Incidence of sleep disorders in patients with Alzheimer disease

To determine the incidence of sleep disorder at a follow-up examination from 1 to 4 years, in demented patients diagnosed at first visit, besides analyzing associated demographic and comorbidities characteristics.

A total of 122 elderly patients aged 60 years or older and diagnosed with dementia (Alzheimer and other) were followed in a reference geriatric center for dementia. The clinical protocols included interviews with patient and caregiver, complete physical examination, laboratory and imaging tests. Criteria for the diagnosis of sleep disorder included complain of insomnia from the patient or caregiver using the Neuropsychiatric Inventory nighttime.

The incidence density of sleep disorder among dements was 18.7/100 person/years. The risk of developing sleep disorder within the frst and fourth years of follow-up was 9.8% and 50.9%, respectively. Multivariate Coxregression analysis revealed that educational level less than 8 years and report of aggressiveness at baseline were an independent predictor of sleep disorder, increased risk in 3.1 (95%CI: 1.30-9.22) and 2.1 times (95%CI: 1.16-4.17), respectively.

The incidence of sleep disorder in demented patients was elevated, and was particularly associated to low educational level and aggressiveness at admission.