1.262-1.840) , Apo A1 (OR 0.338, 95% CI 0.177-0.645) , Apo B (OR 2.420, 95% CI 1.299-4.510) and B blood group (OR 0.642, 95% CI 0.461-0.894) were included in the model.
After adjustment for such cardiovascular risk factors, multiple logistic regression analysis indicated that B blood group remained an independent protective factor of CAD (OR 0.642, 95% CI 0.450 - 0.916) in elderly patients. Moreover, age, male gender, smoking, DM, LDL-C and AIP were significantly related with increased risk of CAD (OR= 1.068, 95% CI 1.037-1.100; OR= 1.972, 95% CI 1.329-2.928; OR= 1.966, 95% CI 1.244-3.108; OR= 2.085, 95% CI 1.420-3.060, OR= 1.706, 95% CI 1.388-12.096, and OR=1.737, CI 1.006~2.998, respectively). HDL-C was an independently protective factor for CAD (OR= 0.422, 95% CI 0.236-0.753, Table 5).
Table 4. Univariate regression analysis for risk factors and CAD
Variable
|
B
|
S.E
|
Wald
|
Sig.
|
Exp (B)
|
95% CI
|
Male
|
0.744
|
0.157
|
22.308
|
0.000
|
2.103
|
1.545~2.863
|
Age
|
0.055
|
0.014
|
15.413
|
0.000
|
1.057
|
1.028~1.087
|
Smoking
|
0.871
|
0.189
|
21.174
|
0.000
|
2.388
|
1.648~3.460
|
Drinking
|
0.292
|
0.259
|
1.271
|
0.260
|
1.339
|
0.806~2.225
|
DM
|
0.549
|
0.180
|
9.295
|
0.002
|
1.731
|
1.217~2.464
|
TC
|
0.147
|
0.076
|
3.726
|
0.054
|
1.159
|
0.998~1.346
|
TG
|
0.061
|
0.071
|
0.737
|
0.391
|
1.063
|
0.924~1.223
|
HDL-C
|
-0.981
|
0.275
|
12.734
|
0.000
|
0.375
|
0.219~0.642
|
LDL-C
|
0.421
|
0.096
|
19.108
|
0.000
|
1.524
|
1.262~1.840
|
Apo A1
|
-1.086
|
0.330
|
10.812
|
0.001
|
0.338
|
0.177~0.645
|
Apo B
|
0.884
|
0.318
|
7.750
|
0.005
|
2.420
|
1.299~4.510
|
AIP
|
0.552
|
0.279
|
3.927
|
0.048
|
1.737
|
1.006~2.998
|
B blood group
|
-0.444
|
0.169
|
6.893
|
0.009
|
0.642
|
0.461~0.894
|
Table 5. Multiple logistic regression analysis for risk factors with CAD
Variable
|
B
|
S.E
|
Wald
|
Sig.
|
Exp (B)
|
95% CI
|
Age
|
0.065
|
0.015
|
18.893
|
0.000
|
1.068
|
1.037~1.100
|
Male
|
0.679
|
0.202
|
11.352
|
0.001
|
1.972
|
1.329~2.928
|
Smoking
|
0.676
|
0.234
|
8.379
|
0.004
|
1.966
|
1.244~3.108
|
DM
|
0.735
|
0.196
|
14.068
|
0.000
|
2.085
|
1.420~3.060
|
HDL-C
|
-.864
|
0.296
|
8.521
|
0.004
|
0.422
|
0.236~0.753
|
LDL-C
|
0.534
|
0.105
|
25.828
|
0.000
|
1.706
|
1.388~2.096
|
B blood group
|
-.443
|
0.181
|
5.973
|
0.015
|
0.642
|
0.450~0.916
|