Can Sleep Predict Conversion to Mild Cognitive Impairment and Dementia? Results From the Hellenic Longitudinal Investigation of Aging and Diet Study
Styliani Bairami, Nikolaos Scarmeas, Mary Yannakoulia, Efthimios Dardiotis, Paraskevi Sakka, Georgios Hadjigeorgiou, Angeliki Tsapanou, Mary H. KosmidisObjective:
Sleep disturbance is considered a risk factor for cognitive decline in elderly individuals. Our aim in the current study was to investigate whether baseline sleep parameters can predict the conversion from normal cognition to mild cognitive impairment or dementia at follow-up. The Hellenic Longitudinal Investigation of Aging and Diet is a longitudinal population-based study designed to estimate the prevalence and incidence of cognitive decline and dementia in the older Greek population.
Methods:
A total of 955 cognitively normal older adults (aged ≥65 y) were drawn from the Hellenic Longitudinal Investigation of Aging and Diet study. A comprehensive neurological and neuropsychological assessment was conducted at baseline and a mean of 3.1 (SD = 0.85) years later, resulting in 160 individuals diagnosed with mild cognitive impairment and 34 with dementia at follow-up, whereas 761 remained cognitively normal.
Results:
Using Cox regression analyses, no sleep parameters increased the risk of conversion status adjusting for demographics and clinical factors. Napping, however, decreased this risk by 19.3% (
Conclusions:
As several previous studies have proposed, napping constitutes a protective factor against cognitive decline. Thus, clinicians should encourage their elderly patients to adopt this healthy habit.