Term of Award

Fall 2023

Degree Name

Doctor of Public Health in Epidemiology (Dr.P.H.)

Document Type and Release Option

Dissertation (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.


Department of Biostatistics, Epidemiology, and Environmental Health Sciences

Committee Chair

Jian Zhang

Committee Member 1

Kelly Sullivan

Committee Member 2

Lili Yu


Due to variations in cut points used to classify sleep duration variables and the incompatibility of study protocols, previous studies have provided inconsistent results on the relationship between sleep patterns and all-cause deaths. Therefore, the research focus has now shifted from examining the relationship to more accurately identifying the population at high risk to promote overall physical and mental well-being. We hypothesized that Metabolic syndrome (MetS) may elevate the risk of death among adults with unhealthy sleep patterns, and assessed the relationship between sleep duration and all-cause mortality among participants stratified by MetS status. The study sample consisted of 27,836 participants aged ≥20 who participated in the National Health and Nutrition Examination Survey (2005-2018). The study participants were classified into three sleep duration categories according to sleep hours recommended by the National Sleep Foundation: short sleep (SS, < 7 hours), long sleep (LS, >9 hours for adults aged 18-64 y, and >8 hours for adults ≥65 y), otherwise as with recommended sleep (RS) hours. The Cox Proportional Hazard model was used to estimate the association between sleep duration and all-cause mortality. 2,803 deaths occurred over an average follow-up period of 91.9 person-months. The participants in the LS group experienced excessive risk of death and survived 2 years shorter than the SS and RS groups. In the MetS group, the LS group had a 41% higher hazard of mortality compared to the RS group [HR: 1.41 (95% CI: 1.16-1.72)]. Similar results were observed among the non-MetS group [LS, HR= 1.75 (1.40-2.19)]. No significant association was observed in the short sleep group in either stratum. Our research concluded that healthy sleep habits are equally important for everyone, regardless of their metabolic health status; therefore, it might be more cost-effective if sleep health promotion is performed at the community level.

Research Data and Supplementary Material


Available for download on Tuesday, November 14, 2028