Abstract
Yin et al. (Bioscience Reports (2019) 39, BSR20180923) recently published a meta-analysis about the association between the K469E (rs5498) polymorphism and risk of coronary heart disease (CHD). Authors included 14 studies based on their inclusion criteria. They indicated that only studies which their genotyping data were in Hardy–Weinberg equilibrium (HWE) were included in their meta-analysis. They also tested HWE for these studies and found all the control groups in HWE. As their main finding, they concluded that ‘K469E polymorphism is associated with CHD risk and the K allele is a more significant risk factor for developing CHD amongst Chinese and Caucasians populations’. However, there seems to be presenting some mistakes in HWE test which strongly affects included studies and the final conclusion. Here we aim to comment on the issue.
Dear Editor,
Unfortunately, based on our analysis, contrary to meta-analysis by Yin et al. [1], studies they included in their meta-analysis were not in Hardy–Weinberg equilibrium (HWE), and many included articles (seven articles) show deviation from HWE, even after adjustment. It seems that authors made some mistake in calculating HWE. In Table 1 we showed P-values for HWE test and ineligible studies, based on ‘HardyWeinberg’ package in R programming language (https://cran.rproject.org/web/packages/HardyWeinberg/HardyWeinberg.pdf). Our results were double checked with STATA (genhwi form of genhw, https://www.stata.com/users/mcleves/genhw/genhw.hlp), and also manually. In manual method, P-value of HWE test was calculated based on four following steps. (i) We calculated allele frequencies in control group: K = [(2 × KK) + KE]/(2 × total), so E should be E = 1 − K. (ii) We calculated expected genotypes based on allele frequencies: KK = K2 × total, KE = (2 × K × E) × total, and EE = EE2 × total. (iii) We carried out chi-square test between observed and expected genotypes (χ2 = Σ(Ob − Ex)2/Ex). (iv) Finally, results were interpreted based on chi-square routine distribution table (steps (i–iii) are shown in Table 2 and step (iv) in Table 3). Also regarding the study by Sarecka-Hujar et al. [2], the genotyping data were not correctly included in Table 1 of their meta-analysis, GG(EE) and AA(KK) genotypes and allele frequencies were displaced in both case and control groups. Correct data are shown in Table 1. Also, they [2] indicate that ‘the distribution of ICAM1 genotypes was not compatible with HWE’ which clearly violates inclusion criteria (iv) in Yin et al. [1] meta-analysis.
Studies . | Case KK . | KE . | EE . | Control KK . | KE . | EE . | P-value . | Adjusted P-value . | Design . |
---|---|---|---|---|---|---|---|---|---|
Shang, Q. (2005) | 48 | 50 | 24 | 29 | 33 | 35 | 0.002 | 0.005 | Exclude |
Li, Y.J. (2010) | 47 | 39 | 7 | 52 | 36 | 13 | 0.103 | 0.180 | Include |
Lu, F.H. (2006) | 61 | 69 | 30 | 45 | 65 | 59 | 0.003 | 0.008 | Exclude |
Zhang, S.R. (2006) | 111 | 52 | 10 | 69 | 59 | 13 | 0.940 | 0.973 | Include |
Rao, D. (2005) | 84 | 41 | 20 | 59 | 19 | 66 | <0.001 | <0.001 | Exclude |
