The research team, led by Shirmin Bintay Kader of the University of Saskatchewan and Jubayer Mumin of the Karolinska Institute, used the CCHS microdata to assess sleep duration through a single self-reported question: the number of hours per night usually spent sleeping. Responses were categorized into three groups: between 7 and 9 hours (the recommended range for adults according to the American Academy of Sleep Medicine and Sleep Research Society), short sleep duration of less than 7 hours, and long sleep duration of more than 9 hours. The primary predictor was the number of chronic conditions, aggregated from 12 recorded conditions including asthma, COPD, arthritis, hypertension, hyperlipidemia, heart disease, stroke, diabetes, cancer, allergies, mood disorder, and anxiety. Participants were grouped into no chronic condition, one, two, or three or more chronic conditions.

The findings are striking. Approximately 41% of respondents reported short sleep duration, while 7.73% reported long sleep duration. Only about half of the sample (51.31%) fell within the recommended 7–9 hour range. Compared with respondents who had no chronic conditions, those with three or more co-existing chronic conditions were 1.70 times more likely to report short sleep duration (95% CI: 1.52–1.91) and 2.58 times more likely to report long sleep duration (95% CI: 1.96–3.41) after adjusting for sociodemographic, socioeconomic, and behavioral factors including age, sex, ethnicity, marital status, education, income, employment, immigration status, body mass index, physical activity, smoking, and alcohol consumption.

What makes these results particularly compelling is the graded nature of the association. The odds of both short and long sleep duration increased progressively with each additional chronic condition. Participants with one chronic condition had modestly elevated odds (adjusted odds ratio 1.19 for short sleep), those with two conditions showed higher odds (1.38 for short sleep, 1.37 for long sleep), and those with three or more conditions showed the strongest association. The p-value for trend across ordinal multimorbidity categories was statistically significant at less than 0.001, indicating a dose-response relationship between chronic disease burden and abnormal sleep patterns.

The biological plausibility of this link rests on several mechanisms. Chronic conditions are associated with pain, inflammation, hormonal dysregulation, autonomic nervous system activation, and medication side effects, all of which can disrupt normal sleep architecture. Psychological distress, functional limitations, and reduced physical activity resulting from chronic illness may further compromise sleep duration and quality. Conversely, short sleep has been shown to dysregulate inflammatory pathways, impair glucose metabolism, and create autonomic imbalance, potentially contributing to the development and exacerbation of chronic diseases. This bidirectional relationship means the association observed here may reflect disease disrupting sleep, sleep accelerating disease, or both processes reinforcing each other in a feedback loop.

The sociodemographic patterns in the data add further nuance. Short sleep duration was most prevalent among participants aged 40–64 years (43.66%), while long sleep duration was highest among those aged 65 and above (15.97%). Non-White respondents reported a higher prevalence of short sleep (47.90%) than White respondents (38.93%), and immigrants reported more short sleep (44.88%) than non-immigrants (39.71%). Long sleep was more common among widowed, divorced, or separated respondents (11.01%) than married respondents (6.74%), and among those with less than secondary education (16.51%) compared with post-secondary degree holders (5.61%). Unemployed respondents reported long sleep at 13.24% versus 4.36% for employed respondents, and those with no physical activity reported long sleep at 14.09% versus 5.52% for those exceeding recommended activity levels.

The prevalence of multimorbidity itself varied sharply across population groups. Nearly one-third of respondents aged 65 or above (29.34%) reported three or more chronic conditions, compared with only 2.26% of those under 40. Obese participants reported nearly three times the prevalence of three or more conditions (19.19%) than normal or underweight respondents (6.45%). Those with no income (20.01%), less than secondary education (23.37%), and no employment (22.48%) also showed elevated multimorbidity. These patterns suggest that the sleep–multimorbidity association is embedded within broader structural inequalities in health.

The study’s cross-sectional design means causal and temporal relationships cannot be established, and the direction of association should be interpreted with caution. Sleep-related data were collected from a subsample comprising approximately 50% of the original survey respondents, which may have introduced selection bias and underrepresentation of certain groups, particularly those in larger metropolitan areas and territories. Self-reported sleep duration from a single question may reflect time in bed rather than true sleep and does not capture insomnia, sleep quality, napping, or sleep regularity. The simple count of chronic conditions assumes equal contribution of all conditions despite differences in clinical severity and health impact, and obesity was excluded from the multimorbidity definition although it was adjusted for as a confounder, potentially underestimating the overall disease burden associated with abnormal sleep.

Despite these limitations, the findings carry significant implications for public health surveillance and clinical practice. The high prevalence of short sleep duration among Canadian adults—40.96%—exceeds rates reported in other high-income countries such as Luxembourg, where only 5% reported sleeping less than 6 hours, and Australia, where short sleep was similarly uncommon. The authors suggest that structural and behavioral factors, including work-related stress, longer commuting time, extensive screen exposure, and the growing prevalence of shift work, may account for these differences. The sharp increase in multimorbidity prevalence over time—from 3.9% of Canadians having more than three chronic conditions in 2015 to 11.65% in this 2017–2018 sample—likely reflects population aging, improved survival from chronic disease, enhanced detection, evolving disease classification, and lifestyle changes including reduced physical activity and sedentary behavior.

The authors recommend incorporating sleep duration into epidemiological research and public health surveillance of chronic conditions, and call for future longitudinal studies to clarify the temporal and potentially bidirectional relationship between sleep and multimorbidity. They also suggest examining vulnerable populations—older adults, immigrants, racialized groups, and individuals with obesity—separately to identify groups carrying a higher burden of both multiple chronic conditions and abnormal sleep duration. As multimorbidity continues to rise globally, understanding how the accumulation of chronic disease reshapes sleep patterns may prove essential for designing interventions that address both conditions simultaneously rather than treating them as isolated health problems.

Subject of Research: Sleep Health

Article Title: Association between sleep duration and co-existing chronic conditions in adults: insights from the 2017–2018 Canadian Community Health Survey

Article References: Kader, S. B., Mumin, J., Shakurun, N., Zinia, S. N., Schipper, Z., Ritu, N. S., Haque, S. A., & Rahman, M. M. (2026). Association between sleep duration and co-existing chronic conditions in adults: insights from the 2017–2018 Canadian Community Health Survey. Frontiers in Sleep, 5, Article 1714511. https://doi.org/10.3389/frsle.2026.1714511

Image Credits: AI Generated

DOI: 10.3389/frsle.2026.1714511

Keywords: sleep duration, multimorbidity, chronic conditions, Canadian Community Health Survey, sleep health, epidemiology, public health, cross-sectional study, Association, between, sleep, duration