Abstract
BACKGROUND: Sleep represents a pivotal circadian physiological process that is indispensable for sustaining a normal physiological milieu within the body. The potential role of sleep disorders in contributing to the onset and progression of cancer remains elusive, prompting this study to delve into the intricate relationship between sleep disturbances, specifically insomnia, and the risk of developing prostate cancer. METHODS: This cross-sectional study investigated the relationship between sleep disorders and prostate cancer using weighted multivariate adjusted logistic regression analysis of data from two cycles of the National Health and Nutrition Examination Survey (NHANES) database (2005-2008). Additionally, a two-sample Mendelian randomization (MR) analysis was conducted using open-access genome-wide association studies (GWAS) data to assess the causal link. RESULTS: After correcting for potential confounders, the study showed that insomnia [odds ratio (OR) =1.01; 95% confidence interval (CI): 1.00-1.03; P=0.041] was positively associated with the prevalence of prostate cancer. The same findings were shown in the MR analysis of inverse variance weighting (IVW) and weighted median (WM) (OR =1.346, 95% CI: 1.048-1.730, P=0.02; OR =1.446, 95% CI: 1.030-2.030, P=0.03). After segmentation by sleep duration 0-4, 4-8, and 8+ hours, it was found that in the unadjusted model, the risk of prostate cancer was reduced in those with 8+ hours of sleep compared to those with 0-4 hours of sleep (OR =0.94; 95% CI: 0.88-1.00; P=0.047), and the total prostate specific antigen (tPSA) of the patients gradually increased with increasing sleep duration (OR =1.35, 95% CI: 1.06-1.71, P=0.02; OR =2.62, 95% CI: 1.61-4.24, P<0.001). CONCLUSIONS: Insomnia is associated with an increased risk of prostate cancer, highlighting a causal relationship that is independent of age and emphasizing the importance of considering sleep disorders in prostate cancer research.