Circadian Disruption & Chronic Disease Research Program (CIRCADIA)
Our daily rhythms of sleep, activity, light exposure, and other behaviours are closely coordinated with the body's internal circadian system. Modern life increasingly disrupts these rhythms through night shift work, artificial light at night, irregular sleep patterns, and changing environmental conditions. At the same time, insufficient and disrupted sleep are increasingly recognized as important contributors to long-term health.
CIRCADIA is a collaborative research program investigating how sleep and circadian disruption influence the development of chronic disease. We combine population-based epidemiology with human mechanistic studies to understand not only whether disrupted sleep and circadian rhythms affect health, but the biological pathways through which these effects occur.
Our research
Our work spans three interconnected areas:
1. Sleep and circadian disruption in populations
We study how sleep duration, quality, timing and regularity, as well as exposures that disrupt circadian rhythms, including night shift work and artificial light at night, relate to cancer and other chronic disease outcomes.
2. Understanding biological mechanisms
We use human mechanistic studies and molecular epidemiology to investigate how sleep and circadian disruption affect biological processes relevant to disease. Our work has examined melatonin and cortisol rhythms, oxidative DNA damage and repair, epigenetic alterations, and cardiometabolic pathways, with ongoing research extending to the gut microbiome and other molecular markers.
3. Emerging threats to sleep and circadian health
We are interested in how changing environmental and societal conditions may disrupt sleep and circadian biology. This includes emerging work examining nighttime heat and sleep disruption as a potential pathway linking climate change with long-term health.
Our approach
A central goal of CIRCADIA is to bridge population science and human mechanistic research.
Large population studies can identify patterns between sleep, circadian disruption and disease that unfold over many years. Human mechanistic studies can help explain these observations by identifying biological changes that occur much earlier in the disease process. Bringing these approaches together can strengthen our understanding of how circadian disruption affects health and identify potential targets for prevention. Ultimately, we aim to generate evidence that can inform interventions, workplace practices, environmental policies and other strategies to protect sleep and circadian health.
Current research
Current and recent CIRCADIA research includes:
Night shift work, circadian disruption and chronic disease
Melatonin, oxidative DNA damage and DNA repair among night shift workers
Night shift work and the gut microbiome
Circadian disruption and epigenetic regulation
Artificial light at night and cancer risk
Sleep, the built environment and long-term health
Nighttime heat, sleep disruption and chronic disease
Program leadership
Jennifer A. Ritonja, PhD
Parveen Bhatti, PhD
Staff
Photo by @anthonymaw
