A cross-sectional study on the relationships among the polymorphism of period2 gene, work stress, and insomnia

Work-related stress factors are commonly considered to be increasing the risk of insomnia. But the association between circadian-rhythm gene period2 (per2) and insomnia remains unknown. The paper aimed to examine the relationships among the polymorphism in rs7602358 of Per2 gene, work stress, and insomnia.

In the cross-sectional study of a total of 364 Chinese workers recruited, 218 had insomnia tested by the Athens Insomnia Scale (AIS-5). Work stress was assessed using the General Job Stress Questionnaire (GJSQ). Per2 genotypes were determined by SNaPshot technology. Unconditional logistic regression analysis was used to examine the interaction between polymorphism of Per2 and work stress in insomnia.

The genotype AC or allele C of Per2 significantly increased the risk of insomnia (OR, 5.41; 95 % CI, 2.23-13.1) (OR, 3.29; 95 % CI, 1.55-6.98). Compared to low work stress, high work stress had a higher risk of insomnia (OR, 2.73; 95 % CI, 1.77-4.22). A significant interaction between Per2 and work stress in the risk of insomnia was found. Compared to workers with low work stress and genotype AA, those with high work stress and genotype AC had a higher risk of insomnia (OR, 15.12; 95 % CI, 3.46-66.09).

The effect of genotype AC or allele C of Per2 on insomnia was relatively stronger than that of high work stress, suggesting that individual's susceptibility should be taken into consideration when intervening and controlling insomnia of workers.