Scientists have identified 16 distinct sleep types, providing new insights into how sleep affects our health and behavior. The study uses data from over 100,000 people wearing activity trackers. It highlights how different sleep patterns, from uninterrupted deep sleep to fragmented insomnia, influence well-being.
Researchers analyzed data collected by smart wristbands through the UK Biobank project. Participants were grouped based on their sleep behaviors, ranging from those who slept uninterruptedly to those with significant nighttime wakefulness.
The study identified seven types of insomnia, offering valuable insights:
- Short-duration insomnia: Linked to impaired neurocognitive function
- Average-duration insomnia: Associated with anxiety and ruminative tendencies
The study also explored how shift work impacts sleep. Irregular working hours disrupted participants’ circadian rhythms, the internal clock regulating sleep-wake cycles. This led to shorter and lower-quality sleep.
THE 16 SLEEP TYPES
Researchers divided sleep behaviors into six broad categories, further refined into 16 distinct subcategories:
Cluster 1: Insomnia with Long Sleep Duration and Midawake
- People wake up in the middle of the night but sleep for an extended period overall.
Cluster 2a and 2b: Shift Workers
- 2a: Irregular sleep schedules
- 2b: Fragmented sleep with short durations
Cluster 3a and 3b: Insomnia Types
- 3a: Insomnia with normal sleep duration
- 3b: Insomnia with short sleep duration, further divided into:
- 3b-1: Difficulty falling asleep again after waking up
- 3b-2: A mix of short wake-ups and prolonged sleeplessness
Cluster 4a and 4b: Periodic and Major Sleep Variations
- 4a: Longer periodic sleep-wake cycles
- 4b: Includes:
- 4b-1: Long sleepers
- 4b-2: Morning people
- 4b-3: Shorter periodic sleep-wake cycles
- 4b-4: Preinsomnia with frequent wake-sleep cycles
- 4b-5: Preinsomnia with fewer interruptions and long wake-ups
- 4b-6: Night people
Cluster 5: Sleep Without Daytime Naps
- Consistently sleeping through the night without daytime naps.
NOTABLE FINDINGS
- Preinsomnia Categories:
- Clusters 4b-4 and 4b-5 were labeled “preinsomnia.”
- Individuals experienced mid-sleep wakefulness, but with different patterns of falling back asleep.
- Shift Workers:
- Clusters 2a and 2b highlighted how irregular schedules disrupt circadian rhythms, leading to fragmented sleep.
- Insomnia Spectrum:
- Short-duration insomnia (3b-2) showed the most severe disruptions, including long hours spent awake after interruptions.
IMPACT OF CIRCADIAN RHYTHM DISRUPTION
When the natural circadian rhythm is out of sync, as seen in shift workers, it can result in:
- Shorter sleep duration
- Poor sleep quality
- Increased risk of cognitive and health issues
WHY DOES THIS MATTER?
Understanding these 16 sleep types provides new opportunities to:
- Tailor interventions for insomnia: Recognizing subcategories helps develop personalized treatments.
- Address shift work challenges: Strategies to minimize circadian disruption could improve health outcomes.
- Raise awareness about preinsomnia: Early detection and prevention could reduce the risk of chronic sleep disorders.