Mixed
Greater day-to-day intraindividual variability (IIV) in sleep/wake patterns (timing, duration, quality) is consistently associated with poorer physical and mental health outcomes, including higher BMI, obesity, chronic disease, depression, and stress, independent of mean sleep values.
Stop focusing solely on hitting a specific number of hours. Track your sleep consistency. High day-to-day variability in when you sleep and wake is a strong predictor of health issues like obesity, depression, and chronic disease. Aim for regularity in bedtime and wake time, not just total hours.
Correlates most consistently associated with greater IIV in one or more aspects of sleep/wake patterns were: younger age, non-White race/ethnicity, living alone, physical health conditions, higher body mass index, weight gain, bipolar and unipolar depression symptomatology, stress, and evening chronotype; symptoms of insomnia and poor sleep were associated with higher sleep/wake IIV, which was reduced following sleep interventions.
Why this rating
Based on a systematic review of 53 peer-reviewed empirical studies, though many are observational and post-hoc.
Source
Beyond the mean: A systematic review on the correlates of daily intraindividual variability of sleep/wake patterns
Bei Bei et al. · Sleep Medicine Reviews · 2015
DOI 10.1016/j.smrv.2015.06.003
More from this paper
- Sleep interventions, particularly Cognitive Behavioral Therapy for Insomnia (CBT-I), reduce sleep/wake intraindividual variability (IIV), suggesting that stabilizing sleep patterns is a key mechanism of these treatments.Good
- Younger age is consistently associated with greater variability in sleep timing (bedtime and wake time), while older age is associated with less variable sleep patterns.Good
Related findings · Mixed
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