Sex-specific cancer risk associated with insomnia: a prospective cohort study using the Korean genome and epidemiology study (KoGES) data

Abstract

The interaction effect of sex and insomnia on the risk of cancer remains unclear. Our study aimed to examine the association between insomnia and cancer development, and through stratified analysis, to determine if this association is modified based on sex. We used the Korean Genome Epidemiology Study (KoGES), which initiated two distinct prospective cohort investigations in 2001. The main exposure variable are sex and insomnia and the main outcome is cancer occurrence. The occurrence of cancer was considered the main outcome, and Cox regression analysis was utilized to estimate hazard ratios and 95% confidence interval. Additionally, stratified analysis was conducted to evaluate the interaction effect of sex and insomnia on cancer risk. In our study, the incidence of cancer per 1000 person-years was 5.23 in the insomnia group and 5.33 in the non-insomnia group, with no significant difference in adjusted hazard ratio (aHR: 1.01 (0.81–1.26)). Stratifying by sex, incidence rates were 4.86 for males and 5.72 for females per 1000 person-years, with females presenting a significantly higher aHR (1.30 (1.03–1.71)). No significant interaction was observed for both “insomnia × sex” and “sex × insomnia”. Notably, females on insomnia medication had a substantially increased cancer risk (aHR: 4.06 (1.95–17.24)). Our study revealed that females, especially those undergoing insomnia medication treatment, exhibited a heightened cancer risk, though insomnia alone did not significantly influence this risk. These findings suggest a potential protective effect of male gender against cancer incidence.

Keywords

• cancer
• insomnia
• sex