Characteristics of study subjects
The characteristics of study subjects were listed in Table 1. The distribution of age and sex was similar for cases and controls (age: P = 0.191, sex: P = 0.896). The mean ages of cases (318 men and 181 women) and controls (323 men and 182 women) were 61.34 ± 11.69 and 60.51 ± 8.11, respectively. Additionally, we collected clinical characteristics of all subjects, including uric acid (UA), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), platelet (PLT), platelet distribution width (PDW), mean platelet volume (MPV), and plateletcrit (PCT). There were significantly different between two groups in the level of UA, TC, LDL, PLT and PCT. In CHD patients, 294 (59%) had hypertension and 100 (20%) had diabetes.
Table 1
Characteristics of study subjects
Variables | Case (N = 499) | Control (N = 505) | P |
Age | 61.34 ± 11.69 | 60.51 ± 8.11 | 0.191 |
> 60 | 270(54%) | 308(61%) | |
≤ 60 | 229(46%) | 197(39%) | |
Sex | | | 0.896 |
Man | 318(64%) | 323(64%) | |
Woman | 181(36%) | 182(36%) | |
UA (umol/L) | 292.67 ± 87.62 | 326.17 ± 80.95 | < 0.001 |
TC (mmol/L) | 4.09 ± 1.15 | 4.78 ± 1.00 | < 0.001 |
TG (mmol/L) | 1.78 ± 1.48 | 1.70 ± 1.18 | 0.418 |
HDL (mmol/L) | 1.13 ± 0.25 | 1.12 ± 0.25 | 0.862 |
LDL (mmol/L) | 1.92 ± 0.82 | 2.64 ± 0.76 | < 0.001 |
PLT (109/L) | 182.43 ± 60.35 | 207.51 ± 56.19 | < 0.001 |
PDW (%) | 14.32 ± 2.79 | 14.10 ± 2.79 | 0.272 |
MPV (FL) | 10.88 ± 1.09 | 10.73 ± 1.06 | 0.051 |
PCT (%) | 0.21 ± 0.07 | 0.23 ± 0.05 | < 0.001 |
Hypertension | | | |
Yes | 294(59%) | | |
No | 205(41%) | | |
Diabetes | | | |
Yes | 100(20%) | | |
No | 399(80%) | | |
Bold values indicate a statistically significant P value (P < 0.05). |
UA, uric acid; TC, total cholesterol; TG, triglyceride; HDL-C, high-density lipoprotein; LDL-C, low-density lipoprotein; PLT, platelet; PDW, platelet distribution width; MPV, mean platelet volume; PCT, plateletcrit. |
Association of NINJ2 polymorphisms and CHD risk
The genotype distribution of NINJ2 polymorphisms was presented in Table 2. All SNPs are in HWE (P > 0.05). In allelic model, no significant association of NINJ2 polymorphisms and CHD risk was observed (P > 0.05). We further performed the association of NINJ2 polymorphisms and CHD risk in multiple models and stratification analysis (Table 3, Table 4, Table 5 and Supplemental table 2). The effects of NINJ2 rs118050317 on CHD risk are dependent on age and sex. For the individuals elderly than 60 years old, rs118050317 was significantly associated with CHD risk in allele (OR = 1.64, 95%CI = 1.13–2.40, P = 0.010), heterozygote (OR = 1.73, 95%CI = 1.11–2.70, P = 0.016), dominant (OR = 1.71, 95%CI = 1.11–2.65, P = 0.015) and additive (OR = 1.63, 95%CI = 1.08–2.46, P = 0.021) models. Similarly, rs118050317 significantly increased CHD risk among women (allele: OR = 1.75, 95%CI = 1.07–2.86, P = 0.026; heterozygote: OR = 1.99, 95%CI = 1.14–3.45, P = 0.015; dominant: OR = 1.92, 95%CI = 1.12–3.28, P = 0.018; additive: OR = 1.74, 95%CI = 1.06–2.86, P = 0.030). In CHD patients, rs118050317 increased the risk of hypertension (allele: OR = 1.66, 95%CI = 1.09–2.53, P = 0.017; heterozygote: OR = 1.72, 95%CI = 1.08–2.76, P = 0.024; dominant: OR = 1.70, 95%CI = 1.08–2.70, P = 0.023; additive: OR = 1.60, 95%CI = 1.04–2.46, P = 0.031), whereas rs7307242 was significantly associated with decreased hypertension risk (homozygote: OR = 0.35, 95%CI = 0.13–0.99, P = 0.049; recessive: OR = 0.35, 95%CI = 0.13–0.99, P = 0.047). In addition, rs75750647 and rs10849390 had strong association with diabetes risk in CHD patients (P < 0.05).
