Background: Job strain and the Arg389Gly polymorphism in the adrenergic beta1-receptor gene have been linked to hypertension. We aimed to study whether there is an interaction between the Arg389Gly polymorphism and job strain and its components (job demand and decision latitude) in relation to blood pressure.
Methods: From the Malmö Diet and Cancer population cohort, 6095 individuals were randomly selected to be followed regarding cardiovascular risk factors. From this group, employed individuals with baseline data regarding work characteristics were included (1338 men and 1707 women). Determination of adrenergic beta1-receptor Arg389Gly polymorphism was possible in 1271 men and 1601 women, and these individuals formed the study group.
Results: Men with the combination of Arg389Arg and job strain were more often on antihypertensive medication (P = 0.04), whereas blood pressure was not significantly higher, in comparison with those without both of these two factors. The interaction term genotype x job strain was borderline significant for systolic blood pressure (P = 0.07) after adjustments for age, country of birth, and job status. The demand score showed significant interaction in men with genotype (P = 0.01 for systolic blood pressure and P = 0.009 for diastolic blood pressure) after adjustments for age, country of birth, job status, antihypertensive treatment, and BMI. Men with the Gly389 allele had lower blood pressure with increasing demand score (P = 0.001), whereas men homozygous for the Arg389 allele had lower blood pressure with increasing latitude score (P = 0.03). In women, those with job strain tended to have higher blood pressure than those without job strain, among carriers of Arg389Arg and Arg389Gly genotype.
Conclusion: Men with job strain and the Arg389Arg polymorphism were more often on antihypertensive treatment than other men. Significant interactions between the Arg389Gly polymorphism and aspects of job stress are described, but the absolute blood pressure differences are small. Considering the commonness of the polymorphism, stress, and hypertension further studies are indicated.