Wei, Y.S. (2006) | 124 | 84 | 17 | 101 | 103 | 26 | 0.973 | 0.973 | Include |
Zhou, Y.L. (2006) | 38 | 45 | 20 | 102 | 62 | 33 | <0.001 | <0.001 | Exclude |
Wang, M. (2005) | 96 | 61 | 8 | 91 | 90 | 18 | 0.524 | 0.734 | Include |
Jiang, H. (2002) | 202 | 226 | 100 | 60 | 66 | 87 | <0.001 | <0.001 | Exclude |
Milutinović, A. (2006) | 47 | 72 | 33 | 65 | 109 | 41 | 0.695 | 0.811 | Include |
Sarecka-Hujar, B. (2009) | 61 | 118 | 12 | 73 | 122 | 8 | <0.001 | <0.001 | Exclude |
Mohamed, A. (2010) | 20 | 37 | 43 | 2 | 11 | 37 | 0.332 | 0.516 | Include |
Luo, J.Y. (2014) | 339 | 278 | 57 | 461 | 273 | 45 | 0.587 | 0.747 | Include |
Yang, M. (2014) | 305 | 251 | 48 | 266 | 160 | 42 | 0.015 | 0.029 | Exclude |
Studies . | Case KK . | KE . | EE . | Control KK . | KE . | EE . | P-value . | Adjusted P-value . | Design . |
---|---|---|---|---|---|---|---|---|---|
Shang, Q. (2005) | 48 | 50 | 24 | 29 | 33 | 35 | 0.002 | 0.005 | Exclude |
Li, Y.J. (2010) | 47 | 39 | 7 | 52 | 36 | 13 | 0.103 | 0.180 | Include |
Lu, F.H. (2006) | 61 | 69 | 30 | 45 | 65 | 59 | 0.003 | 0.008 | Exclude |
Zhang, S.R. (2006) | 111 | 52 | 10 | 69 | 59 | 13 | 0.940 | 0.973 | Include |
Rao, D. (2005) | 84 | 41 | 20 | 59 | 19 | 66 | <0.001 | <0.001 | Exclude |
Wei, Y.S. (2006) | 124 | 84 | 17 | 101 | 103 | 26 | 0.973 | 0.973 | Include |
Zhou, Y.L. (2006) | 38 | 45 | 20 | 102 | 62 | 33 | <0.001 | <0.001 | Exclude |
Wang, M. (2005) | 96 | 61 | 8 | 91 | 90 | 18 | 0.524 | 0.734 | Include |
Jiang, H. (2002) | 202 | 226 | 100 | 60 | 66 | 87 | <0.001 | <0.001 | Exclude |
Milutinović, A. (2006) | 47 | 72 | 33 | 65 | 109 | 41 | 0.695 | 0.811 | Include |
Sarecka-Hujar, B. (2009) | 61 | 118 | 12 | 73 | 122 | 8 | <0.001 | <0.001 | Exclude |
Mohamed, A. (2010) | 20 | 37 | 43 | 2 | 11 | 37 | 0.332 | 0.516 | Include |
Luo, J.Y. (2014) | 339 | 278 | 57 | 461 | 273 | 45 | 0.587 | 0.747 | Include |
Yang, M. (2014) | 305 | 251 | 48 | 266 | 160 | 42 | 0.015 | 0.029 | Exclude |
Finally included articles are shown in bold.
Studies . | Ob = Observed genotypes . | Allele frequency . | Ex = Expected genotypes . | X2 . | P-value . | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
. | KK . | KE . | EE . | Total . | K . | E . | KK . | KE . | EE . | . | . |
Shang, Q. (2005) | 29 | 33 | 35 | 97 | 0.47 | 0.53 | 21.3 | 48.3 | 27.3 | 9.75 | 0.002 |
Li, Y.J. (2010) | 52 | 36 | 13 | 101 | 0.69 | 0.31 | 48.5 | 43.0 | 9.5 | 2.66 | 0.103 |
Lu, F.H. (2006) | 45 | 65 | 59 | 169 | 0.46 | 0.54 | 35.5 | 83.9 | 49.5 | 8.59 | 0.003 |
Zhang, S.R. (2006) | 69 | 59 | 13 | 141 | 0.70 | 0.30 | 68.8 | 59.4 | 12.8 | 0.01 | 0.940 |
Rao, D. (2005) | 59 | 19 | 66 | 144 | 0.48 | 0.52 | 32.6 | 71.8 | 39.6 | 77.90 | <0.001 |
Wei, Y.S. (2006) | 101 | 103 | 26 | 230 | 0.66 | 0.34 | 101.1 | 102.8 | 26.1 | 0.00 | 0.973 |
Zhou, Y.L. (2006) | 102 | 62 | 33 | 197 | 0.68 | 0.32 | 89.8 | 86.4 | 20.8 | 15.73 | <0.001 |
Wang, M. (2005) | 91 | 90 | 18 | 199 | 0.68 | 0.32 | 92.9 | 86.1 | 19.9 | 0.41 | 0.524 |
Jiang, H. (2002) | 60 | 66 | 87 | 213 | 0.44 | 0.56 | 40.6 | 104.8 | 67.6 | 29.19 | <0.001 |
Milutinović, A. (2006) | 65 | 109 | 41 | 215 | 0.56 | 0.44 | 66.4 | 106.2 | 42.4 | 0.15 | 0.695 |
