Sleep duration and prostate cancer-specific mortality in the Southern Community Cohort Study

Sleep patterns may affect metabolic and behavioral processes, which subsequently could be linked to cancer mortality. However, the relationship between sleep patterns and prostate cancer-specific mortality remains unclear. We evaluated the association of sleep and prostate cancer-specific mortality and investigated whether race/ethnicity influences the association.

The Southern Community Cohort Study (SCCS), a prospective cohort study, recruited participants from 12 Southeastern states between March 2002 and September 2009. The cohort included 34,166 males, predominantly Black/African American. Sleep exposures were measured via a baseline questionnaire. Cox Proportional hazards models were used to estimate associations between sleep and prostate cancer-specific mortality and were adjusted for important potential confounders.

During follow-up (median 15.9 years), 225 men died from prostate cancer. Longer sleep duration (≥ 9 hours) on weekends versus 7-8 hours was suggestively associated with an increased risk of prostate cancer-specific mortality (hazard ratio (HR)= 1.44, 95% confidence interval (CI): 1.02-2.03). When stratified by race, longer sleep duration was suggestively associated with an increased risk of prostate cancer mortality for both Black and White men, although the associations were insignificant. Overall sleep duration and restless sleep were not associated with prostate cancer-specific mortality.

Men reporting ≥ 9 hours of weekend sleep had an elevated risk of prostate cancer-specific mortality compared with those sleeping 7-8 hours. Stratified analysis suggests an increased risk of prostate cancer-specific mortality among both Black men and White men with ≥ 9 hours of sleep versus 7-8 hours, though estimates were imprecise due to small event numbers.