Past shift work, melatonin receptor gene polymorphisms, and hyperhomocysteinemia among retired workers: The Dongfeng-Tongji cohort study.

OBJECTIVES

This study aims to investigate the associations between past shift work and hyperhomocysteinemia and further explore the modification effects of MTNR1A rs12506228 and MTNR1B rs10830963 (2 single-nucleotide polymorphisms in melatonin receptor genes) on this association.

METHODS

Based on the data of 14,043 retirees from the Dongfeng-Tongji cohort, multivariate logistic regression was used to analyze the association between past shift work duration and hyperhomocysteinemia, and gene-environment interaction analysis was performed.

RESULTS

Among 14,043 retirees from the Dongfeng-Tongji cohort, we found that retirees with longer durations of past shift work were significantly associated with higher odds of hyperhomocysteinemia (odds ratio and 95% confidence interval for per 5-year increase: 1.04 [1.02-1.06], P<.001). Furthermore, MTNR1B rs10830963 significantly exacerbated the effect of long-duration past shift work on hyperhomocysteinemia odds (P-trend<.001, P-interaction=.01), and MTNR1A rs12506228 had a joint effect with past shift work on hyperhomocysteinemia odds (P-trend<.001, P-interaction=.89).

CONCLUSIONS

The long-term hazard of shift work on hyperhomocysteinemia persisted from past to post retirement, and such association could be modified by MTNR1B rs10830963.