Clinical Demography Characteristics, Routine and Advanced Lipid Parameters
300 patients were enrolled in this study, of which 58 patients were divided into non-CHD Group. (Table 1) In the clinical demography comparisons, age was the only variable with difference between two groups. Routine lipid indexes, TG, HDL-C and advanced lipid indexes, apolipoprotein B (ApoB), TC-p, Lp(a)-p, Lp(a), LDL-size, HDL-p, non-HDL-C-corr were distributed on the skew. apoB, TC-p, LDL-p, LDL-p-corr, non-HDL-C, non-HDL-C-corr, non-HDL-p and non-HDL-p-corr in CHD group were significantly higher than in non-CHD group.
Table 1 Clinical Demography Characteristics, Routine and Advanced Lipids
|
non-CHD Group(n=58)
|
CHD Group(n=242)
|
T / χ2
|
P
|
|
Age, y
|
58.86 ± 8.03
|
65.76 ± 8.46
|
5.628
|
<0.001
|
Smoking, No.
|
7 (12.07%)
|
18 (7.44%)
|
1.708
|
0.252
|
Overweight a, No.
|
19 (32.76%)
|
65 (26.86%)
|
1.327
|
0.369
|
Diabetes, No.
|
19 (32.76%)
|
104 (42.98%)
|
2.022
|
0.155
|
Hypertension, No.
|
34 (58.62%)
|
143 (59.09%)
|
0.981
|
0.948
|
Family history b, No.
|
11 (18.97%)
|
37 (15.29%)
|
1.297
|
0.493
|
TG(mg/dL)*
|
133.92 (106.85, 200.46)
|
148.82 (100.94, 209.08)
|
0.394
|
0.694
|
ApoA1(mg/dL)
|
134.31 ± 15.94
|
130.41 ± 15.74
|
1.693
|
0.092
|
ApoB(mg/dL)*
|
77.91 (58.51,89.86)
|
82.10 (68.75,98.49)
|
2.839
|
0.005
|
TC-p(nmol/L)*
|
1416.58 (1063.81, 1633.81)
|
1492.63 (1250.06, 1790.84)
|
2.839
|
0.005
|
TC(mg/dL)
|
168.16 ± 38.43
|
177.74 ± 38.68
|
1.696
|
0.091
|
Lp(a)-p(nmol/L)*
|
42.80 (16.35, 93.88)
|
36.40 (13.40, 80.00)
|
0.801
|
0.424
|
Lp(a)(mg/dL)*
|
17.83 (6.81, 39.12)
|
14.96 (5.42, 33.12)
|
0.801
|
0.424
|
LDL-p(nmol/L)
|
1042.17 ± 360.58
|
1168.91 ± 366.35
|
2.374
|
0.018
|
LDL-C(mg/dL)
|
81.15 ± 32.77
|
87.30 ± 30.60
|
1.354
|
0.177
|
LDL-size(nm)*
|
20.44 (20.23, 20.68)
|
20.37 (20.17, 20.61)
|
1.634
|
0.103
|
LDL-p-corr(nmol/L)
|
977.50 ± 357.33
|
1108.44 ± 366.46
|
2.456
|
0.015
|
LDL-C-corr(mg/dL)
|
73.10 ± 32.30
|
79.76 ± 30.41
|
1.481
|
0.140
|
HDL-p(nmol/L)*
|
73.35 (45.78, 121.62)
|
78.87 (51.55, 114.60)
|
0.747
|
0.455
|
HDL-C(mg/dL)*
|
45.81 (38.86, 55.28)
|
45.23 (40.46, 50.51)
|
0.877
|
0.381
|
non-HDL-p(nmol/L)
|
1300.29 ± 381.68
|
1463.23 ± 424.55
|
2.675
|
0.008
|
non-HDL-p-corr(nmol/L)
|
1235.62 ± 377.88
|
1402.76 ± 426.11
|
2.740
|
0.007
|
non-HDL-C(mg/dL)
|
120.62 ± 34.74
|
131.50 ± 37.68
|
2.004
|
0.046
|
non-HDL-C-corr(mg/dL)*
|
112.53 (84.79, 136.45)
|
116.96 (96.00, 147.17)
|
2.148
|
0.033
|
a, Overweight was defined as body mass index (BMI) > 28 (BMI = weight (Kg) / height (m)). b, Family history was defined as the age of onset of coronary heart disease less than 55 for men and less than 65 for women, in the immediate family members of patients.
