To find out how sleep duration, quality and consistency influence various health outcomes, a team of researchers has conducted a new study using data from Google’s Fitbit smartwatch users.
The study, published in the journal Nature Medicine, was based on nearly 6.5 million nights of sleep from more than 6,700 Fitbit users participating in the ‘All of Us Research Programme’ collected over an average of 4.5 years of wear, Google wrote in a blogpost.
The research examines the correlation between sleep and a wide range of human diseases, rather than focusing on a specific set of health outcomes.
The study highlighted six key findings on how sleep impacts people’s health.
1. Sleep duration: The study found that each additional hour of sleep was linked to a reduced likelihood of conditions such as obesity and sleep apnea. However, both too little and too much sleep were associated with various health issues.
2. Sleep stages: The balance of REM, light, and deep sleep, as indicated by Fitbit data, appears to be crucial for heart health and mental well-being.
3. Restless sleep: Increases in Fitbit’s restlessness metric were connected to a higher likelihood of sleep disorders and hypothyroidism.
4. Sleep irregularity: Inconsistent sleep patterns were linked to a wide range of health issues affecting nearly every organ system. Strong associations with sleep irregularity included high blood pressure, obesity, psychiatric disorders (depression, anxiety, bipolar disorder), and migraine headaches.
5. Demographic differences: The study showed significant variations in median sleep duration across different demographics. For example, women tended to sleep longer than men. This highlights the importance of considering individual factors and potential health disparities when studying and promoting sleep health.
6. Lifestyle role: The study also found that lifestyle factors such as smoking and alcohol intake were associated with differences in sleep duration. This emphasizes the interconnectedness of health behaviours and underscores the importance of addressing multiple lifestyle factors to improve sleep and overall well-being.
“While this study is not intended to suggest that Fitbit sleep data is a clinical tool, we think some of these insights will show researchers the benefits of using cost-effective sleep monitors and wearables for studying how changes in sleep patterns over time might affect the health of populations at scale,” said Google.
“And the study continues to be a wake-up call that consistent sleep is as important as getting enough shut-eye,” it added.