The Relationship of Sleep Duration with Ethnicity and Chronic Disease in a Canadian General Population Cohort

Abstract

Study Objectives

Sleep duration is an important marker of sleep quality and overall sleep health. Both too little and too much sleep are associated with poorer health outcomes. We hypothesized that ethnicity-specific differences in sleep duration exist.

Methods

This cross-sectional study utilized questionnaire data from the Ontario Health Study (OHS), a multi-ethnic population-based cohort of Canadian adult residents aged 18 to 99 years, who provided medical, socio-demographic, and sleep information. Generalised linear models were used to investigate the association of sleep duration with ethnicity.

Results

The study sample consisted of 143,307 adults (60.4% women). The sample was multi-ethnic, including self-identified Aboriginal, Arab, Black, Chinese, Filipino, Hispanic, Japanese, Korean, Mixed (>1 ethnicity), South Asian, South-East Asian, West Asian, and White ethnicities. Univariate analyses found that mean sleep duration compared to the White reference group (7.34 hours) was shorter in the Filipino (6.93 hours, 25 min less), Black (6.96 hours, 23 min less), Japanese (7.02 hours, 19 min less), Chinese (7.23 hours, 7 min less), and Mixed (7.27 hours, 4 min less) groups (all P<0.001). Mean sleep duration was shorter in men (7.25 hours) compared to women (7.37 hours) in the cohort as a whole (P<0.001), and in all ethnic groups (P<0.001). Multivariate analyses, adjusted for a wide range of potential risk factors, and analysis of sleep duration as a categorical variable (“short”, “average”, and “long” sleepers) confirmed these relationships. Both sleep duration and ethnicity were independent significant predictors of a range of physician-diagnosed morbidities including diabetes, stroke, and depression.

Conclusion

Important differences exist in sleep duration between ethnic groups and may contribute to observed health disparities. Our results highlight the need for ethnicity-specific targeted education on the importance of prioritizing sleep for good health, and the need to account appropriately for ethnicity in future epidemiological, clinical, and translational research into sleep and related conditions.

Keywords:

• sleep health
• sleep duration
• ethnicity
• population health
• health disparity

Acknowledgments

We thank Woganee Filate for technical assistance. We also thank the participants in the Ontario Health Study.

Disclosure

Financial disclosure: This work was supported by the Ontario Institute for Cancer Research; Cancer Care Ontario; Public Health Ontario and the Canadian Partnership Against Cancer. Amy Reynolds reports financial reimbursement from Sealy Australia to provide expert scientific commentary on findings of the Sealy Global Sleep Census. The authors report no other conflicts of interest in this work.

Non-financial disclosure: The data used for this research was made available by the Ontario Health Study with the financial support from the Canadian Partnership Against Cancer, Health Canada and the Ontario Institute for Cancer Research. The views expressed herein represent the views of the authors and do not necessarily represent the views of Health Canada or the Government of Ontario.