IJCS | Volume 33, Nº3, May / June 2020

258 Silva et al. Polymorphisms in acute coronary syndrome Int J Cardiovasc Sci. 2020; 33(3):254-262 Original Article Table 3 – Analysis of the association of SNPs in the IL8 and IL16 genes with the risk factors for ACS SNP / risk factors p Odds ratio IC 95% IL8 (rs4073) Smoking 0.39 0.73 0.36 – 1.50 Diabetes 0.92 1.03 0.53 – 2.04 Hypertension 0.49 0.73 0.30 – 1.79 Dyslipidemias 0.31 1.43 0.72 – 2.86 IL16 (rs11556218) Smoking 0.94 0.97 0.46 – 2.06 Diabetes 0.22 1.54 0.76 – 3.12 Hypertension 0.002 0.26 0.12 – 0.62 Dyslipidemias 0.01 2.68 1.19 – 6.04 SNP: Single Nucleotide Polymorphism; P: multivariate logistic regression; CI: Confidence Interval. Besides age, gender is also important in the epidemiologyofACS.According toMaas andAppelman, 32 cardiovascular diseases, where ACS is included, usually manifest later in women than in men, partly because of differences in exposure to risk and hormonal factors. 33,34 In our study, males accounted for 76.5% of ACS patients. Similar datawere obtained byHuang et al., 15 and Bray et al., 35 who observed the frequency of 80.4% and 68.0%ofmale inACS patients of their studies, respectively. Smoking, diabetes, hypertension and dyslipidemias are considered important in increasing the risk for ACS, however, most of the patients in the present study were neither smokers nor diabetics in both groups (with or without ACS). These data corroborate the study by Guedes et al., 36 inwhich the majority of Brazilian patients with CDwere not smokers (93.3%). In a study by Vogiatzi et al., 5 with Greek patients diagnosed with ACS, the majority was not diabetic (64.3%). Despite this, diabetes and smokingmay not have their importance excluded as risk factors for ACS. Generally, the majority of patients (with or without ACS) had systemic arterial hypertension. These results corroborate the data obtained from patients with ACS in different countries (Australia, Pakistan, Mexico and Japan) who indicated that the majority of the patients were hypertensive, varying between 56.5% in Japan and 68.0% in the Mexico. 14,35,37,38 For the Ministry of Health, this disease is responsible for at least 25% of the deaths due to ACS. 39 In the present study it was verified that the majority of patients with ACS are dyslipemic (64.0%), similar data were verified by Feijó et al., 40 Rodrigues et al., 41 and Andrade et al., 42 who studied Brazilian patients with CDs and found that 50.5%, 73.9% and 60.1%, respectively, were dyslipemic. The data about risks factors reinforce that this disease has a multifactorial character. Thereby the genetic component directly participates in the predisposition to ACS. Regarding the polymorphism in the IL8 gene (rs4073), we observed a higher frequency of the AT heterozygous genotype in the three groups analyzed. Similarly, in a study by Zhang et al., 6 a prevalence of AT genotype was 47.4% in patients withACS and 45.9% in the control group. For the SNP in the IL16 gene (rs11556218), a difference in heterozygous TG genotype frequencies was observed between the group of patients with ACS and the group of blood donors (p = 0.0026). In addition, carriers of the G mutant allele were more present in blood donors than in patients withACS, suggesting that this allele may have a protective action in ACS. Discordant data were found in a study by Chen et al.. 8 in which the G allele was more frequent in patients with ACS (84.9%) than in the control group (64.2%). However, the authors point that the lack of success in replicating the positive result in other populations is the main problem for genetic association studies. 8 When comparing the serum levels of IL-16 cytokine, donor individuals presented higher values than patients withACS (p = 0.04). In addition, among the blood donors, the G (TG + GG) allele presented higher IL-16 values (p = 0.01). These results corroborate the data obtained by Gronberg et al., 11,43 where the presence of IL-16 on the carotid plaque is associated with a decreased risk of cardiovascular events in studies performed with a Swedish population. This is due to the stabilization of the atherosclerotic plaques, avoiding theACS disease. 11,43 The cytokine IL-16 has been described as a pro- inflammatory cytokine. However, there are few studies supporting its possible anti-inflammatory function, identified by the present study. 11,43 In addition, one hypothesis for the lack of association found between ACS and non-ACS patients