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Home / May 2025 / SLEEP AND CARDIOMETABOLIC HEALTH

SLEEP AND CARDIOMETABOLIC HEALTH

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On average, we spend nearly 1/3rd of our lives asleep and as we all know, if we don’t get enough quality sleep, we can feel fatigued, irritable, experience mood changes, find it difficult to concentrate, and/or find it difficult to remember. In addition to these short-term feelings, poor sleep can increase the risk of developing a range of metabolic conditions that may adversely affect our overall health and well-being.
What is sleep?
Sleep is a biologically important reversible state of inactivity associated with reduced responsiveness to the external environment. It is a fundamental biological process that plays a crucial role in maintaining physical, mental, and cognitive health in the human body, but importantly, sleep occurs in all multicellular animals, indicating its universal and fundamental functionality.
How much sleep should we have?
The USAs National Sleep Foundation (NSF) recommend a sleep duration of:
  • 9-11 hours for school-aged children
  • 8-10 hours for teenagers
  • 7-9 hours for young adults and adults, and
  • 7-8 hours for older adults

Additionally, the NSF advise that daily regularity in sleep timing is important for health and performance (physical and mental).

Despite popular perception, sleep-time does not have to occur all in one session, with a bi-modal sleep pattern (e.g. 3-4 hours x 2 asleep, with an hour or two of waking time in between) common amongst humans until the Industrial Revolution.

It’s also useful to know that when sleep is of insufficient duration during the week (or work days), catch-up sleep on weekends (or non-work days) helps.

Sleep and cardiometabolic health

The risk of insufficient and/or poor-quality sleep on diabetes risk and management has been discussed in this month’s Diabetes Care.

Poor sleep can also increase the risk of weight gain and developing cardiovascular disease (CVD). CVD includes coronary heart disease, stroke, and heart failure, which are collectively the leading cause of death, globally.

Sleep and body weight

Observational studies consistently find associations between short sleep duration (6 hours or less per night) and increased risk of obesity (body mass index (BMI) greater than 30 kg/m2). A recent systematic review and meta-analysis of 12 observational studies including 154,936 participants found that short sleep duration was associated with a 41% increased risk of becoming obese.

Sleep and cardiovascular disease

There appears to be a U-shaped relationship between sleep duration and risk of cardiovascular disease, with either too much or too little sleep associated with increased risk.

A recent systematic review and meta-analysis of 15 observational studies including 474,684 participants found that short sleep duration (6 hours or less per night) was associated with a 48% increased risk of developing or dying of coronary heart disease and 15% increased risk of having a stroke. Similar to the risk of developing type 2 diabetes, long duration of sleep (8-9 hours or more per night) is also associated with a 38% increased risk of coronary heart disease (1.38, 1.15–1.66, P ¼ 0.0005), and 65% increased risk of having a stroke.

There is also some evidence from observational studies that poor sleep quality increases the risk of cardiovascular diseases by up to 29%.

Quality sleep is a very important part of cardiometabolic health

When discussing the causes and potential ways of preventing weight gain, type 2 diabetes and cardiovascular diseases, we tend to focus on encouraging more physical activity and improving our diets. While these factors are definitely important, poor sleep increases the risk of these conditions by similar amounts. Therefore, as a society, we need to put equal weight on improving sleep as we do on diets and exercise.

Read more:

  1. Hong and colleagues. The Effect of Sleep Disruption on Cardiometabolic Health. Life, 2025.
  2. Hirshkowitz and colleagues. National Sleep Foundation’s updated sleep duration recommendations: final report. Sleep Health, 2015.
  3. Bacaro and colleagues. Sleep duration and obesity in adulthood: An updated systematic review and meta-analysis. Obesity Research & Clinical Practice, 2020.
  4. Cappuccio and colleagues. Sleep duration predicts cardiovascular outcomes: a systematic review and meta-analysis of prospective studies. Eur Heart J. 2011.
Dr Alan Barclay, PhD, is a consultant dietitian and chef with a particular interest in carbohydrates and diabetes. He is author of Reversing Diabetes (Murdoch Books), and co-author of 40 scientific publications, The Good Carbs Cookbook (Murdoch Books), Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment Publishing).
Contact: Follow him on Twitter, LinkedIn or check out his website.
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