Background: Although biological sleep criteria seem to be associated with cognitive changes in older people, it is not clear if subjective sleep parameters are related to cognitive decline in later life.
Objectives: The aim of this study was to determine whether subjective sleep complaints in a population-based sample of 838 middle aged and older adults (>or= 50 years) predicted cognitive decline over a period of 3 years.
Methods: Sleep complaints at baseline, assessed with the subscale Sleep Problems of the Symptoms Checklist-90, were used as a predictor variable. Cognitive performance at follow-up, measured with the Mini Mental Status Examination, was employed as a dependent variable.
Results: Controlling for the effects of age, gender, length of follow-up interval, systemic diseases, and cognitive function at baseline, subjective sleep complaints were negatively associated with cognitive performance at follow-up.
Conclusion: Subjective sleep complaints predict cognitive decline in middle aged and older adults. Mechanisms behind the effect of subjective sleep complaints on cognitive performance are discussed.
Copyright 2002 John Wiley & Sons, Ltd.