Table 2
Genotype distribution of NINJ2 polymorphisms and Hardy-Weinberg equilibrium test for the healthy controls
SNP | Chromosome: BP | Allele | Group | AA | AB | BB | OR(95%CI) | P | PHWE |
rs118050317 | 12: 634980 | C/G | CHD | 6 | 102 | 391 | 1.16(0.87–1.54) | 0.310 | 1.000 |
| | | control | 6 | 102 | 391 | | | |
rs75750647 | 12: 638831 | A/G | CHD | 44 | 224 | 231 | 0.93(0.77–1.12) | 0.440 | 0.763 |
| | | control | 56 | 220 | 229 | | | |
rs7307242 | 12: 641529 | A/T | CHD | 17 | 110 | 371 | 1.05(0.81–1.34) | 0.729 | 0.261 |
| | | control | 13 | 114 | 376 | | | |
rs10849390 | 12: 646086 | A/G | CHD | 66 | 232 | 197 | 1.18(0.98–1.42) | 0.084 | 0.919 |
| | | control | 53 | 220 | 220 | | | |
rs11610368 | 12: 662624 | A/G | CHD | 11 | 104 | 383 | 1.43(0.86–1.48) | 0.384 | 0.659 |
| | | control | 5 | 105 | 395 | | | |
CHD, coronary heart disease; A means minor allele; B means major allele; OR, odd ratio; CI, confidence interval; HWE, Hardy-Weinberg equilibrium. |
Table 3
Association of NINJ2 polymorphisms and CHD risk
SNP | Homozygote | Heterozygote | Dominant model | Recessive model | Additive model |
| OR(95%CI) | P | OR(95%CI) | P | OR(95%CI) | P | OR(95%CI) | P | OR(95%CI) | P |
rs118050317 | 1.22(0.37–4.03) | 0.748 | 1.17(0.85–1.60) | 0.341 | 1.17(0.86–1.59) | 0.323 | 1.18(0.36–3.9) | 0.785 | 1.15(0.87–1.53) | 0.329 |
rs75750647 | 0.76(0.49–1.18) | 0.228 | 1.01(0.78–1.31) | 0.937 | 0.96(0.75–1.23) | 0.750 | 0.76(0.50–1.15) | 0.198 | 0.92(0.76–1.12) | 0.406 |
rs7307242 | 1.34(0.64–2.80) | 0.437 | 0.98(0.73–1.32) | 0.900 | 1.02(0.76–1.35) | 0.906 | 1.35(0.65–2.81) | 0.428 | 1.05(0.82–1.33) | 0.715 |
rs10849390 | 1.38(0.92–2.08) | 0.121 | 1.18(0.90–1.54) | 0.221 | 1.22(0.95–1.57) | 0.123 | 1.27(0.86–1.86) | 0.228 | 1.18(0.98–1.42) | 0.086 |
rs11610368 | 2.27(0.78–6.61) | 0.132 | 1.03(0.76–1.40) | 0.852 | 1.09(0.81–1.46) | 0.585 | 2.26(0.78–6.56) | 0.134 | 1.13(0.87–1.48) | 0.364 |
CHD, coronary heart disease; OR, odd ratio; CI, confidence interval. |
Table 4
Association of NINJ2 rs118050317 and CHD risk after age and sex stratification
Model | Age | Sex |
> 60 | ≤ 60 | Man | Woman |
OR(95%CI) | P | OR(95%CI) | P | OR(95%CI) | P | OR(95%CI) | P |
Allele | 1.64(1.13–2.40) | 0.010 | 0.73(0.47–1.12) | 0.146 | 0.94(0.66–1.33) | 0.713 | 1.75(1.07–2.86) | 0.026 |
Homozygote | 1.45(0.23–9.02) | 0.691 | 0.72(0.12–4.40) | 0.725 | 1.33(0.29–6.02) | 0.709 | 1.09(0.15–7.97) | 0.935 |
Heterozygote | 1.73(1.11–2.70) | 0.016 | 0.75(0.46–1.24) | 0.265 | 0.89(0.6–1.31) | 0.542 | 1.99(1.14–3.45) | 0.015 |
Dominant | 1.71(1.11–2.65) | 0.015 | 0.75(0.46–1.22) | 0.250 | 0.90(0.62–1.33) | 0.607 | 1.92(1.12–3.28) | 0.018 |
Recessive | 1.31(0.21–8.12) | 0.773 | 0.77(0.13–4.65) | 0.772 | 1.37(0.30–6.16) | 0.685 | 0.95(0.13–6.92) | 0.957 |
Additive | 1.63(1.08–2.46) | 0.021 | 0.77(0.49–1.21) | 0.261 | 0.93(0.66–1.33) | 0.704 | 1.74(1.06–2.86) | 0.030 |
CHD, coronary heart disease; OR, odd ratio; CI, confidence interval. |
Table 5
Association of NINJ2 polymorphisms and CHD risk after disease stratification
SNP | Model | Hypertension vs Non-hypertension | Diabetes vs Non-diabetes |
