Abstract: Objective To investigate the association between sleep duration and risk of colorectal cancer incidence in women.Methods All the female employees including the female retirees of the Kailuan Group who completed routine physical examinations were recruited in the Chinese Kailuan female cohort.Information on lifestyle such as sleep duration and smoking status was collected at the baseline investigation,as well as the information of newly-diagnosed colorectal cancer cases during the follow-up period.Multivariable Cox proportional hazards regression models were used to evaluate the association between levels of sleep duration and risk of colorectal cancer.Results A total of 24688 females were recruited in the study and there were 108020.76 person-years of follow-up and 4.38 years of average follow-up period.During follow-up,32 colorectal cancer cases were identified in the present cohort.Compared with 7h of sleep duration,the hazard ratio and 95% confidence intervals of colorectal cancer were 0.41(0.14~1.22)and 0.56(0.23~1.40)for short(≤6h)and long(≥8h)sleep duration,respectively,after adjustment for potential confounding factors such as age.Similar results were obtained when analysis was conducted in subgroups stratified by snoring or baseline BMI.Conclusion It is still not sure that sleep duration is significantly associated with risk of colorectal cancer in Chinese female.

Key words: Colorectal neoplasms, Sleep duration, Prospective study