Sarecka-Hujar, B. (2009) | 73 | 122 | 8 | 203 | 0.66 | 0.34 | 88.5 | 91.1 | 23.5 | 23.37 | <0.001 |
Mohamed, A. (2010) | 2 | 11 | 37 | 50 | 0.15 | 0.85 | 1.1 | 12.8 | 36.1 | 0.94 | 0.332 |
Luo, J.Y. (2014) | 461 | 273 | 45 | 779 | 0.77 | 0.23 | 458.3 | 278.4 | 42.3 | 0.30 | 0.587 |
Yang, M. (2014) | 266 | 160 | 42 | 468 | 0.74 | 0.26 | 255.8 | 180.4 | 31.8 | 5.98 | 0.015 |
Studies . | Ob = Observed genotypes . | Allele frequency . | Ex = Expected genotypes . | X2 . | P-value . | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
. | KK . | KE . | EE . | Total . | K . | E . | KK . | KE . | EE . | . | . |
Shang, Q. (2005) | 29 | 33 | 35 | 97 | 0.47 | 0.53 | 21.3 | 48.3 | 27.3 | 9.75 | 0.002 |
Li, Y.J. (2010) | 52 | 36 | 13 | 101 | 0.69 | 0.31 | 48.5 | 43.0 | 9.5 | 2.66 | 0.103 |
Lu, F.H. (2006) | 45 | 65 | 59 | 169 | 0.46 | 0.54 | 35.5 | 83.9 | 49.5 | 8.59 | 0.003 |
Zhang, S.R. (2006) | 69 | 59 | 13 | 141 | 0.70 | 0.30 | 68.8 | 59.4 | 12.8 | 0.01 | 0.940 |
Rao, D. (2005) | 59 | 19 | 66 | 144 | 0.48 | 0.52 | 32.6 | 71.8 | 39.6 | 77.90 | <0.001 |
Wei, Y.S. (2006) | 101 | 103 | 26 | 230 | 0.66 | 0.34 | 101.1 | 102.8 | 26.1 | 0.00 | 0.973 |
Zhou, Y.L. (2006) | 102 | 62 | 33 | 197 | 0.68 | 0.32 | 89.8 | 86.4 | 20.8 | 15.73 | <0.001 |
Wang, M. (2005) | 91 | 90 | 18 | 199 | 0.68 | 0.32 | 92.9 | 86.1 | 19.9 | 0.41 | 0.524 |
Jiang, H. (2002) | 60 | 66 | 87 | 213 | 0.44 | 0.56 | 40.6 | 104.8 | 67.6 | 29.19 | <0.001 |
Milutinović, A. (2006) | 65 | 109 | 41 | 215 | 0.56 | 0.44 | 66.4 | 106.2 | 42.4 | 0.15 | 0.695 |
Sarecka-Hujar, B. (2009) | 73 | 122 | 8 | 203 | 0.66 | 0.34 | 88.5 | 91.1 | 23.5 | 23.37 | <0.001 |
Mohamed, A. (2010) | 2 | 11 | 37 | 50 | 0.15 | 0.85 | 1.1 | 12.8 | 36.1 | 0.94 | 0.332 |
Luo, J.Y. (2014) | 461 | 273 | 45 | 779 | 0.77 | 0.23 | 458.3 | 278.4 | 42.3 | 0.30 | 0.587 |
Yang, M. (2014) | 266 | 160 | 42 | 468 | 0.74 | 0.26 | 255.8 | 180.4 | 31.8 | 5.98 | 0.015 |
P-value . | χ2 (df = 1) . |
---|---|
0.995 | 0.000 |
0.975 | 0.000 |
0.20 | 1.642 |
0.10 | 2.706 |
0.05 | 3.841 |
0.025 | 5.024 |
0.02 | 5.412 |
0.01 | 6.635 |
0.005 | 7.879 |
0.002 | 9.550 |
0.001 | 10.828 |
P-value . | χ2 (df = 1) . |
---|---|
0.995 | 0.000 |
0.975 | 0.000 |
0.20 | 1.642 |
0.10 | 2.706 |
0.05 | 3.841 |
0.025 | 5.024 |
0.02 | 5.412 |
0.01 | 6.635 |
0.005 | 7.879 |
0.002 | 9.550 |
0.001 | 10.828 |
After deleting studies with deviation from HWE and meta-analysis of included articles, we found completely different results. Genotyping data related to seven finally included articles [2–8], involving 1582 coronary heart disease (CHD) cases and 1715 controls, are shown in Table 1 (shown in bold and black color), and meta-analysis results based on five different genetics models are presented in Table 4 and Figure 1. According to our observation, we did not find a significant result in different and overall ethnicity in any genetic model. Finally, in contrast with Yin et al. [1] study and based on meta-analysis of studies in HWE, it can be concluded that ICAM-1 gene polymorphism E469K may not be related to the risk of CHD. More studies could help us to get a definitive result.
