Restless legs syndrome and ferritin levels in older adults with dementia: a cross-sectional study.

In cases of dementia or major neurocognitive disorder, restless legs syndrome has not been extensively studied because the diagnosis relies on clinical assessments and self-reports from patients. Objective: The aim of this study was to investigate the association between Willis-Ekbom disease/restless legs syndrome and iron-deficiency anemia in older adults with dementia. Methods: A cross-sectional study was conducted with 70 older adults diagnosed with dementia and restless legs syndrome at a psychogeriatric clinic in the state of São Paulo, Brazil. The participants answered data collection instruments addressing sociodemographic characteristics, restless legs syndrome, neuropsychiatric symptoms, sleep quality, daytime sleepiness, and cognitive function. Creatinine, ferritin, red blood cells, hemoglobin, and hematocrit were determined by blood exams (the latter of which was collected from the patient records). Results: The sample was composed predominantly of individuals with mixed dementia (i.e., Alzheimer's disease+vascular dementia). Women accounted for 55.7% of the sample, with a mean age of 77.80±9.36 years. The prevalence of restless legs syndrome among the participants was found to be 15.7%. Individuals with this syndrome had greater frequencies of neuropsychiatric symptoms, poor sleep quality, higher BMI, and lower ferritin levels (p<0.05). Conclusion: The prevalence of restless legs syndrome among older adults with dementia was 15.7%, and individuals with this syndrome had ferritin deficiency.