Tejal Somvanshi
New research reveals that irregular sleep patterns significantly increase cardiovascular risks, even when people get enough sleep. The study, published in the Journal of Epidemiology & Community Health, analyzed data from 72,269 UK adults aged 40-79.
Sleep Regularity Emerges as a Critical Factor
The study uses the Sleep Regularity Index (SRI), which scores sleep patterns from 0 to 100. Participants with SRI scores below 71.6 showed a 26% higher risk of major cardiovascular events, including heart attacks and strokes. Even moderately irregular sleepers (SRI 71.6-87.3) faced an 8% increased risk.
“Sleep regularity may be more relevant than sufficient sleep duration in modulating major adverse cardiovascular event risk,” states Jean-Philippe Chaput, PhD, senior scientist at the Children’s Hospital of Eastern Ontario Research Institute and lead author.
Key Findings
The research tracked participants for an average of 7.8 years, revealing:
- Regular sleepers (61%) met recommended sleep duration compared to irregular sleepers (48%)
- Irregular sleep increased heart failure risk by 45%
- An SRI score of 77.1 reduced cardiovascular risk by 15%
- The median SRI score of 80.8 decreased risk by 18%
Sleep Duration Not Enough
The study challenges conventional wisdom about sleep duration. Even participants meeting recommended sleep hours (7-9 hours for ages 18-64, 7-8 hours for 65+) faced increased cardiovascular risks if their sleep patterns remained irregular.
“While both adequate sleep duration and regular sleep patterns are important, our findings show that meeting sleep duration recommendations alone does not eliminate the increased MACE risk for those with irregular sleep schedules,” Chaput explains.
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Expert Analysis
Andrew J. K. Phillips, MD, associate professor at Flinders University College of Medicine and Public Health, notes: “Irregular sleep patterns likely lead to disruption of the body’s network of circadian clocks. These clocks regulate the timing of all kinds of physiological functions throughout the body, including cell metabolism.”
Scott Kutscher, MD, clinical associate professor at Stanford Medicine, recommends practical steps:
- Set a consistent bedtime and wake times.
- Create a wind-down routine.
- Maintain a schedule on weekends.
- Seek medical help for potential sleep disorders.
Scientific Implications
The research methodology used wrist accelerometers for seven days to track sleep patterns. Naveed Sattar, professor of cardiometabolic medicine at the University of Glasgow, cautions about attributing direct causality, noting other lifestyle factors may influence both sleep patterns and cardiovascular health.
This study adds to mounting evidence linking sleep regularity to health outcomes. The Children’s Hospital of Eastern Ontario Research Institute emphasizes incorporating sleep regularity guidelines into public health recommendations.
