Long sleep duration and mortality among U.S. cancer survivors: NHIS-NDI linkage

Introduction: Sleep duration has been associated with mortality among cancer survivors, but whether this association differs by baseline cardiometabolic health remains unclear. We examined the association between sleep duration and all-cause and cause-specific mortality among United States adult cancer survivors and evaluated whether hypertension modified these associations. Materials and methods: We analyzed 2203 adult cancer survivors from the 2004 National Health Interview Survey linked to National Death Index mortality data through 31 December 2019. Hypertension was defined by self-reported physician diagnosis. Survey-weighted Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause, cancer-specific, cardiovascular disease-related, and other-cause mortality. Models were sequentially adjusted for sociodemographic, behavioral, clinical, and cancer-related factors. Effect modification was assessed using sleep duration × hypertension interaction terms and subgroup analyses by hypertension status. Results: Long sleep duration (≥9 h) was associated with higher all-cause mortality (HR: 1.86, 95% CI: 1.54–2.24), cancer-specific mortality (HR: 1.84, 95% CI: 1.35–2.51), cardiovascular disease-related mortality (HR: 1.66, 95% CI: 1.21–2.29), and other-cause mortality (HR: 2.03, 95% CI: 1.51–2.74) in unadjusted models. These associations were attenuated after sequential adjustment and were no longer statistically significant in fully adjusted models. Hypertension did not significantly modify the association between sleep duration and mortality across outcomes (interaction p > 0.05). In descriptive subgroup analyses, long sleep duration remained associated with higher all-cause mortality (HR: 1.56, 95% CI: 1.10–2.22) and other-cause mortality (HR: 1.88, 95% CI: 1.04–3.40) among normotensive survivors, whereas associations among hypertensive survivors were attenuated after full adjustment. Conclusions: Associations between long sleep duration and elevated mortality risk among cancer survivors may be partially explained by sociodemographic, behavioral, clinical, and cancer-related factors. Hypertension did not significantly modify these associations. However, long sleep duration may still serve as a clinically accessible marker of vulnerability in survivorship care.