CHD risk associated with the K469E polymorphism for K/E + K/K versus E/E genotype
Classification . | Allelic (K vs. E) OR [95% CI] . | Q test P-value . | K/E + K/K vs. E/E OR [95% CI] . | Q test P-value . | KK vs. K/E + E/E OR [95% CI] . | Q test P-value . | K/E vs. K/K + E/E OR [95% CI] . | Q test P-value . |
---|---|---|---|---|---|---|---|---|
Chinese | 1.23 [0.84–1.78] | 0.01 | 1.32 [0.79–2.22] | 0.03 | 1.25 [0.79–1.98] | 0.01 | 0.89 [0.63–1.26] | 0.01 |
Caucasian | 1.79 [0.50–6.44] | 0.01 | 1.75 [0.41–7.52] | 0.01 | 2.14 [0.39–11.7] | 0.03 | 1.26 [0.55–2.93] | 0.06 |
Overall | 1.33 [0.95–1.85] | 0.01 | 1.44 [0.89–2.33] | 0.01 | 1.32 [0.89–1.96] | 0.01 | 0.95 [0.71–1.27] | 0.01 |
Classification . | Allelic (K vs. E) OR [95% CI] . | Q test P-value . | K/E + K/K vs. E/E OR [95% CI] . | Q test P-value . | KK vs. K/E + E/E OR [95% CI] . | Q test P-value . | K/E vs. K/K + E/E OR [95% CI] . | Q test P-value . |
---|---|---|---|---|---|---|---|---|
Chinese | 1.23 [0.84–1.78] | 0.01 | 1.32 [0.79–2.22] | 0.03 | 1.25 [0.79–1.98] | 0.01 | 0.89 [0.63–1.26] | 0.01 |
Caucasian | 1.79 [0.50–6.44] | 0.01 | 1.75 [0.41–7.52] | 0.01 | 2.14 [0.39–11.7] | 0.03 | 1.26 [0.55–2.93] | 0.06 |
Overall | 1.33 [0.95–1.85] | 0.01 | 1.44 [0.89–2.33] | 0.01 | 1.32 [0.89–1.96] | 0.01 | 0.95 [0.71–1.27] | 0.01 |
Classification . | K/K vs. E/E OR [95% CI] . | Q test P-value . | K/K vs. K/E OR [95% CI] . | Q test P-value . | K/E vs. E/E OR [95% CI] . | Q test P-value . | . | . |
---|---|---|---|---|---|---|---|---|
Chinese | 1.47 [0.75–2.88] | 0.01 | 1.20 [0.78–1.83] | 0.01 | 1.06 [0.78–1.43] | 0.40 | ||
Caucasian | 2.48 [0.27–22.49] | 0.01 | 1.19 [0.75–1.88] | 0.24 | 1.49 [0.43–5.10] | 0.01 | ||
Overall | 1.57 [0.88–2.80] | 0.01 | 1.22 [0.86–1.74] | 0.03 | 1.11 [0.86–1.42] | 0.01 |
Classification . | K/K vs. E/E OR [95% CI] . | Q test P-value . | K/K vs. K/E OR [95% CI] . | Q test P-value . | K/E vs. E/E OR [95% CI] . | Q test P-value . | . | . |
---|---|---|---|---|---|---|---|---|
Chinese | 1.47 [0.75–2.88] | 0.01 | 1.20 [0.78–1.83] | 0.01 | 1.06 [0.78–1.43] | 0.40 | ||
Caucasian | 2.48 [0.27–22.49] | 0.01 | 1.19 [0.75–1.88] | 0.24 | 1.49 [0.43–5.10] | 0.01 | ||
Overall | 1.57 [0.88–2.80] | 0.01 | 1.22 [0.86–1.74] | 0.03 | 1.11 [0.86–1.42] | 0.01 |
Competing Interests
The authors declare that there are no competing interests associated with the manuscript.