Sleep Cycle and Cardiovascular Disease

Sleep Cycle and Cardiovascular Disease

insomnia tips from DeerFields Clinic

Anthony Barsby MSFc, CEP, R.Kin Pn1

Sleep is a fascinating life phenomenon from its behaviour, to its purpose (has anyone wondered why we dream?) and the potential impacts when we do not get enough. There have been numerous studies validating the importance of sleep and potential consequences from sleep deprivation. For example, poor sleep may be correlated with obesity. In one study, it was concluded that short sleep duration increased the risk of childhood obesity. Children are especially at risk due to the fact that they are still developing and need more sleep than adults. There is an increased risk for weight gain overtime from poor sleep as a result of the alterations that can happen with hormones that control appetite. Furthermore, there has been much debate on what is the “best” sleep cycle for general health and wellbeing, most adults know the recommendation of “8 hours” but when is the best time to sleep for that 8 hours?

Recently Scientists in Europe investigated sleep cycle and cardiovascular disease risks by attaching wrist accelerometer devices to over 88,000 people over a 7-day period, minimizing the potential lack of accuracy in the data. The study was conducted in Britain and included a total of 88,026 participants from 2006 – 2010, 58% being female and the overall average age was 61 y.o. Researchers also took into account and adjusted for cardiovascular disease risk factors such as smoking, diabetes, high cholesterol as well as participants’ sleep preference such as “Early Bird” or “Night Owl”. Sleep
Latency (Sleep latency is the technical term for the length of time it takes you to fall asleep) and Waking Incidence were tracked over the 7-day period via the wrist accelerometer devices.

What was the result? Of the 88,026 participants, 3,172 participants developed Cardiovascular Disease which included heart attacks, strokes and atherosclerosis (narrowing and/or hardening of arteries) and found that these occurrences were highest in participants with sleep times at midnight or later and lowest in those who fell asleep between 10 p.m. and 10:59 p.m. Additionally, there was a 25% higher risk of cardiovascular disease among those who fell asleep at midnight or later versus those who fell asleep between 10 p.m. and 10:59 p.m. Based on this, one would think that going to bed earlier than 10 pm must be even better (more is better right?). Actually, falling asleep before 10 p.m was associated with a 24 percent increased risk comparatively. Researcher’s made another important note on how the Pandemic may have a contributing role in that many individuals are experiencing shifting sleep cycles due to changes in work schedules, home schedules, school schedules, etc. Regardless, the message is clear. First, we need an adequate amount of sleep (8 hours ideally) and secondly, the best time for us as humans to sleep seems to be between 10 – 10:59 pm.

How can I improve my sleep quality? Consider some simple sleep hygiene behaviours below.

● Pick and stick to a hard bedtime
● If you wake up due to urination, avoid drinking fluids 2 hours after bed and empty your bladder before lights out
● Create an evening recovery ritual that replaces stimulation (internet, TV, social media, work) with music, art, literature, aromatherapy, epsom salt bath, meditation)
● Turn down ambient and interior lighting and shut off all electronic screens (cellphone, tablet, monitor, tv) 2 hours before bedtime
● Keep your bedroom DARK, QUIET and COOL (68 degrees F or 18 degrees C) to optimize sleep
Shahram Nikbakhtian, Angus B Reed, Bernard Dillon Obika, Davide Morelli, Adam C Cunningham, Mert Aral, David Plans, Accelerometer-derived sleep onset timing and cardiovascular disease incidence: a UK Biobank cohort study, European Heart Journal -Digital Health, 2021;, ztab088,

Beccuti, G., & Pannain, S. (2011). Sleep and obesity. Current opinion in clinical nutrition and metabolic care, 14(4), 402–412.

Chaput, J. P., Després, J. P., Bouchard, C., & Tremblay, A. (2008). The association between sleep duration and weight gain in adults: a 6-year prospective study from the Quebec Family Study. Sleep, 31(4), 517–523.

Li L, Zhang S, Huang Y, Chen K. Sleep duration and obesity in children: A systematic review and meta-analysis of prospective cohort studies. J Paediatr Child Health. 2017 Apr;53(4):378-385. doi: 10.1111/jpc.13434. Epub 2017 Jan 10. PMID: 28073179.

Anthony Barsby

As our Human Performance Specialist, Anthony provides clients with comprehensive and customized lifestyle coaching through face-to-face consultations and online mentoring. A Certified Exercise Physiologist, Anthony administers fitness assessments and designs exercise programs that address each individual's goals and needs.