Subjective sleep problems in later life as predictors of cognitive decline. Report from the Maastricht Ageing Study (MAAS).

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 (≥ 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.