Validation and Exploration of Sleep and Mood Predictors
To determine whether objectively recorded sleep durations were mortality risk factors, whether sleep duration could be distinguished from depression as a risk factor in Women's Health Initiative (WHI) data, and whether sleep-associated risks were attributable to specific pathophysiologic processes such as sleep apnea, circadian rhythm phase advances, or deficiencies of melatonin, or deficiencies of reproductive steroids. The study was ancillary to the WHI.
Sleep Apnea Syndromes
|Study Design:||Observational Model: Natural History|
|Study Start Date:||August 1995|
|Estimated Study Completion Date:||July 1999|
Both reported short sleep and reported long sleep are major predictors of excess mortality risk, but the importance of reported sleep duration as a risk factor is not yet known. Sleep-related risks are of special interest to The Women's Health Initiative (WHI), because insomnia increases among women at menopause, and because WHI's hormone replacement therapy (HRT) and dietary modification (DM) may influence sleep. The WHI is an exciting opportunity to examine whether risks associated with reported sleep durations can be explained by a selection of intercurrent conditions, but the broad WHI design does not control for important potential confounders. Explicitly, the broad WHI design by itself cannot determine if behaviorally-modifiable objective sleep durations are the primary risk factor.
This ancillary project supplemented the WHI Observational Study (OS) by performing additional examinations on 600 San Diego OS women. These volunteers underwent home sleep recordings, hormone measurement, and detailed psychiatric interviews. To facilitate distinction of affective and sleep factors in WHI outcomes, the types and severity of depression in the OS subsample and the validity and reliability of sleep items in questionnaires given to WHI women were examined.