Sleep Pattern Trajectories and Incident Mild Cognitive Impairment and Dementia: Results from the HELIAD Study.

Abstract

Objectives: We explored the trajectories of sleep patterns and their relationship with conversion to MCI or dementia in a sample of older adults.

Methods: A total of 1984 participants ( >64 years old) in a population-based, longitudinal study (HELIAD), provided information regarding their sleep patterns. A full neurological exam and a comprehensive neuropsychological assessment were conducted to determine MCI and dementia diagnoses. Baseline and three-year follow-up associations of sleep patterns with cognitive status (healthy, MCI, dementia), age, education and sex were analyzed with the utilization of generalized estimating equation models.

Results: Baseline sleep patterns did not differentiate between initially healthy participants who converted either to MCI or dementia and those who remained healthy at follow-up. Baseline healthy participants who converted to MCI at follow-up reported more frequent sleep quality problems at follow-up than the consistently healthy participants (p = .032). Baseline healthy participants who converted to dementia at follow-up conveyed less frequent sleep disturbances(p = .009), greater sleep adequacy ratings (p = .006) and longer sleep duration (p = .001) at follow-up compared to their consistently healthy counterparts.

Conclusions: Sleep pattern trajectories were not associated with cognitive diagnosis. Sleep pattern alterations do not appear to predate conversion to MCI or dementia among cognitively healthy older adults.

Clinical implications: Discrepancies in self-reports might reflect a compromise in the ability to form objective judgments. These discrepancies may help differentiate between MCI and early dementia.