Background Hypertension is influenced by both genes and environment. At present, most studies on the relationship among occupational stress, polymorphisms of ATP binding cassette subfamily A member 1 (ABCA1) or angiotensinogen (AGT) genes, and hypertension focus on single gene or single environmental effects.

Objective To investigate the relationship of potential interactions between ABCA1 and AGT gene polymorphisms and occupational stress with the prevalence of hypertension.

Methods A total of 198 hypertensive patients were selected as the case group from the 1200 oilfield workers in Karamay Oilfield in 2018 with random cluster sampling method, and the control group was selected as 1∶1 matched subjects for sex, age (±3 years), and ethnicity, after excluding blood samples, questionnaires, or DNA purity (concentration) that did not meet the inclusion criteria. Finally, 153 workers in the hypertension case group and 153 workers in the control group were determined. A questionnaire was used to collect general information of the oilfield workers, and the Occupational Stress Inventory Revised Edition (OSI-R) was used to evaluate occupational stress. Polymerase chain reaction-restriction fragment length polymorphism technology was used to detect the genotypes of V825I and R219K loci of ABCA1 as well as M235T and T174M loci of AGT. The gene-gene interaction of ABCA1 and AGT and the relationship between the interaction of gene-occupational stress and the prevalence of hypertension were analyzed by generalized multi-factor dimensionality reduction method.

Results The difference of reported occupational stress between the hypertension case group and the control group was statistically significant (P＝0.001), and the reporting rate of high occupational stress in the case group (65.4%) was higher than that in the control group (47.7%). The genotype and allele distributions of ABCA1 V825I, ABCA1 R219K, and AGT M235T between the hypertension case group and the control group were significantly different (P<0.05). The results of conditional logistic regression analysis showed that VI and II genotypes at V825I locus of ABCA1 (OR_VI=1.682, 95%CI: 1.099-2.573; OR_II=1.708, 95%CI: 1.045-2.790), TT genotype at M235T locus of AGT (OR=1.645, 95%CI: 1.022-2.647), and high occupational stress (OR=2.642, 95%CI: 1.228-5.686) increased the risks for hypertension (P<0.05). There was no significant correlation between ABCA1 R219K or AGT T174M polymorphisms and the prevalence of hypertension (P>0.05). The gene-gene interactions between ABCA1 V825I and R219K loci and AGT M235T locus were associated with hypertension (accuracy on training and test sets was 0.68 and 0.63, respectively, with a cross-validation coefficient of 10/10, P<0.05), and ABCA1 V825I locus positively interacted with AGT M235T locus. The gene-environment interactions among ABCA1 V825I and R219K loci, AGT M235T locus, and occupational stress were associated with hypertension (accuracy on training and test sets was 0.74 and 0.63, respectively, with a cross-validation coefficient of 10/10, P<0.05), and AGT M235T locus negatively interacted with occupational stress.

Conclusion Genotype VI and II of V825I locus at ABCA1, genotype TT of M235T locus at AGT, and high occupational stress may be risk factors for oilfield workers’ hypertension in Karamay, and the interactions of gene-gene and gene-environment among ABCA1 and AGT gene polymorphisms and occupational stress may be associated with hypertension.