TG, triglyceride; ApoA1, apolipoprotein A1; ApoB, apolipoprotein B; TC-p, total particles of cholesterol; TC, total cholesterol; Lp(a), lipoprotein a; Lp(a)-p, particles of Lp(a); LDL-C, low-density lipoprotein cholesterol; LDL-p, particles of LDL; LDL-size, average diameter of LDL-p; LDL-p-corr and LDL-C-corr, corrected LDL-p and LDL-C; HDL-C, high-density lipoprotein cholesterol; HDL-p, particles of HDL; non-HDL-C, none high-density lipoprotein cholesterol; non-HDL-p, particles of non-HDL; non-HDL-p-corr and non-HDL-C-corr, corrected non-HDL-p and non-HDL-C.
Lp(a) = Lp(a)-p*0.4167; LDL-p-corr = LDL-p – Lp(a)-p; LDL-C-corr = LDL-C – 0.3*Lp(a); non-HDL-p = TC-p – HDL-p; non-HDL-p-corr = non-HDL-p – Lp(a)-p; Non-HDL-C = TC – HDL-C; non-HDL-C-corr = non-HDL-C – 0.3*Lp(a)
TG, ApoB, TC-p, Lp(a)-p, Lp(a), LDL-C-size, HDL-C-p, HDL-C and non-HDL-C-corr were skew distribution and shown as median (25th percentile, 75th percentile). Before the Student’s t-test for the difference between groups, the nonnormal distribution variables were converted into natural logarithm form.
Risk Factors of CHD
The multivariate analysis of risk factors associated with CHD was displayed in Figure 2. Among the 9 variables, Age (hazard ratio (HR) = 2.58, 95% confidence interval (CI): 1.08 ~ 5.86, P = 0.03), ApoB (HR = 1.35, 95% CI: 1.15 ~ 1.59, P < 0.001), LDL-p-corr (HR = 1.05, 95% CI: 1.03 ~ 1.06, P < 0.001) and non-HDL-p-corr (HR = 1.02, 95% CI: 1.01 ~ 1.03, P < 0.001) were risk factors of CHD.
Correlation Analysis of Lipid Indexes and Gensini Score
Figure 3 showed the Spearman correlation analysis of routine, advanced lipid indexes and Gensini score. In general, LDL-C, LDL-p, LDL-p-corr, HDL-C, non-HDL-C, non-HDL-p and non-HDL-p-corr were in linear correlation with Gensini score. The correlation coefficient r ranged in 0.203 of LDL-p-corr to 0.242 of non-HDL-C-p. There was no significant difference in the comparison between routine and advanced lipid items in the correlation analysis with Gensini.
Predictive Ability of Routine and Advanced Lipid Indexes for CHD
In the ROCs, displayed in Figure 4, the most predictive lipid index for CHD was LDL-p-corr, with AUC = 0.759, cutoff of 97.12nmol/L, while the weakest one was HDL-p with AUC = 0.519. The routine lipid items, HDL-C, LDL-C, non-HDL-C and TC were set as the standards in the comparison of the predictive powers. Advanced lipid indexes, LDL-p (P = 0.02) and LDL-p-corr (P = 0.02) were more predictive than the standard (LDL-C), while LDL-size (P = 0.009) and LDL-C-corr (P = 0.03) were less than LDL-C. The predictive capability of non-HDL-p (P = 0.03) and non-HDL-p-corr (P = 0.03) were also stronger than standard (non-HDL-C). Among all lipid indexes, the most sensitive one for CHD was HDL-C (sensitivity, 86.8%), and the most specific was non-HDL-C (specificity, 94.8%).