| | OR(95%CI) | P | OR(95%CI) | P |
rs118050317 | Allele | 1.66(1.09–2.53) | 0.017 | 0.83(0.50–1.39) | 0.479 |
| Homozygote | 1.44(0.25–8.12) | 0.682 | - | - |
| Heterozygote | 1.72(1.08–2.76) | 0.024 | 0.92(0.53–1.60) | 0.780 |
| Dominant | 1.70(1.08–2.70) | 0.023 | 0.86(0.50–1.48) | 0.581 |
| Recessive | 1.29(0.23–7.27) | 0.776 | - | - |
| Additive | 1.60(1.04–2.46) | 0.031 | 0.80(0.48–1.34) | 0.404 |
rs75750647 | Allele | 1.13(0.86–1.48) | 0.391 | 1.50(1.09–2.07) | 0.014 |
| Homozygote | 0.98(0.51–1.90) | 0.961 | 2.20(1.05–4.63) | 0.037 |
| Heterozygote | 1.36(0.93–1.98) | 0.116 | 1.63(1.01–2.62) | 0.044 |
| Dominant | 1.28(0.89–1.84) | 0.175 | 1.72(1.09–2.71) | 0.019 |
| Recessive | 0.85(0.45–1.60) | 0.615 | 1.71(0.85–3.41) | 0.130 |
| Additive | 1.13(0.85–1.50) | 0.404 | 1.53(1.09–2.14) | 0.013 |
rs7307242 | Allele | 0.79(0.56–1.13) | 0.199 | 0.86(0.54–1.36) | 0.512 |
| Homozygote | 0.35(0.13–0.99) | 0.049 | 0.83(0.23–2.99) | 0.781 |
| Heterozygote | 1.01(0.65–1.56) | 0.974 | 0.85(0.49–1.46) | 0.551 |
| Dominant | 0.88(0.58–1.32) | 0.530 | 0.85(0.50–1.42) | 0.524 |
| Recessive | 0.35(0.13–0.99) | 0.047 | 0.87(0.24–3.08) | 0.823 |
| Additive | 0.81(0.57–1.14) | 0.218 | 0.87(0.56–1.35) | 0.543 |
rs10849390 | Allele | 1.07(0.82–1.39) | 0.616 | 0.70(0.50–0.98) | 0.035 |
| Homozygote | 1.10(0.62–1.95) | 0.739 | 0.44(0.20–0.99) | 0.047 |
| Heterozygote | 1.18(0.80–1.74) | 0.410 | 0.75(0.47–1.20) | 0.232 |
| Dominant | 1.16(0.80–1.68) | 0.428 | 0.68(0.43–1.06) | 0.088 |
| Recessive | 1.01(0.59–1.72) | 0.973 | 0.51(0.23–1.11) | 0.089 |
| Additive | 1.08(0.83–1.42) | 0.557 | 0.70(0.50–0.98) | 0.037 |
rs11610368 | Allele | 0.89(0.61–1.30) | 0.544 | 0.82(0.50–1.34) | 0.432 |
| Homozygote | 1.93(0.50–7.45) | 0.341 | 1.43(0.37–5.53) | 0.607 |
| Heterozygote | 0.80(0.51–1.24) | 0.313 | 0.69(0.38–1.25) | 0.226 |
| Dominant | 0.86(0.56–1.32) | 0.492 | 0.76(0.43–1.31) | 0.321 |
| Recessive | 2.03(0.53–7.82) | 0.303 | 1.54(0.40–5.93) | 0.534 |
| Additive | 0.95(0.65–1.38) | 0.781 | 0.85(0.52–1.37) | 0.500 |
CHD, coronary heart disease; OR, odd ratio; CI, confidence interval. |
Haplotype analysis
We also conducted haplotype analysis of NINJ2 polymorphisms and CHD risk (Supplemental table 3). We did not find significant association between haplotype of NINJ2 polymorphisms and susceptibility to CHD (P > 0.05). As it shown in Fig. 1, there are two blocks in NINJ2 (block 1: rs118050317 and rs75750647; block 2: rs7307242, rs10849390 and rs11610368).
Association of genotypes of NINJ2 polymorphisms and clinical indicators of CHD patients
In Supplemental table 4, we showed the association of different genotypes of NINJ2 polymorphisms (rs118050317, rs75750647, rs7307242, rs10849390 and rs11610368) and clinical indicators (UA, TC, TG, HDL, LDL, PLT, PDW, MPV and PCT) of CHD patients. All patients with different genotypes had significantly difference in rs118050317, rs11610368 and PLT level (Prs118050317 = 0.041, Prs11610368 = 0.040). There were no strong relationships between other polymorphisms and clinical indicators in CHD patients.